Yaw Motion Research Articles

Motion Trajectory-Based Transportation Control for 3-D Boom Cranes: Analysis, Design, and Experiments

Boom crane systems with high practicality, the control problems of which are more complex than those of most other underactuated systems due to their strongly nonlinear dynamical coupling characteristics, are widely applied in various places. In addition to the basic control objectives of accurate boom positioning and payload swing suppression, another challenging aspect is how to improve the transient performance of the state variables while ensuring time (sub)optimality during transportation. In this paper, to address the two aforementioned issues, i.e., complicated nonlinear dynamics and ensuring transient performance, a new nonlinear time suboptimal trajectory planning approach, which does not require linearizing the original nonlinear dynamics, is proposed to achieve efficient control results for the boom crane system. After performing an in-depth analysis, we find a transformation relationship between four tip signals and the state variables. Then, by planning proper trajectories for the tip signals based on the original nonlinear boom crane dynamics, we obtain swing-free time suboptimal trajectories for the boom pitch and yaw movements; hence, the boom can reach its destination accurately, and the payload swing can be suppressed. Moreover, the state variables can be restricted within specified ranges as required. The presented trajectory planner can be considered as the first solution for generating trajectories for the boom crane system, respecting various state constraints without the need for any linearization operations. Finally, some hardware experiments are introduced to verify the effectiveness of the presented control strategy.

Oscillatory Yaw Motion Control for Hydraulic Power Steering Articulated Vehicles Considering the Influence of Varying Bulk Modulus

In this investigation, a detailed hydraulic steering system of articulated steer vehicles (ASVs) and a 12-DOF ASV model are developed for vehicle dynamics performance research. The real-time changing characteristic of oil bulk modulus is considered. Field test and multibody dynamics model by Adams/View software are compared with the established mathematical model, respectively, to verify the correctness of the model at low speed and high speed. The snaking and oscillatory area is confirmed to reveal the influence of varying bulk modulus on the stability of ASV. To improve the stability of ASV, the direct yaw moment control system and driving force distribution system are designed with the application of the optimal control theory. The upper level controller calculates the expected yaw moment by feedforward and feedback compensatory strategies. Different from zero-sideslip control in most studies, an Ackermann-based sideslip angle is used for feedforward compensatory gain derivation and reference model design. The lower level controller distributes the driving force for each wheel aiming at the optimal utilization rate of tires. High-speed weave test by sinusoidally steering for loaded ASV is simulated to verify the effectiveness of the control algorithms.

Wireless Multifrequency Feature Set to Simplify Human 3-D Pose Estimation

We present a multifrequency feature set to detect driver's three-dimensional (3-D) head and torso movements from fluctuations in the radio frequency channel due to body movements. Current features used for movement detection are based on the time-of-flight, received signal strength, and channel state information and come with the limitations of coarse tracking, sensitivity toward multipath effects, and handling corrupted phase data, respectively. There is no standalone feature set that accurately detects small and large movements and determines the direction in 3-D space. We resolve this problem by using two radio signals at widely separated frequencies in a monostatic configuration. By combining information about displacement, velocity, and direction of movements derived from the Doppler effect at each frequency, we expand the number of existing features. We separate pitch, roll, and yaw movements of head from torso and arm. The extracted feature set is used to train a K-Nearest Neighbor classification algorithm, which could provide behavioral awareness to cars while being less invasive as compared to camera-based systems. The training results on data from four participants reveal that the classification accuracy is 77.4% at 1.8 GHz, it is 87.4% at 30 GHz, and multifrequency feature set improves the accuracy to 92%.

Proposal of a compact magnetically levitated transverse flux permanent magnet linear synchronous motor as a 6‐DOF transport carrier

In this study, a novel 6-degree of freedom compact carrier using magnetically levitated transverse flux permanent magnet linear synchronous motor is proposed and initial design characteristics are analysed. Motor structure is compact with magnetic iron cores for thrust and levitation, arranged orthogonally. This allows reduced magnetic coupling between linear synchronous motor (LSM) and electromagnets despite their close proximity. Such configuration also ensures independent design for propulsion and suspension. Furthermore, by virtue of the proposed configuration, yaw and lateral motion are inherently stable, leaving the required active actuators to merely four for thrust, pitch, roll, and heave active control. Preliminary characteristics are analysed using 3D finite element method and performance considerations for the simultaneous design of LSM and electromagnets are discussed thoroughly.

