Energy Optimal Control Design for Steer-by-Wire Systems and Hardware-in-the-Loop Simulation Evaluation

Author(s):  
M. Selçuk Arslan ◽  
Naoto Fukushima

A Steer-By-Wire (SBW) control scheme is proposed for enhancing the lateral stability and handling capability of a super lightweight vehicle by using the energy optimal control method. Tire dissipation power and virtual power, which is the product of yaw moment and the deviation of actual yaw rate from the target yaw rate, were selected as performance measures to be minimized. The SBW control scheme was tested using Hardware-In-the-Loop (HIL) simulation on an SBW test rig. The case studies performed were high-speed rapid lane change, crosswind, and braking-in-a-turn. HIL simulation results showed that the SBW control scheme was able to maintain vehicle stability. The proposed SBW control design taking advantage of the full range steering of front wheel, significantly improves the vehicle handling capability. The results also demonstrate the importance of SBW control for super lightweight vehicles.

2021 ◽  
pp. 002029402110354
Author(s):  
Yifeng Zhang ◽  
Zhiwen Wang ◽  
Yuhang Wang ◽  
Canlong Zhang ◽  
Biao Zhao

In order to improve the handling stability of four-wheel steering (4WS) cars, a two-degree-of-freedom 4WS vehicle dynamics model is constructed here, and the motion differential equation of the system model is established. Based on the quadratic optimal control theory, the optimal control of 4WS system is proposed in this paper. When running at low speed and high speed, through yaw rate feedback control, state feedback control, and optimal control, the 4WS cars are controlled based on yaw rate and centroid cornering angle with MATLAB/Simulink simulation. The result indicates that 4WS control based on the optimal control can improve the displacement of the cars. And, the optimal control of 4WS proposed in this paper can eliminate centroid cornering angle completely compared with other two traditional optimal control methods. Besides, the optimal control enjoys faster response speed and no overshoot happens. In conclusion, the optimal control method proposed in the paper represents better stability, moving track and stability, thereby further enhancing the handling property of cars.


Author(s):  
Satoru Ito ◽  
Yuji Suzuki

Optimal control scheme for transient temperature profile inside electronic devices such as pulsed laser diode is developed based on the adjoint equation of one-dimensional heat conduction. Joule heating with a thin-film heater is employed as the control input in order to minimize temperature changes of a thin active layer embedded in a modeled laser diode. In numerical simulations assuming the light-emitting time period of 1 μs, temperature variation of the active layer is successfully suppressed by 80% with the heat input prior to the onset of the laser pulse. It is found that the Fourier number of the layer between the control heater and the active layer is the key parameter to minimize the temperature fluctuations. We also successfully demonstrate suppression of the temperature change in a MEMS-based experimental setup.


2010 ◽  
Vol 118-120 ◽  
pp. 728-732
Author(s):  
Shu Wen Zhou ◽  
Si Qi Zhang ◽  
Guang Yao Zhao

Tractor semitrailers on high speed obstacle avoidance under emergency are likely to arise rollover or jack-knifing, which are serious risks for motorists. A dynamic stability analysis model of a three-axle tractor semitrailer vehicle is developed using the application tool. The linearized vehicle model is utilized to predict the dynamics state of the tractor semitrailer built in multibody dynamics simulation software. The lateral stability simulation for yaw rate following and anti-rollover has been performed on the dynamic model based on virtual prototyping. The results show that the lateral stability control based on tractor semitrailer proposed in this paper can stabilize the tractor semitrailer, rollover and jack-knifing can be prevented to a large extent.


2017 ◽  
Vol 14 (01) ◽  
pp. 1650031 ◽  
Author(s):  
Wenjun Ye ◽  
Zhijun Li ◽  
Chenguang Yang ◽  
Fei Chen ◽  
Chun-Yi Su

The paper studies the control design of an exoskeleton robot based on electromyography (EMG). An EMG-based motion detection method is proposed to trigger the rehabilitation assistance according to user intention. An adaptive control scheme that compensates for the exoskeleton's dynamics is employed, and it is able to provide assistance tailored to the human user, who is supposed to participate actively in the training process. The experiment results verify the effectiveness of the control method developed in this paper.


