Journal articles: 'Axes of motion'

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Nishiguchi, Tadahiro, Shogo Hasegawa, Ryuta Sato, and Keiichi Shirase. "Evaluation Method for Behavior of Rotary Axis Around Motion Direction Changing." International Journal of Automation Technology 11, no. 2 (March 1, 2017): 171–78. http://dx.doi.org/10.20965/ijat.2017.p0171.

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Several methods for evaluating the motion accuracy of the rotary axes in five-axis machining centers have been proposed till date. As it is known that particular motion errors exist around the motion direction changing points, it is important to evaluate the behavior of the rotary axes around these points. However, the influence of the motion error in the translational axes is included in the conventional evaluation results, as the translational axes reverse at the motion direction changing points about the rotary axes. In this study, an evaluation method which can assess the behavior of a rotary axis around motion direction changes by synchronous motion of translational and rotary axes is proposed. In this method, the direction of translational axes does not change when the motion direction of a rotary axis changes. A measurement test and actual cutting tests are carried out to clarify the influence of the behaviors of rotary axes on the motion trajectory and machined surface, caused by the change in the motion direction of the rotary axis. Simulations of the motion are also carried out to discuss the causes of inaccuracy.

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Shi, Zhaoyao, Huixu Song, Hongfang Chen, and Yanqiang Sun. "Research on Measurement Accuracy of Laser Tracking System Based on Spherical Mirror with Rotation Errors of Gimbal Mount Axes." Measurement Science Review 18, no. 1 (February 1, 2018): 13–19. http://dx.doi.org/10.1515/msr-2018-0003.

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Abstract This paper presents a novel experimental approach for confirming that spherical mirror of a laser tracking system can reduce the influences of rotation errors of gimbal mount axes on the measurement accuracy. By simplifying the optical system model of laser tracking system based on spherical mirror, we can easily extract the laser ranging measurement error caused by rotation errors of gimbal mount axes with the positions of spherical mirror, biconvex lens, cat’s eye reflector, and measuring beam. The motions of polarization beam splitter and biconvex lens along the optical axis and vertical direction of optical axis are driven by error motions of gimbal mount axes. In order to simplify the experimental process, the motion of biconvex lens is substituted by the motion of spherical mirror according to the principle of relative motion. The laser ranging measurement error caused by the rotation errors of gimbal mount axes could be recorded in the readings of laser interferometer. The experimental results showed that the laser ranging measurement error caused by rotation errors was less than 0.1 μm if radial error motion and axial error motion were within ±10 μm. The experimental method simplified the experimental procedure and the spherical mirror could reduce the influences of rotation errors of gimbal mount axes on the measurement accuracy of the laser tracking system.

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Lewis, Gregory S., H. J. Sommer, and Stephen J. Piazza. "In Vitro Assessment of a Motion-Based Optimization Method for Locating the Talocrural and Subtalar Joint Axes." Journal of Biomechanical Engineering 128, no. 4 (January 17, 2006): 596–603. http://dx.doi.org/10.1115/1.2205866.

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The locations of the joint axes of the ankle complex vary considerably between subjects, yet no noninvasive method with demonstrated accuracy exists for locating these axes. The moments of muscle and ground reaction forces about the joint axes are dependent on axis locations, making knowledge of these locations critical to accurate musculoskeletal modeling of the foot and ankle. The accuracy of a computational optimization method that fits a two-revolute model to measured motion was assessed using computer-generated data, a two-revolute mechanical linkage, and three lower-leg cadaver specimens. Motions were applied to cadaver specimens under axial load while bone-mounted markers attached to the tibia, talus, and calcaneus were tracked using a video-based motion analysis system. Estimates of the talocrural and subtalar axis locations were computed from motions of the calcaneus relative to the tibia using the optimization method. These axes were compared to mean helical axes computed directly from tibia, talus, and calcaneus motions. The optimization method performed well when the motions were computer-generated or measured in the mechanical linkage, with angular differences between optimization and mean helical axes ranging from 1deg to 5deg. In the cadaver specimens, however, these differences exceeded 20deg. Optimization methods that locate the anatomical joint axes of the ankle complex by fitting two revolute joints to measured tibia-calcaneus motions may be limited because of problems arising from non-revolute behavior.

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Hodge, S. J., P. Perfect, G. D. Padfield, and M. D. White. "Optimising the roll-sway motion cues available from a short stroke hexapod motion platform." Aeronautical Journal 119, no. 1211 (January 2015): 23–44. http://dx.doi.org/10.1017/s000192400001023x.

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AbstractThis paper presents findings from research conducted at the University of Liverpool aimed at optimising the motion cues available from a short-stroke hexapod motion platform. Piloted simulations were conducted for a typical helicopter low-speed sidestep manoeuvre. To correctly simulate the sidestep manoeuvre the motion platform must translate laterally at the same time as it rolls. If the motion in these two axes is not properly harmonised then the pilot can experience significant false motion cues. This is a particular concern for short-stroke hexapod platforms, where displacement limits can severely constrain the available lateral travel particularly during motion in multiple axes (e.g. roll and sway). During the experiment the motion filter gains in the roll and sway axes and the roll-axis motion filter break-frequency were varied. Objective and subjective measures of pilot performance and motion fidelity were gathered for each motion filter configuration, the latter using a new motion fidelity rating scale. The key findings show that acceptable motion cues could only be achieved by careful harmonisation of the motion filter gains in the roll and sway axes. A high gain in the roll axis coupled with a low gain in the sway axis resulted in motion which was abrupt and uncomfortable. On the other hand, too large a gain in the sway axis resulted in extreme lateral displacements of the motion platform leading to undesirable side-effects. The phase distortion between the visual and platform motion cues, introduced by the roll-axis motion filter, also had a significant impact on the pilot’s perception of motion fidelity. These results are presented in the form of proposed motion fidelity criteria for short-stroke hexapod platforms and compared with results from previous research conducted on a range of large motion systems.

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Şentürk, Gülsüm Yeliz, and Salim Yüce. "A Geometric Aspect of the Two-Parameter Planar Lorentzian Motions." Mathematical Problems in Engineering 2018 (September 19, 2018): 1–11. http://dx.doi.org/10.1155/2018/7021310.

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We examined the moving coordinate systems, the polar axes, the density invariance of the polar axis transformation, and the curve plotter points and the support function of the two-parameter planar Lorentzian motion. Furthermore, we were concerned with the determination of the motion using the polar axes and analyzed the motion when the density of the polar axes is zero.