Robust Control in Diagonal Move Steer Mode and Experiment on an X-by-Wire UGV

This paper proposes a novel X-by-wire unmanned ground vehicle (UGV)-unmanned ground carrier (UGC). To show functions of the UGV, the mechanisms and design processes of the key subsystems are described, especially the in-wheel motor-driven and independent steer subsystems. As an all-wheel-independently steered (AWIS) UGV, the UGC is able to achieve the diagonal move steer mode (DMSM) to improve the maneuverability significantly. To improve the path tracking performance in DMSM, a robust H2/H∞ chassis yaw controller is proposed, which uses the additional yaw moment provided by in-wheel motors to track the desired sideslip angle and avoid the yaw motion. The energy to peak and energy to energy performance of the sideslip angle and the yaw velocity are considered and handled by linear matrix inequalities (LMIs) approach during the H2/H∞ controller design. The parametric uncertainties and disturbances of the vehicle mass, the yaw inertia, and tire cornering stiffness are considered to improve the robustness. Finally, the step steer and lane change tests are conducted with the UGV testbed to validate the efficiency and robustness of the proposed chassis controller.

Integrated yaw and rollover stability control of an off-road vehicle with mechanical elastic wheel

An integrated control algorithm of the differential braking and the active suspension to improve yaw and rollover stability of vehicles with mechanical elastic wheel (ME-Wheel) is developed. By simplifying the structure of ME-Wheel, a fitting tire model named brush model is constructed. Then, a nonlinear 8-DOF vehicle model with ME-Wheel is built up for rollover prevention, which utilizes a predictive load transfer ratio (PLTR) as the rollover index and a Kalman filter is used to eliminate the measurement noise. In order to design an integrated control algorithm, fuzzy proportional-integral-derivative (PID) methodology is adopted by simultaneous control of the yaw and roll motions. The proposed algorithm, based on the idea that makes yaw stability controller and roll stability controller work independently first, then unifies by way of weight according to fuzz control, after that, brake force distributor selects single efficient braking wheel to achieve yaw moment and one of the front braking wheels with varying brake pressure to achieve the desired brake torque and the wheel slip regulator is designed with sliding mode control technique to prevent the wheels from locking; and the active suspension system alters the stiffness of the active suspension to prevent rollover. Simulation results show that the integrated yaw and rollover stability control system could improve the handing stability of vehicle under the limit driving conditions, and prevent rollover happening.

Study of parametric roll in oblique waves using a three-dimensional hybrid panel method

A reliable numerical tool for the prediction of the parametric roll is important in the development of the second generation intact stability criteria. The main difficulty of the prediction of the parametric roll comes from the significant coupling of the roll with other motions, especially the heave and pitch motions. In this paper, the numerical method for determining the parametric roll is studied and the results are benchmarked against the model test data. Firstly, a 3 degrees-of-freedom (DOF) time domain hybrid panel method is validated by experimental data in regular oblique waves and irregular head waves. Secondly, the verified 3DOF method is extended to a fully coupled 6DOF method with the course control. Finally, taking the C11 containership as the test case, the parametric roll in oblique waves is computed, and the effects of the surge, sway and yaw motions on the parametric roll are evaluated with the developed mathematical models. The results show that the effects of the surge and sway motions on the parametric roll is insignificant, while the effects of the yaw motion are more notable. The results of the roll amplitudes and the standard deviation of the roll angles show that the model based on 3DOF gives relatively conservative results, and can be directly used for the stability assessment of the parametric roll.

Horizontal Backward Launch Dynamics Modeling and Analysis

Fighters’ air strikes play a vital role in modern warfare. But, with the development of fighters, the amount of bombs will inevitably become a major disadvantage due to the limitations of the invisible design and other functions, so a combination of the old model bombers and the advanced fifth-generation fighters has been proposed. This paper takes the aircraft missile horizontal backward launch system as the research object; firstly, the finite element model of the missile’s off-track is established, and the simulation calculation under the fixed platform is tested to verify the correctness of the finite element model. Meanwhile, the simulation parameters of the initial trajectory are obtained. Then, by establishing the separation model of the machine under the open state of the aircraft’s rear launcher, the variation of the flow field during the separation process of the missile is analyzed, and the variation of the force and the attitude of the missile is studied. It is found that the pitching motion of the missile is greatly affected by the initial pitch angle, it is always in the heading state during the whole separation process, and the yaw motion is not obvious.