1995 ◽  
Vol 117 (4) ◽  
pp. 503-512 ◽  
Author(s):  
Sudhendu Rai ◽  
Haruhiko Asada

This paper presents the integrated structure/control design of high speed single link robots based on time-optimal control and finite element analysis. First, the solutions of a time optimal control problem are analyzed with respect to the arm link inertia and its structural flexibility. A new technique is developed to further reduce the optimal traveling time by redesigning the arm structure through the trade-off analysis between the arm inertia and its natural frequency. In the latter half of the paper, the design criterion is extended to multiple indices by considering residual vibrations, load bearing capacity and other design constraints. For suppressing residual vibrations, a simple feedback control is designed and its dynamic performance with respect to pole-zero locations is improved along with other criteria through mechanical structure modification. The finite element method is used as a modeling tool and the shape of the arm geometry is modified as design parameters. An arm is designed which performs much better as compared to the design which is done without considering the interactions between physical structure and control. The newly designed arm is tested by constructing an experimental setup. The results show significantly improved performance.


Author(s):  
Atsushi Oshima ◽  
Xu Chen ◽  
Sumio Sugita ◽  
Masayoshi Tomizuka

Variable-gear-ratio steering is an advanced feature in automotive vehicles. As the name suggest, it changes the steering gear ratio depending on the speed of the vehicle. This feature can simplify steering for the driver, which leads to various advantages, such as improved vehicle comfort, stability, and safety. One serious problem, however, is that the variable-gear-ratio system generates unnatural torque to the driver whenever the variable-gear-ratio control is activated. Such unnatural torque includes both low-frequency and steering-speed-dependent components. This paper proposes a control method to cancel this unnatural torque. We address the problem by using a tire sensor and a set of feedback and feedforward algorithms. Effectiveness of the proposed method is experimentally verified using a hardware-in-the-loop experimental setup. Stability and robustness under model uncertainties are evaluated.


Author(s):  
William S. Oates ◽  
Phillip G. Evans ◽  
Ralph C. Smith ◽  
Marcelo J. Dapino

A hybrid nonlinear optimal control design is experimentally implemented on a magnetostrictive Terfenol-D actuator to illustrate enhanced tracking control at relatively high speed. The control design employs a homogenized energy model to quantify rate-dependent nonlinear and hysteretic ferromagnetic switching behavior. The homogenized energy model is incorporated into a finite-dimensional nonlinear optimal control design to directly compensate for the nonlinear and hysteretic magnetostrictive constitutive behavior of the Terfenol-D actuator. Additionally, robustness to operating uncertainties is addressed by incorporating proportional-integral (PI) perturbation feedback around the optimal open loop response. Experimental results illustrate significant improvements in tracking control in comparison to PI control. Accurate displacement tracking is achieved for sinusoidal reference displacements at frequencies up to 1 kHz using the hybrid nonlinear control design, whereas tracking errors become significant for the PI controller for frequencies equal to or greater than 500 Hz.


1996 ◽  
Vol 118 (4) ◽  
pp. 721-726 ◽  
Author(s):  
Cheol-Soon Kim ◽  
Chong-Won Lee

As a new rotor control scheme, isotropic control of weakly anisotropic rotor bearing system in complex state space is proposed, which utilizes the concepts on the eigenstructure of the isotropic rotor system. Advantages of the scheme are that the controlled system always retains isotropic eigenstructure, leading to circular whirling due to unbalance and that it is efficient for control of unbalance response. And the system analysis and controller design becomes simple and yet comprehensive since the order of the matrices treated in the complex domain approach is half of that in the real approach. The control scheme is applied to a rigid rotor-active magnetic bearing system which is digitally controlled and the control performance is investigated experimentally in relation to unbalance response and control energy. It is found that the isotropic optimal control method, which essentially eliminates the backward unbalance response component, is more efficient than the conventional optimal control in that it gives smaller major whirl radius and yet it often requires less control effort.


SIMULATION ◽  
2019 ◽  
Vol 96 (2) ◽  
pp. 169-183
Author(s):  
Saumya R Sahoo ◽  
Shital S Chiddarwar

Omnidirectional robots offer better maneuverability and a greater degree of freedom over conventional wheel mobile robots. However, the design of their control system remains a challenge. In this study, a real-time simulation system is used to design and develop a hardware-in-the-loop (HIL) simulation platform for an omnidirectional mobile robot using bond graphs and a flatness-based controller. The control input from the simulation model is transferred to the robot hardware through an Arduino microcontroller input board. For feedback to the simulation model, a Kinect-based vision system is used. The developed controller, the Kinect-based vision system, and the HIL configuration are validated in the HIL simulation-based environment. The results confirm that the proposed HIL system can be an efficient tool for verifying the performance of the hardware and simulation designs of flatness-based control systems for omnidirectional mobile robots.


Sign in / Sign up

Export Citation Format

Share Document