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HAYES, M. J. D., and R. G. LANGLOIS. "ATLAS: A NOVEL KINEMATIC ARCHITECTURE FOR SIX DOF MOTION PLATFORMS." Transactions of the Canadian Society for Mechanical Engineering 29, no. 4 (December 2005): 701–9. http://dx.doi.org/10.1139/tcsme-2005-0047.

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Conventional training simulators commonly use the hexapod configuration to provide motion cues. While widely used, studies have shown that hexapods are incapable of producing the range of motion required to achieve high fidelity simulation required in many applications. This paper presents an overview of the Atlas platform: a novel six DOF motion platform architecture. Orienting is decoupled from positioning, and unlimited rotations are possible about every axis of the mechanism. The decoupling is accomplished by fixing a three DOF spherical orienting device, called the Atlas sphere, on a gantry with three linear axes. The key to the design is three omni-directional wheels in an equilateral arrangement, which impart angular motions to a sphere, thereby providing rotational actuation. The omni-wheels and their castor rollers provide virtually friction-free motion parallel to each omni-wheel rotation axis creating the possibility for unconstrained rotational motion. Since the Atlas sphere rests on these omni-wheels, there are no joints or levers constraining its motion, allowing full 360° motion about all axes. The motivation, architecture, and potential applications for this motion platform are described.

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Sato, Ryuta, and Masaomi Tsutsumi. "High Performance Motion Control of Rotary Table for 5-Axis Machining Centers." International Journal of Automation Technology 1, no. 2 (November 5, 2007): 113–19. http://dx.doi.org/10.20965/ijat.2007.p0113.

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We discuss motion control techniques of rotary tables for 5-axis machining centers. Three translational axes and two rotary ones are controlled simultaneously in the machining of complex shapes such as impellers. A tilting rotary table powered by a worm gear is generally used as the rotary axes for 5-axis machining centers, and various causes of inaccuracy exist in the rotary axes. In this study, we clarified three causes of inaccuracy exists in the rotary axis: rotational fluctuation in the worm gear, backlash, and measurement delay of rotary encoder for feedback. Motor torque saturation of the rotary axis also causes a problem when rotational velocity is changed rapidly. Based upon investigated results, we propose compensators for improving synchronous accuracy. We avoid torque saturation in the rotary axis through acceleration-deceleration design. To verify the effectiveness of the proposed compensators, we applied them to an experimental set-up including a rotary axis. As the results of experiments, it is clarified that the proposed compensators improve the synchronous accuracy of translational and rotary axes.

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Tomizuka, Masayoshi, Jwu-Sheng Hu, Tsu-Chih Chiu, and Takuya Kamano. "Synchronization of Two Motion Control Axes Under Adaptive Feedforward Control." Journal of Dynamic Systems, Measurement, and Control 114, no. 2 (June 1, 1992): 196–203. http://dx.doi.org/10.1115/1.2896515.

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In this paper, motion synchronization of two d-c motors, or motion control axes, under adaptive feedforward control is considered. The adaptive feedforward control system for each axis consists of a proportional feedback controller, an adaptive disturbance compensator and an adaptive feedforward controller. If the two adaptive systems are left uncoupled, a disturbance input applied to one of the two axes will cause a motion error in the disturbed axis only, and the error becomes the synchronization error. To achieve a better synchronization, a coupling controller, which responds to the synchronization error, i.e., the difference between the two motion errors, is introduced. In this case, when a disturbance input is applied to one axis, the motion errors appear in the undisturbed axis as well as in the disturbed axis. The motion error in the undisturbed axis is introduced by the coupling controller and the adaptive feedforward controller. The adaptive synchronization problem is formulated and analyzed in the continuous time domain first, and then in the discrete time domain. Stability conditions are obtained. Effectiveness of the adaptive synchronization controller is demonstrated by simulation.

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Wu, Wei, Toshiki Hirogaki, and Eiichi Aoyama. "Proposal of Improving Method of Rotational 2-Axis Synchronous Accuracy of Plate Motion Control with a Dual Arm Robot by Estimating Ball Rolling Motion on the Plate." Key Engineering Materials 523-524 (November 2012): 889–94. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.889.

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Recently, developers of machining tools have begun paying more and more attention to multi-joint dual-arm robot, and it is expected the robot will reclaim its place in the field of new automation. Industrial dual-arm robots have therefore gained attention as new tools to control both linear motion and rotational motion accurately. On the other hand, the five-axis control machining center controlling the motion of three translation axes and two rotation axes has put into wide practical use. However, a one problem has been that it may be the difficult to measure the synchronic accuracy of rotation two axes without high accuracy gyro sensor. In the present report, we proposed a novel method to measure the synchronic accuracy of rotation two axes of machine tool table with a ball, which keeps a ball rolling around a circular path on the working plate by dual-arm cooperating control. As a result, we investigated an influence of each axis motion error on a ball- rolling path, and demonstrated this method made it feasible to estimate the synchronic accuracy of rotation two axes of machine tool table.

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Stewart, Jonathan P., Norman A. Abrahamson, Gail M. Atkinson, Jack W. Baker, David M. Boore, Yousef Bozorgnia, Kenneth W. Campbell, et al. "Representation of Bidirectional Ground Motions for Design Spectra in Building Codes." Earthquake Spectra 27, no. 3 (August 2011): 927–37. http://dx.doi.org/10.1193/1.3608001.

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The 2009 NEHRP Provisions modified the definition of horizontal ground motion from the geometric mean of spectral accelerations for two components to the peak response of a single lumped mass oscillator regardless of direction. These maximum-direction (MD) ground motions operate under the assumption that the dynamic properties of the structure (e.g., stiffness, strength) are identical in all directions. This assumption may be true for some in-plan symmetric structures, however, the response of most structures is dominated by modes of vibration along specific axes (e.g., longitudinal and transverse axes in a building), and often the dynamic properties (especially stiffness) along those axes are distinct. In order to achieve structural designs consistent with the collapse risk level given in the NEHRP documents, we argue that design spectra should be compatible with expected levels of ground motion along those principal response axes. The use of MD ground motions effectively assumes that the azimuth of maximum ground motion coincides with the directions of principal structural response. Because this is unlikely, design ground motions have lower probability of occurrence than intended, with significant societal costs. We recommend adjustments to make design ground motions compatible with target risk levels.