A real time wear measurement system for tripod type constant velocity joints

A real-time wear measurement system for tripod type Constant Velocity (CV) joints is proposed in this study. Adhesive wear on tripod type CV joints is very crucial to the life time of CV joints but it is very difficult to measure the wear depth of a tripod type CV joint separate from the drive shaft assembly. The wear measurement system developed in this study can measure the wear depth of a tripod type CV joint in real-time as it applies kinematics and forces to the CV joint.In order to apply the same motions as the motions of an actual CV joint, kinematics of the CV joint has been analyzed. As a result, reciprocating stroke and yaw motions have been completely implemented in the system. The wear measurement system comprises four parts. The first part is for applying normal forces to a set of spherical roller and housing track. One servo motor, spur gear and ball screw sets were employed to generate and augment the normal forces. The second and third parts are for applying reciprocating stroke and yaw motions, respectively. These parts synchronize with each other to make the same motion profiles as the actual CV joint. The fourth part is for measurement. This part consists of load cell and rotary encoder to measure the surge normal forces caused by the flaking phenomena and the wear depth caused by the adhesive wear. In the case of the encoder, the wear depth is augmented by the ball screw and spur gear sets so 0.18°/μm of measurement resolution can be achieved.For the validation of the system, a tripod type CV joint was selected, and its wear depth was measured by the system and the results were compared with the wear depth measured by a profilometer.

Oblique-Asymmetric 2D+T Model to Compute Hydrodynamic Forces and Moments in Coupled Sway, Roll, and Yaw Motions of Planing Hulls

In the present article, it has been tried to compute hydrodynamic forces and moments in coupled sway, roll, and yaw motions of planing hulls. For this purpose, wedge water entry has been considered in its generalized form with vertical, horizontal, and roll velocities. Using potential theory, new added mass formulas for coupled sway, roll, and yaw motion of planing hulls have been derived. Moreover, by introducing oblique-asymmetric 2D+T model and implementing momentum theory, sway force, roll moment, and yaw moment have been computed. The obtained hydrodynamic forces and moments have been compared against experimental results and previous empirical method. It has been observed that the method is accompanied with large errors and under-prediction, in the cases with zero and negative roll angle, especially at a yaw angle of 15°, which is a related limitation of the method. Better accuracy in prediction of sway force and yawing moment is observed at a trim angle of 6° and roll angles of 10° and 20°, especially for small yaw angles. The main sources of errors are found to be as follows. 1) Flow separation from the wedge apex in negative roll angle at large yaw angles, which results in under-prediction of sway force, rolling moment, and yawing moment 2) Tendency of the flow to move from starboard to port at a trim angle of 6° for the vessel with a deadrise angle of 30° at a negative roll angle and yaw angle of 15°, which cannot be simulated by the current method. 3) Reduction of contribution of hydrostatic pressure at a speed coefficient of 4.0, which is not well modeled by the proposed method and results in under-prediction of rolling moment. 4) Overprediction of center of pressure at a yaw angle of 10° and 15°, which results in under-prediction of yawing moment. 5) Prediction of nonzero values for chine wetted length at roll angles of 10° and 20° for the yawed vessel at a trim angle of 6°, which results in under-prediction of rolling moment. 6) Over-prediction of starboard wetted length at negative roll angle at a trim angle of 6°.

Semi-active Control to Reduce Lateral Vibration of Passenger Rail Vehicle Using Disturbance Rejection and Continuous State Damper Controllers

In this paper, Bouc–Wen type magnetorheological fluid damper has been used to monitor the ride quality of a prevailing rail vehicle in lateral vibrations. Modelling of the rail vehicle is done in such a manner that it has an entire 9 degrees of freedom by significant considerations of lateral, roll and yaw motions of the car body, rear, and the front chassis. 200 km/h is considered as train speed for tracks with two varying disturbances. A system consisting of multibody in VI-rail software is provided by a track input and ergo, wheel response it obtained. SIMULINK (software) is responsible for the representation of the motions of the wheel as mathematical models. Two different types of analysis are done firstly with conventional passive lateral damper and secondly with semi-active MR lateral damper in subordinate suspension. To diminish lateral vibrations, the disturbance refusal and non-stop state controller algorithms were executed to manage the damper force. Results acquired are in the form of acceleration and displacement of the center of mass of the body under consideration is done by comparing in terms of reduction indices of their vibrations. A significant improvement in the index is seen in which a semi-active lateral damper is mounted. The results show that the proposed system significantly improves both, the vibration attenuation ability and the ride quality of the vehicle.

A study of hand-movement gestures to substitute for mouse-cursor placement using an inertial sensor

Abstract. This paper examines the new study of hand orientation as a substitute for computer-mouse movement and is evaluated based on ISO/TS 9241 part 411: Ergonomics of human–system interaction-evaluation methods for the design of physical input devices. Two pairs of hand-orientation candidates were evaluated, using, for example, pitch–roll and pitch–yaw to substitute for up–down and left–right mouse-cursor movements. The up–down cursor movement was generated from the pitch orientation, while the left–right cursor movement was generated from the roll or yaw orientation, depending on the evaluation of the proposed gesture. The research employed a standard computer mouse as a baseline comparison for the study. The empirical study was conducted to evaluate quantitative performance such as throughput and movement time. The best impression resulted when the throughput had the greatest value as well as the shortest movement time. The performance test was based on Fitts's law using a multi-directional tapping test as suggested by ISO/TS 9241-411. The test was divided into several levels of difficulty, including high, medium, low, and very low. The other assessment is qualitative and was performed using the comfort-rating scale questionnaire and rating of perceived exertion of comfortability and fatigue. The quantitative results show that pitch–yaw throughput is slightly higher than for the pitch–roll gesture, and that the movement time in pitch–yaw is slightly less than in pitch–roll, although there is no statistically significant difference between the two. We also found that pitch–yaw movements have a higher level of comfort based on the comfort-rating scale test. Since the test was divided into levels of difficulty, we identified those gestures suitable for the task with a low and very low level of difficulty based on throughput, movement time, and error-rate results. Finally, this study suggests that pitch–roll and pitch–yaw movements of the hand can be used as substitutes for the mouse, and that pitch–yaw movements are superior in regard to causing less fatigue than pitch–roll movements. Furthermore, this study provides a new suggestion for a suitable level of difficulty when using an inertial sensor as an emulator for the movement of a mouse cursor in the field of human–computer interaction.

Experimental test of vision-based navigation and system identification of an unmanned underwater survey vehicle (SAGA) for the yaw motion

In this study, a nonlinear mathematical model for an unmanned underwater survey vehicle (SAGA) is obtained. The structure of the mathematical model of the vehicle comes from a Newton–Euler formulation. The yaw motion is realized by a suitable combination of right and left thrusters. The navigation problem is solved by using the inertial navigation system and vision-based measurements together. These are integrated to more accurately obtain navigation data for the vehicle. In addition, the magnetic compass is used to support the attitude information of the vehicle. A pool experimental set-up is designed to test the navigation system. Performance of the resultant navigation system can be analysed by creating suitable system state, measurement and noise models. The navigational data for the vehicle has been improved using a Kalman filter. The mathematical model of the vehicle includes some unknown parameters such as added mass and damping coefficients. It is not possible to determine all the parameter values as their effects on the state of the system are usually negligible. On the other hand, most of the ‘important’ parameters are obtained based on a system identification study of the vehicle using this estimated navigational data for coupled motion. This study is performed in a MATLAB/Simulink environment.

Inspired by Human Eye: Vestibular Ocular Reflex Based Gimbal Camera Movement to Minimize Viewpoint Changes

Human eyeballs move relative to the head, resulting in optimal changes in the viewpoint. We tested similar vestibular ocular reflex (VOR)-based movement on Zenmuse-X3 gimbal camera relative to pre-defined YAW movements of the DJI Matrice-100 unmanned aerial vehicle (UAV). Changes in viewpoint have various consequences for visual and graphical rendering. Therefore, this study investigated how to minimize these changes. OpenGL visualization was performed to simulate and measure viewpoint changes using the proposed VOR-based eyeball movement algorithm and compared with results of VOR based gimbal movement. The gimbal camera was setup to render images (scenes) on flat monitors. Positions of pre-fixed targets in the images were used to measure the viewpoint changes. The proposed approach could successfully control and significantly reduce the viewpoint changes and stabilize the image to improve visual tracking of targets on flat monitors. The proposed method can also be used to render real-time camera feed to a head-mounted display (HMD) in an ergonomically pleasing way.