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Alaci, Stelian, Florina-Carmen Ciornei, Sorinel-Toderas Siretean, Mariana-Catalina Ciornei, and Gabriel Andrei Ţibu. "Dynamical analysis of a 2-degrees of freedom spatial pendulum." MATEC Web of Conferences 184 (2018): 01003. http://dx.doi.org/10.1051/matecconf/201818401003.

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A spatial pendulum with the vertical immobile axis and horizontal mobile axis is studied and the differential equations of motion are obtained applying the method of Lagrange equations. The equations of motion were obtained for the general case; the only simplifying hypothesis consists in neglecting the principal moments of inertia about the axes normal to the oscillation axes. The system of nonlinear differential equations was numerically integrated. The correctness of the obtained solutions was corroborated to the dynamical simulation of the motion via dynamical analysis software. The perfect concordance between the two solutions proves the rightness of the equations obtained.

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Bucher, Manfred. "The dynamical axes of Kepler motion." European Journal of Physics 37, no. 6 (October 13, 2016): 065007. http://dx.doi.org/10.1088/0143-0807/37/6/065007.

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Harris, Laurence R., and Lori A. Lott. "Sensitivity to full-field visual movement compatible with head rotation: Variations among axes of rotation." Visual Neuroscience 12, no. 4 (July 1995): 743–54. http://dx.doi.org/10.1017/s0952523800009007.

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AbstractMovement detection thresholds for full-field visual motion about various axes were measured in three subjects using a two-alternative forced-choice staircase method. Thresholds for 1-s exposures to rotation about different rotation axes varied significantly over the range 0.139 ± 0.05 deg/s to 0.463 ± 0.166 deg/s. The highest thresholds were found in response to rotation about axes closely aligned to the line of sight. Variations among the thresholds for different axes could not be explained by different movement patterns in the fovea or variations in motion sensitivity with eccentricity. The variations can be well simulated by a three-channel model for coding the axis and velocity of full-field visual motion. A three-channel visual coding system would be well suited for extracting information about self-rotation from a complex pattern of retinal image motion containing components due to both rotation and translation. A three-channel visual motion system would also be readily compatible with vestibular information concerning self-rotation arising from the semicircular canals.

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Kamisato, Shihoko, Satoru Odo, Yoshino Ishikawa, and Kiyoshi Hoshino. "Extraction of Motion Characteristics Corresponding to Sensitivity Information Using Dance Movement." Journal of Advanced Computational Intelligence and Intelligent Informatics 8, no. 2 (March 20, 2004): 168–80. http://dx.doi.org/10.20965/jaciii.2004.p0168.

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This study is intended to quantitatively clarify the relationship between the motion characteristics behind the human motion in complicated motions like dancing and the subjective impressions of the observer. It examines the impression structures related to the motion of a determined body part of dancing and considers the motion characteristics giving a specific impression. To compare and consider the impression structures related to the motion of a body part, the authors made a principal component analysis, one of the multi-variable analytic methods, to check the arm and leg motions for any differences in the impression structure. Similarly, they considered any differences in the impression structures due to the experience knowledge of dance. Next, to consider any differences in the physical features that have effect on the impressions, they quantified the motion characteristics and used a heavy regression analysis to estimate the common motion characteristics that give the same impressions. In addition, they used the characteristics of the legs that are parts of the motion presumed to have the relationship with the impressions to reproduce the motion with CG for the consideration of these impressions. As a result, when the impressions of the arm and leg motions were compared, four impression evaluation axes of "like-dislike," "dynamic-static," "individual-monotonous," and "collected-wide" were extracted as the axes that evaluated the same impressions, but the impressions of "hard-soft" and "heavy-light" were extracted only from those of each arm or leg motion. When the evaluation axes of the impressions were compared between groups with differences in the knowledge of dance, five similar evaluation axes were extracted for each of them and there was no big difference in the impression structures themselves, but significant differences were found for the evaluation of impressions between the words used for the sensitivity evaluation in difference in knowledge. Attention was paid to the characteristics of the motion generating each impression to show the relationship between motion characteristics and subjective impressions.

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Kenno, Takaaki, Ryuta Sato, Keiichi Shirase, Shigemasa Natsume, and Henny Spaan. "Identification Method of Error Motions and Geometric Errors of a Rotary Axis by R-Test." International Journal of Automation Technology 14, no. 3 (May 5, 2020): 399–408. http://dx.doi.org/10.20965/ijat.2020.p0399.

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While evaluating the accuracy of high-precision machine tools, it is critical to reduce the error factors contributing to the measured results as much as possible. This study aims to evaluate both the error motions and geometric errors of the rotary axis without considering the influence of motion error of the linear axis. In this study, only the rotary axis is moved considering two different settings of a reference sphere, and the linear axes are not moved. The motion accuracy of the rotary axis is measured using the R-test device, both the error motions and geometric errors of the rotary axis are identified from the measurement results. Moreover, the identified geometric errors are verified for correctness via measurement with an intentional angular error. The results clarify that the proposed method can identify the error motions and geometric errors of a rotary axis correctly. The method proposed in this study can thus be effective for evaluating the motion accuracy of the rotary axis and can contribute to further improvement of the accuracy of the rotary table.

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Ibaraki, Soichi, and Ce Fu Hong. "Thermal Test for Error Maps of Rotary Axes by R-Test." Key Engineering Materials 523-524 (November 2012): 809–14. http://dx.doi.org/10.4028/www.scientific.net/kem.523-524.809.

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Thermal distortions are regarded as one of major error factors in a machine tool. ISO 230-3 [1] describes tests to evaluate the influence of thermal distortions caused by linear motion and spindle rotation on the tool center position (TCP). No test is described in these standards on the thermal influence of a rotary axis. Furthermore, conventional thermal tests only measure thermal influence on the positioning error at a single point, not error motions of an axis. This paper proposes a method to calibrate thermal influence on error motions of rotary axes in five-axis kinematics by the static R-test. The R-test measurement clarifies how error motions of a rotary table changes with the rotation of a swiveling axis, and how error motions are influenced by thermal changes. Experimental demonstration will be presented.

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Chen, Yong, Mei Fa Huang, Bo Shi, Meng Meng Xiao, Ru Kai Hu, and Jiang Sheng Tang. "Kinematic Analysis and Simulation of an A/C Axes Bi-Rotary Milling Head with Zero Transmission." Advanced Materials Research 625 (December 2012): 146–50. http://dx.doi.org/10.4028/www.scientific.net/amr.625.146.