Double-Diffracted Spatially Separated Heterodyne Grating Interferometer and Analysis on its Alignment Tolerance

An optical configuration of double-diffracted spatially separated heterodyne grating interferometer with a mechanical fixture was designed. To further investigate its features and provide robust measurements, the alignment tolerance in double-diffracted spatially separated heterodyne grating interferometer was qualitatively and quantitatively analyzed. Except for the offset error causing no influence on the interfering signal, the effect of the other four errors, roll, yaw, pitch angles, and stand-off error were geometrically analyzed and mathematically modeled. The simulation result quantified the position mismatches of output beams in a double-diffracted configuration and found the crucial structural parameters related to the intensity of interfering signals. Experiments based on the grating interferometer with a mechanical fixture and the same optical configuration built by independent optical components were implemented, whose results agreed with the simulation. Besides, the results showed that the proposed grating interferometer structure could tolerate the ±1100 arcsec roll movement, ±440 arcsec yaw movement, ±280 arcsec pitch movement, and ±0.6 mm stand-off error when -10 dB intensity loss is afforded.

Rollover prevention for a heavy vehicle using optimised slide mode steering control

For a heavy vehicle, active steering can effectively prevent rollover, however, it also changes the operation of the vehicle away from the driver's intentions. To improve rollover stability and reduce tracking error, an optimised slide mode steering control strategy is proposed. Four degrees of freedom linear model is used, which includes lateral, yaw, and roll motions of the sprung mass and unsprung mass. This model is also validated to describe heavy vehicle rollover dynamics. From the model, slide mode control based roll angle and lateral displacement strategies are developed, respectively, and the optimised slide mode steering control strategy is presented to track the set routes and prevent vehicle rollover. Furthermore, some typical numerical cases are simulated to demonstrate the effectiveness of the control strategies. The results show that the optimised strategy can effectively prevent vehicle rollover and significantly improve the performance of tracking the driver's intention for a heavy vehicle.

Adaptive tracking control based on neural approximation for the yaw motion of a small-scale unmanned helicopter

This article aims to study a solution that can solve the problem of tracking control for yaw motion of an unmanned helicopter. The non-affine nonlinear equation is converted to a simplified affine model. The unknown parameters are estimated by the Levenberg–Marquardt algorithm. An autonomous flight controller is developed with the Lyapunov-based adaptive controller for a discrete-time system. For flight data collection and verification purpose, the software-in-the-loop is constructed based on Simulink and X-Plane simulator. The designed system is applied in the control of the yaw motion of an R30 V2 helicopter under ideal and turbulent environments. The performance of the proposed method is compared with the fuzzy logic controller, and the simulation results show that the quality of the current approach is considerably better.

Steering Controller Design for Smart Autonomous Surface Vessel Based on CSF L2 Gain Robust Strategy

During the mission at sea, the yaw motion of the smart autonomous surface vessel (SASV) is always subject to the external disturbances. These issues make the design of a robust controller for steering autopilot system a quite challenging task. This paper focuses on the utilization of closed-loop shaping filter (CSF) to improve the SASV steering L2 gain robust control scheme. First, the mathematical model of the SASV is proposed and the parameters of the SASV model are obtained by the recursive least squares method (RLSM) based on the SASV turning test. Then the CSF L2 gain nonlinear robust controller design for SASV steering autopilot is described, and the stability and robustness of the proposed controller are proved based on the Lyapunov synthesis. Finally, the strong robustness and superior control performance are demonstrated through the practical SASV experiments. At the same time, the concise controller structure and definite physical meaning of SASV controller parameters are also concluded.

Ship Steering Control Based on Quantum Neural Network

During the mission at sea, the ship steering control to yaw motions of the intelligent autonomous surface vessel (IASV) is a very challenging task. In this paper, a quantum neural network (QNN) which takes the advantages of learning capabilities and fast learning rate is proposed to act as the foundation feedback control hierarchy module of the IASV planning and control strategy. The numeric simulations had shown that the QNN steering controller could improve the learning rate performance significantly comparing with the conventional neural networks. Furthermore, the numeric and practical steering control experiment of the IASV BAICHUAN has shown a good control performance similar to the conventional PID steering controller and it confirms the feasibility of the QNN steering controller of IASV planning and control engineering applications in the future.

Direct yaw control based on a phase plan decomposition for enhanced vehicle stability

This paper introduces an advanced direct yaw control (DYC) by supervision with the aim of improving the safety of vehicles. The proposed DYC is based on a hierarchical approach and a global stabilizing yaw moment is calculated by combining two different controllers in order to control yaw rate and vehicle sideslip angle. The activation of each controller depends on the critical driving situation detected by the proposed supervisor. The latter is based on a yaw rate - sideslip angle phase plan decomposition by using the limits of the yaw motion variables. Finally, the global stabilizing yaw moment will be distributed on the four wheels through the control allocation by using differential braking.