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Because of the flexible kinematic characteristic of five-axis-linkage machining center it is widely used to process complex parts. The milling head is the key functional component of the five-axis machining center, therefore study of the milling head is of vital importance. The A/C axes bi-rotary milling head is the most common used structures. The current mechanical A/C axes bi-rotary milling head is mostly with large volume and small rotation range. This paper presents an A/C axes bi-rotary milling head with zero transmission in small volume. To understand the kinetic characteristics of the A/C axes bi-rotary milling head with zero transmission, we apply D-H parameter method to establish displacement equations, speed equations, and acceleration equations. SolidWorks is then utilized to build the virtual prototyping model of the designed mechanism. Motion module of SolidWorks is also used to carry out the kinematics simulation. The experimental results show that the mechanism could achieve the rotation of A/C axes and smooth motion trajectory. The rotation range of A-axis could reach ±120°.

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Zhang, Shuang Biao, Xing Cheng Li, Zhong Su, and Liang Yu Zhao. "Research on Spiral Motion of Guided Projectiles Based on Flight Data." Applied Mechanics and Materials 229-231 (November 2012): 638–43. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.638.

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To investigate the realistic spiral motion of a spinning guided projectile, a novel analysis method based on flight data is proposed and further applied. A mathematical model of spiral motion is derived in body coordinate system firstly, and the procedures of the novel method are then described in detail. The spiral motion can be induced by non-zero velocity and rotation rate along the longitudinal axis with at least one non-zero velocity and rotation rate along transverse axes. In the case of non-zero velocities and rotation rates exerted along triple axes, it is observed that the spiral motion consists of single circular motion and double circular motion, and the spiral motion depends on both spinning rate and attitude angles of flight trajectory.

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Wang, De Sheng, Ai Ping Zhou, and Yong Jun Zhao. "Research on NC Grinding Accessories of Isometric Polygonal Profile." Key Engineering Materials 416 (September 2009): 93–97. http://dx.doi.org/10.4028/www.scientific.net/kem.416.93.

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In order to study the grinding technology of Isometric Polygonal Profile (IPP), NC grinding accessory of IPP is developed, which is driven by Program Logic Controller (PLC) and step-motors. On the basis of the principle of coordinate conversion and envelope curve, formative motions of IPP are discussed in detail. Because the relationship between the rotation of parts and synchronization motion in both x and y axes of coordinates frame is of the proportional transmission, and the synchronization motion is harmonic motion in both x and y axes of coordinates frame, the relationship of them is of the proportional transmission too, but the frequency of the synchronization motion is low and the displacement is small, so the eccentric mechanism is used in the grinding accessory. The grinding process of three axes linkage of IPP can be translated into process of two axes linkage between three coordinates on machine tools by means of combination of PLC and the eccentric mechanism. It has been found by grinding experiment that the NC grinding accessory is available used for grinding IPP and other polygonal profile.

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Yeh, Syh-Shiuh, and Pau-Lo Hsu. "Perfectly Matched Feedback Control and Its Integrated Design for Multiaxis Motion Systems." Journal of Dynamic Systems, Measurement, and Control 126, no. 3 (September 1, 2004): 547–57. http://dx.doi.org/10.1115/1.1789970.

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For motion systems with multiple axes, the approach of matched direct current gains has been generally adopted to improve contouring accuracy under low-speed operations. To achieve high-speed and high-precision motion in modern manufacturing, a perfectly matched feedback control (PMFBC) design for multiaxis motion systems is proposed in this paper. By applying stable pole-zero cancellation and including complementary zeros for uncancelled zeros for all axes, matched dynamic responses across the whole frequency range for all axes are achieved. Thus, contouring accuracy for multiaxis systems is guaranteed for the basic feedback loops. In real applications, the modeling error is unavoidable and the degradation and limitations of the model-based PMFBC exist. Therefore, a newly designed digital disturbance observer is proposed to be included in the proposed PMFBC structure for each axis to compensate for undesirable nonlinearity and disturbances to maintain the matched dynamics among all axes for the PMFBC design. Furthermore, the feedforward control loops zero phase error tracking controller are employed to reduce tracking errors. Experimental results on a three-axis CNC machining center indicate that both contouring accuracy and tracking accuracy are achieved by applying the present PMFBC design.

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Suzuki, Takamaru, Kazuki Yoshikawa, Toshiki Hirogaki, Eiichi Aoyama, and Takakazu Ikegami. "Improved Method for Synchronizing Motion Accuracy of Linear and Rotary Axes Under Constant Feed Speed Vector at End Milling Point – Investigation of Motion Error Under NC-Commanded Motion –." International Journal of Automation Technology 13, no. 5 (September 5, 2019): 679–90. http://dx.doi.org/10.20965/ijat.2019.p0679.

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A 5-axis machining center (5MC) is noted for its synchronous control capability, making it a feasible tool for quickly and accurately machining complicated three-dimensional surfaces such as propellers and hypoid gears as it is equipped with a direct-drive (DD) motor in the rotary axis. The current research work identified the necessity of improving both the accuracy of the machined shape and the consistency of the free-form machined surface. A method for maintaining the feed speed vector at the milling point by controlling two linear axes and the rotary axis of a 5MC to improve the quality of the machined surface was investigated. Additionally, a method was proposed for reducing the shape error of machined workpieces by considering differences in the servo characteristics of the three axes. The shape error was significantly reduced by applying the proposed method using a precedent control coefficient determined via calculations. To maintain the feed speed vector at the milling point in the machining of complex shapes, rapid velocity change in each axis is often required, leading to inaccuracy caused by torque saturation at a DD motor in the rotary axis. The results of this study indicate that torque saturation can be evaluated via simulation and that the machining accuracy and consistency can be improved by accounting for these errors using the proposed precedent control coefficient method.

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Morishige, Koichi, and Makoto Kaneko. "Tool Path Generation for Five-Axis Controlled Machining with Consideration of Motion of Two Rotational Axes." International Journal of Automation Technology 5, no. 3 (May 5, 2011): 412–19. http://dx.doi.org/10.20965/ijat.2011.p0412.

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In this paper, the original configuration space is applied to generate tool path, which indicate locations of two rotational axes of a 5-axis controlled machine tool. Moreover, A-star algorithm that is one of the methods for route searching is applied to decide tool postures considering the motion of two rotational axes. The developed method can generate tool path limiting the number of used rotational axes, and reducing the moving amount of two rotational axes. Furthermore, the method can generate tool path that avoids the reverse rotation of two rotational axes, which might cause the machining error. As a result, an excellent finished surface is actually obtained, and the usefulness of the developed method is confirmed.

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Sato, Ryuta, and Masaomi Tsutsumi. "Motion Control Techniques for Synchronous Motions of Translational and Rotary Axes." Procedia CIRP 1 (2012): 265–70. http://dx.doi.org/10.1016/j.procir.2012.04.048.

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Paddan, G. S., and M. J. Griffin. "The Transmission of Translational Seat Vibration to the Head: The Effect of Measurement Position at the Head." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 206, no. 3 (September 1992): 159–68. http://dx.doi.org/10.1243/pime_proc_1992_206_283_02.

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Head motion has been measured in six axes on twelve subjects exposed to vertical seat vibration in the frequency range 0.5–25 Hz. The subjects sat on a rigid flat seat in two postures: ‘back-off’ (no backrest) and ‘back-on’ (subject's back in contact with the seat backrest). Translational acceleration has been calculated for various locations on the head and transmissibilities between vertical seat vibration and translational head motion determined for each location and all axes. The translational motion of the head was most affected by pitch motion of the head. This caused variations in fore-and-aft motion with position along the vertical axis of the head and variations in vertical motion with position along the fore-and-aft axis of the head. These variations are illustrated for each subject in both postures. The individual data allow the identification of various modes of vibration and show that seat-to-head transmissibility is greatly affected by pitch modes of the head and neck. The magnitude of motion occurring in some modes is dependent on body posture.

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Angeles, J., S. Caro, W. Khan, and A. Morozov. "Kinetostatic Design of an Innovative Schönflies-Motion Generator." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 220, no. 7 (July 1, 2006): 935–43. http://dx.doi.org/10.1243/09544062jmes258.

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In this paper, a novel parallel robot is introduced. The robot, a Schönflies-motion generator (SMG), is capable of a special class of motions, namely those produced with serial robots termed SCARA (selective-compliance assembly robot arm). These motions involve three independent translations and one rotation about an axis of fixed direction. Such motions are known to form a subgroup of the displacement group of rigid-body motions, termed the Schönflies subgroup. The SMG is composed of two identical four-degree-of-freedom serial chains in a parallel array, sharing one common base and one common moving platform. The proximal module of each chain is active and has two controlled axes, the motors being installed on the fixed base. The links can thus be made light, thereby allowing for higher operational speeds. The distal module, in turn, is passive and follows the motions of its active counterpart, the whole mechanism giving, as a result, a four-degree-of-freedom motion to its end platform.

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RUPPERTSBERG, ALEXA I., SOPHIE M. WUERGER, and MARCO BERTAMINI. "The chromatic input to global motion perception." Visual Neuroscience 20, no. 4 (July 2003): 421–28. http://dx.doi.org/10.1017/s0952523803204077.

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For over 30 years there has been a controversy over whether color-defined motion can be perceived by the human visual system. Some results suggest that there is no chromatic motion mechanism at all, whereas others do find evidence for a purely chromatic motion mechanism. Here we examine the chromatic input to global motion processing for a range of color directions in the photopic luminance range. We measure contrast thresholds for global motion identification and simple detection using sparse random-dot kinematograms. The results show a discrepancy between the two chromatic axes: whereas it is possible for observers to perform the global motion task for stimuli modulated along the red–green axis, we could not assess the contrast threshold required for stimuli modulated along the yellowish-violet axis. The contrast required for detection for both axes, however, are well below the contrasts required for global motion identification. We conclude that there is a significant red–green input to global motion processing providing further evidence for the involvement of the parvocellular pathway. The lack of S-cone input to global motion processing suggests that the koniocellular pathway mediates the detection but not the processing of complex motion for our parameter range.

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Oxland, T. R., M. M. Panjabi, and R. M. Lin. "Axes of Motion of Thoracolumbar Burst Fractures." Journal of Spinal Disorders 7, no. 2 (April 1994): 130–38. http://dx.doi.org/10.1097/00002517-199407020-00006.

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Deehan, David John, K. Milton Ghosh, Alasdair Blain, Lee Longstaff, and Steven Rushton. "Sagittal flexion arc evaluation for a modern generation single-radius femoral component design." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 232, no. 4 (February 23, 2018): 412–17. http://dx.doi.org/10.1177/0954411918759136.

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Single-radius femoral total knee design aims to deliver improved kinematic behaviour when compared to the standard two-radii geometry. This study has evaluated the behaviour, through a functional range of motion in the sagittal plane, of a single-radius femoral component compared to a dual-radius standard knee construct. Particular focus was placed on how the flexion axes of the native and replaced knee approximated to the transepicondylar axis through a loaded navigated knee design. Significant differences in flexion arcs were noted between the native and total knee arthroplasty state. These arcs were not uniform in all knees and did not display single-radius behaviour. There were no significant differences in the location of flexion axes in the native and total knee arthroplasty knee. Both exhibited similar posterior and inferior transverse axes of motion with respect to the anatomical epicondylar axis. This work has cast doubt on the reliability under loaded conditions of the single-radius concept, but the close proximity of the flexion axes of each replaced knee in relation to the functional flexion axis of the native knee may be the true basis of this purported improved kinematic performance.

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Zhou, Cheng Long, Xing Song Wang, and Yu Liang Mao. "Motion Control System and Control Algorithm of 3-Axes Platform Based on Controller Area Network." Applied Mechanics and Materials 532 (February 2014): 196–99. http://dx.doi.org/10.4028/www.scientific.net/amm.532.196.

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3-axes motion is broadly used in industry numerical control machine. Many motion controller we use are usually limited by the number of interface it consist. But the kind of motion controller based on CAN (Controller Area Network ) can solve this problem properly. We can add a controller of one axe conveniently. I use a Advantech CAN motion controller to build the motion control system.

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Deng, Lu Hua, Jun Hui Li, and Ling Gang Liu. "Research of Multi-Axes Motion Control System Based on LabVIEW Platform." Advanced Materials Research 569 (September 2012): 763–68. http://dx.doi.org/10.4028/www.scientific.net/amr.569.763.

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According to Dynamic Link Library (DLL), the common motion card was successfully run on Labview virtual platform, which can graphically compile program. Based on Labview8.6 platform, Leadtech SMC-6480 control card and Yaskawa SJME-02AMA41 servo motor were used as the hardware to realize multi-axes motion control. The results indicated that each axis has three motion models of automatic, manual and return-to-zero, which can switch mutually at any time.

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Hu, Lian Jun, Xiao Hui Zeng, Gui Xu Chen, and Hong Song. "The Research on Multi-Axes Automatic Motion Control Systems." Advanced Materials Research 459 (January 2012): 75–78. http://dx.doi.org/10.4028/www.scientific.net/amr.459.75.

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An automatic control system for multi-axes motions based on multi-CPU embedded systems is proposed in the paper, in order to overcome insufficiencies of available multi-axes automatic dispensing control systems. It is shown from experimental results that expected control objectives for multi-axes motions are achieved.

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K. Bhiwapurkar, Mahesh, V. H. Saran, and Suraj P. Harsha. "Seat to Head Transmissibility during Exposure to Vertical Seat Vibration: Effects of Posture and Vibration Magnitude." March 24, No 1 (March 2019): 3–11. http://dx.doi.org/10.20855/ijav.2019.24.11108.

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The low frequency vibration transmitted to the body can affect the comfort, performance, and health of humans. In this paper, the effect of variations in posture and vibration magnitude on the head motion in three translational axes (fore-and-aft, lateral and vertical) has been studied with a vertical seat vibration. Thirty healthy male subjects were exposed to random vibration with three vibration magnitudes of 0.4, 0.8, and 1.2 m/s2 rms over the frequency range of 1–20 Hz. The results are analysed in terms of seat-to-head-transmissibility (STHT) for the head motions in two seated postures (backrest and leaning forward on table). The measurement of the head motion was made with an apparatus (bite-bar) specifically developed for this purpose. The measured responses to a single axis seat vibration have also shown notable cross-axis responses in both vertical and fore-and-aft axes for both postures. The crossaxis fore-aft and vertical STHT responses showed single peak near 5 Hz in both postures. An increasing intensity of vibration yields a non-linear softening effect in the muscle tension, particularly in the presence of back support, however, the body stiffens under a greater upper body motion in the forward leaning posture. The combined effect of the unsupported back and hands support was observed to be more pronounced around the resonance peak in the forward lean posture.

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Miller, Jonathan, Simon Fletcher, Andrew Longstaff, and Simon Parkinson. "Simultaneous Constant Velocity Measurement of the Motion Errors of Linear Axes." International Journal of Automation Technology 14, no. 3 (May 5, 2020): 417–28. http://dx.doi.org/10.20965/ijat.2020.p0417.

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The current standard for machine tool calibration supports the use of quasi-static measurement techniques. When measuring the six degrees of freedom motion errors, the measurements are typically taken consecutively. This introduces uncertainty when comparing the results due to machine deformation during individual measurements. Furthermore, quasi-static measurement techniques are known to be time consuming, a problem that is exacerbated as each degree of freedom must be measured separately. Additionally, the spatial resolution between the selected target positions can have an impact on calibration quality. In the following paper, the benefits of measuring the six motion errors simultaneously while the axis under test is traversing at a nominally constant velocity are presented. Firstly, the motivation for simultaneous continuous capture is presented. Secondly, continuous motion measurements are compared with quasi-static measurements for the six degrees of freedom motion errors showing sub-micrometer and sub-arcsecond correlation. The full effect of a ball screw pitch error is shown which can be missed using traditional quasi-static measurement techniques. Finally, wavelet analysis is performed for further spatial diagnostics along with correlation coefficients calculated to quantify the linear dependency between the six error motions.

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White, K. Ian, Valeria Bugris, Andrew A. McCarthy, Raimond B. G. Ravelli, Krisztián Csankó, Alberto Cassetta, and Sandor Brockhauser. "Calibration of rotation axes for multi-axis goniometers in macromolecular crystallography." Journal of Applied Crystallography 51, no. 5 (September 13, 2018): 1421–27. http://dx.doi.org/10.1107/s1600576718010956.

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The installation of multi-axis goniometers such as the ESRF/EMBL miniKappa goniometer system has allowed the increased use of sample reorientation in macromolecular crystallography. Old and newly appearing data collection methods require precision and accuracy in crystal reorientation. The proper use of such multi-axis systems has necessitated the development of rapid and easy to perform methods for establishing and evaluating device calibration. A new diffraction-based method meeting these criteria has been developed for the calibration of the motors responsible for rotational motion. This method takes advantage of crystal symmetry by comparing the orientations of a sample rotated about a given axis and checking that the magnitude of the real rotation fits the calculated angle between these two orientations. Hence, the accuracy and precision of rotational motion can be assessed. This rotation calibration procedure has been performed on several beamlines at the ESRF and other synchrotrons. Some resulting data are presented here for reference.

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Thapa, R. R. "The Stability of Solutions of Sitnikov Restricted Problem of three Bodies When the Primaries are Triaxial Rigid Bodies." Journal of Institute of Science and Technology 19, no. 2 (November 9, 2015): 76–78. http://dx.doi.org/10.3126/jist.v19i2.13856.

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The paper deals with the stability of the solutions of Sitnikov's restricted problem of three bodies if the primaries are triaxial rigid bodies. The infinitesimal mass is moving in space and is being influenced by motion of two primaries (m1>m2). They move in circular orbits without rotation around their centre of mass. Both primaries are considered as axis symmetric bodies with one of the axes as axis of symmetry whose equatorial plane coincides with motion of the plane. The synodic system of co-ordinates initially coincides with inertial system of co-ordinates. It is also supposed that initially the principal axis of the body m1 is parallel to synodic axis and are of the axes of symmetry is perpendicular to plane of motion.Journal of Institute of Science and Technology, 2014, 19(2): 76-78

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Banerjee Basu, Swagata, and Masanobu Shinozuka. "Effect of Ground Motion Directionality on Fragility Characteristics of a Highway Bridge." Advances in Civil Engineering 2011 (2011): 1–12. http://dx.doi.org/10.1155/2011/536171.

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It is difficult to incorporate multidimensional effect of the ground motion in the design and response analysis of structures. The motion trajectory in the corresponding multi-dimensional space results in time variant principal axes of the motion and defies any meaningful definition of directionality of the motion. However, it is desirable to consider the directionality of the ground motion in assessing the seismic damageability of bridges which are one of the most vulnerable components of highway transportation systems. This paper presents a practice-oriented procedure in which the structure can be designed to ensure the safety under single or a pair of independent orthogonal ground motions traveling horizontally with an arbitrary direction to structural axis. This procedure uses nonlinear time history analysis and accounts for the effect of directionality in the form of fragility curves. The word directionality used here is different from “directivity” used in seismology to mean a specific characteristic of seismic fault movement.

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37

Holland, J. B., M. J. D. Hayes, and R. G. Langlois. "A SLIP MODEL FOR THE SPHERICAL ACTUATION OF THE ATLAS MOTION PLATFORM." Transactions of the Canadian Society for Mechanical Engineering 29, no. 4 (December 2005): 711–20. http://dx.doi.org/10.1139/tcsme-2005-0048.

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The Atlas platform represents a novel six degree-of-freedom motion platform architecture. Orienting is decoupled from positioning, and unlimited rotations are possible about every axis. The decoupling is accomplished by fixing a three degree-of-freedom spherical orienting device, called the Atlas sphere, on a gantry with three orthogonal linear axes. The key to the design is three omni-directional wheels in an equilateral arrangement, which impart angular displacement to a sphere, providing rotational actuation. The free-spinning castor rollers provide virtually friction-free motion parallel to each omni-wheel rotation axis creating the potential for unconstrained angular motion. Since the sphere directly contacts the omni-wheels, there are no joints or links interfering with its motion, allowing full 360° motion about all axes. However, the kinematic constraints are non-holonomic. This paper explores the slip at the interface between each omni-wheel and the Atlas sphere. A kinematic slip model is presented, introducing the slip ratio, which is the ratio of the kth omni-wheel’s transverse velocity component, S⊥k, which is perpendicular to the free-spinning castor wheel axis, and the tangential velocity component, Stank, which is perpendicular to the omni-wheel driving axis, parallel to the tangential velocity vector, Vk. The long-term goal is to incorporate the slip model into a control law for position level control of the sphere. Two illustrative examples are given.

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Chen, Xiu Mei, Qiu Shi Han, and Bao Ying Peng. "Research on Cam Contour Error of Grinding Machining." Applied Mechanics and Materials 620 (August 2014): 199–204. http://dx.doi.org/10.4028/www.scientific.net/amm.620.199.

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In order to obtain higher cam quality, the research on the cam contour error is studied. The cam is machined in the way of X-C biaxial linkage motions. The linear motor drives the grinding wheel mechanism to get the motion of X axis, and the motion of C axis is the rotating of cam driven by the torque motor. Because of the servo-system-lag of the two axes, the cam contour error is formed in the X-C biaxial linkage motions. Moreover, the following position error of X axis and C axis is not same as the cam contour error. The relationship between axis following position error and cam contour error is studied. The mathematical model of cam contour error is constructed, the relationship between the cam contour error and the following position error are obtained. At last, the conclusion which the cam contour error can be controlled is made, although the following position error exists at the same time. To design the contour error controller for higher quality cam is based on the above conclusion.

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Hall, Gregory W., Jeff R. Crandall, Gregory S. Klopp, and Walter D. Pilkey. "Angular Rate Sensor Joint Kinematics Applications." Shock and Vibration 4, no. 4 (1997): 223–29. http://dx.doi.org/10.1155/1997/243513.

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High speed rotary motion of complex joints were quantified with triaxial angular rate sensors. Angular rate sensors were mounted to rigid links on either side of a joint to measure angular velocities about three orthogonal sensor axes. After collecting the data, the angular velocity vector of each sensor was transformed to local link axes and integrated to obtain the incremental change in angular position for each time step. Using the angular position time histories, a transformation matrix between the reference frame of each link was calculated. Incremental Eulerian rotations from the transformation matrix were calculated using an axis system defined for the joint. Summation of the incremental Eulerian rotations produced the angular position of the joint in terms of the standard axes. This procedure is illustrated by applying it to joint motion of the ankle, the spine, and the neck of crash dummies during impact tests. The methodology exhibited an accuracy of less than 5% error, improved flexibility over photographic techniques, and the ability to examine 3-dimensional motion.

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ZHAO, Zhi Min, Takuya KAMANO, Takayuki SUZUKI, Hironobu HARADA, and Yu KATAOKA. "Synchronization of Two Motion Axes with Disturbance Observers." Transactions of the Institute of Systems, Control and Information Engineers 9, no. 4 (1996): 151–61. http://dx.doi.org/10.5687/iscie.9.151.

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41

Fadul, Faisal, and Louis Arnold. "Modular CNC system for multi-axes motion devices." Computers in Industry 20, no. 2 (January 1992): 203–8. http://dx.doi.org/10.1016/0166-3615(92)90054-q.

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42

Teixeira, Ralph Costa. "Medial Axes and Mean Curvature Motion II: Singularities." Journal of Mathematical Imaging and Vision 23, no. 1 (July 2005): 87–105. http://dx.doi.org/10.1007/s10851-005-4969-0.

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43

Ma, Dong, Jiakun Li, Qibo Feng, Qixin He, Yaowen Ding, and Jianying Cui. "Simultaneous Measurement Method and Error Analysis of Six Degrees of Freedom Motion Errors of a Rotary Axis Based on Polyhedral Prism." Applied Sciences 11, no. 9 (April 27, 2021): 3960. http://dx.doi.org/10.3390/app11093960.

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A novel method is proposed for measuring the six degrees-of-freedom (DOF) geometric motion errors of a rotary axis based on a polyhedral prism. An error-sensitive unit which consists of a polyhedral prism and a planar reflector, is designed to carry out measurement of all six DOF errors, including the angular positioning error, the tilt motion error around the Y axis, the tilt motion error around the X axis, the radial motion error along the X and Y axes, and the axial motion error along the Z axis. The mathematical error model, including the six DOF geometric motion errors of the rotary axis, the installation errors between the polyhedral prism and the rotary axis, the manufacturing errors of the polyhedral prism, and the position errors of the sensors, are established. The effectiveness of the proposed method and the compensation model was simulated and experimentally verified.

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44

Dickman, Curtis A., Neil R. Crawford, and Christopher G. Paramore. "Biomechanical characteristics of C1–2 cable fixations." Journal of Neurosurgery 85, no. 2 (August 1996): 316–22. http://dx.doi.org/10.3171/jns.1996.85.2.0316.

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✓ The biomechanical characteristics of four different methods of C1–2 cable fixation were studied to assess the effectiveness of each technique in restoring atlantoaxial stability. Biomechanical testing was performed on the upper cervical spines of four human cadaveric specimens. Physiological range loading was applied to the atlantoaxial specimens and three-dimensional motion was analyzed with stereophotogrammetry. The load–deformation relationships and kinematics were measured, including the stiffness, the angular ranges of motion, the linear ranges of motion, and the axes of rotation. Specimens were nondestructively tested in the intact state, after surgical destabilization, and after each of four different methods of cable fixation. Cable fixation techniques included the interspinous technique, the Brooks technique, and two variants of the Gallie technique. All specimens were tested immediately after fixation and again after the specimen was fatigued with 6000 cycles of physiological range torsional loading. All four cable fixation methods were moderately flexible immediately; the different cable fixations allowed between 5° and 40° of rotational motion and between 0.6 and 7 mm of translational motion to occur at C1–2. The Brooks and interspinous methods controlled C1–2 motion significantly better than both of the Gallie techniques. The motion allowed by one of the Gallie techniques did not differ significantly from the motion of the unfixed destabilized specimens. All cable fixation techniques loosened after cyclic loading and demonstrated significant increases in C1–2 rotational and translational motions. The bone grafts shifted during cyclic loading, which reduced the effectiveness of the fixation. The locations of the axes of rotation, which were unconstrained and mobile in the destabilized specimens, became altered with cable fixation. The C1–2 cables constrained motion by shifting the axes of rotation so that C-1 rotated around the fixed cable and graft site. After the specimen was fatigued, the axes of rotation became more widely dispersed but were usually still localized near the cable and graft site. Adequate healing requires satisfactory control of C1–2 motion. Therefore, some adjunctive fixation is advocated to supplement the control of motion after C1–2 cable fixation (that is, a cervical collar, a halo brace, or rigid internal fixation with transarticular screws).

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Sun, Dong. "Adaptive Coupling Control of Two Working Operations in CNC Integrated Machines*." Journal of Dynamic Systems, Measurement, and Control 125, no. 4 (December 1, 2003): 662–65. http://dx.doi.org/10.1115/1.1636779.

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To reduce work in progress in the plastic industry, integrated CNC punching and cutting machines have been used recently to combine a number of individual operations into one operation. Application of such integrated machines is confronted with a challenging problem of synchronizing two-axis motions. In this paper, an adaptive coupling controller is utilized to synchronize punching and cutting operations of the integrated CNC machine. The controller incorporates cross-coupling technology into adaptive control design, through feedback of position errors of two motion axes and the differential position error between two axes. It has been shown that the proposed controller guarantees asymptotic convergence to zero of both position errors and the synchronization error. Implementation of this new controller in real-time operations of commercial integrated CNC machines, highlights advantages of the proposed approach.

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46

Goldfarb, M., and J. E. Speich. "A Well-Behaved Revolute Flexure Joint for Compliant Mechanism Design." Journal of Mechanical Design 121, no. 3 (September 1, 1999): 424–29. http://dx.doi.org/10.1115/1.2829478.

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This paper describes the design of a unique revolute flexure joint, called a split-tube flexure, that enables (lumped compliance) compliant mechanism design with a considerably larger range-of-motion than a conventional thin beam flexure, and additionally provides significantly better multi-axis revolute joint characteristics. Conventional flexure joints utilize bending as the primary mechanism of deformation. In contrast, the split-tube flexure joint incorporates torsion as the primary mode of deformation, and contrasts the torsional properties of a thin-walled open-section member with the bending properties of that member to obtain desirable joint behavior. The development of this joint enables the development of compliant mechanisms that are quite compliant along kinematic axes, extremely stiff along structural axes, and are capable of kinematically well-behaved large motions.

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Elmandouh, A. A., and Fatimah H. Alsaad. "The Stability of Certain Motion of a Charged Gyrostat in Newtonian Force Field." Advances in Astronomy 2021 (February 22, 2021): 1–11. http://dx.doi.org/10.1155/2021/6660028.

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This work aims to study the stability of certain motions of a rigid body rotating about its fixed point and carrying a rotor that rotates with constant angular velocity about an axis parallel to one of the principal axes. This motion is presumed to take place due to the combined influence of the magnetic field and the Newtonian force field. The equations of motion are deduced, and moreover, they are expressed as a Lie–Poisson Hamilton system. The permanent rotations are calculated and interpreted mechanically. The sufficient conditions for instability are presented employing the linear approximation method. The energy-Casimir method is applied to gain sufficient conditions for stability. The regions of linear stability and Lyapunov stability are illustrated graphically for certain values of the parameters.

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Sato, Ryuta, Kentaro Nishio, Keiichi Shirase, Gianni Campatelli, and Antonio Scippa. "Influence of Motion Error of Translational and Rotary Axes onto Machined Surface Generated by Simultaneous Five-axis Motion." Procedia CIRP 14 (2014): 269–74. http://dx.doi.org/10.1016/j.procir.2014.03.067.

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Amer, T. S., and I. M. Abady. "On the motion of a gyro in the presence of a Newtonian force field and applied moments." Mathematics and Mechanics of Solids 23, no. 9 (July 18, 2017): 1263–73. http://dx.doi.org/10.1177/1081286517716734.

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This work focuses on the motion of a dynamical model that consists of a symmetric rigid body (gyro) that rotates about a fixed point similar to Lagrange’s gyroscope. This body is acted upon by external forces represented by a Newtonian force field, gyro torques about the principal axes of inertia of the gyro and perturbing moments acting on the same axes. Assuming that, the gyro initially has a high angular velocity about the dynamic axis of symmetry. The averaging technique is used to obtain a more appropriate averaging system for the governing system of equations of motion in terms of a small parameter. Therefore, the analytical solutions of this system for two applications, depending on different forms of perturbing moments, are presented. These solutions are represented graphically to clarify the effectiveness of the different parameters of the body on the motion.

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Hodge, S. J., P. Perfect, G. D. Padfield, and M. D. White. "Optimising the yaw motion cues available from a short stroke hexapod motion platform." Aeronautical Journal 119, no. 1211 (January 2015): 1–21. http://dx.doi.org/10.1017/s0001924000010228.

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AbstractThis paper presents findings from research conducted at the University of Liverpool aimed at optimising the motion cues available from a short-stroke hexapod motion platform. Piloted simulation experiments were conducted to gather both objective and subjective measures of pilot performance and motion fidelity for a typical helicopter low-speed yaw axis capture task. These measures included subjective ratings taken for the first time using a new motion fidelity rating scale. During the experiment four baseline configurations were presented to the pilot; – No motion, Rotational-only motion, Translational-only motion and Rotational + Translational motion, and within these baseline configurations various values of motion filter gains were examined. The key findings from the experiment show that the most acceptable motion fidelity was obtained when congruent cues were presented in both the rotational and translational axes. A possible explanation for this result is postulated to lie within the relative motion perception thresholds of the human semicircular canals. These results contrast with previous research which suggested that yaw axis motion cues were of less importance than translational motion cues.

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Journal articles on the topic 'Axes of motion'

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