Nonlinear Feedforward-Plus-PID Control for Electrohydraulic Steering Systems

1999 ◽  
Author(s):  
Hongchu Qiu ◽  
Qin Zhang ◽  
John F. Reid ◽  
Duqiang Wu

Abstract This paper presents the development of a nonlinear feedforward-plus-Proportional-Integral-Derivative (FPID) controller for electrohydraulic (E/H) steering on wheel-type tractors. An E/H steering system is a typical nonlinear system with deadband, saturation, asymmetric flow gain, time delay, and other nonlinear behaviors. Conventional PID controllers are incapable of achieving accurate steering control effectively on such nonlinear systems. In this research, an FPID controller was developed for effective and accurate steering control. The feedforward loop in this controller was designed to compensate for the deadband of the E/H system. The PID loop was designed to compensate the tracking error in steering control. A coordinated nonlinear gain function was designed to change the PID loop gain based on the level of the tracking error. This FPID controller has significantly improved the steering accuracy comparing with that from a PID controller. Test results showed that the maximum tracking error in steering angle was less than 0.5° corresponding to a sinusoid steering command of ±5° at the command frequency of 0.1 Hz. The maximum overshoot was less than 12% and the rise time was less than 0.25 s corresponding to a steering command of 5° step input. This FPID controller achieved effective and accurate steering control on agricultural tractor E/H steering systems.

Robotica ◽  
2001 ◽  
Vol 19 (5) ◽  
pp. 527-533 ◽  
Author(s):  
D. Wu ◽  
Q. Zhang ◽  
J. F. Reid

This paper presents an adaptive steering controller for achieving accurate and prompt steering control with noisy steering command signals and drifting valve characteristics on an automated agricultural tractor with an electrohydraulic steering system. It is difficult to accomplish performance objectives with conventional PID controllers because of the effects of disturbances and unknown factors. The adaptive controller, consisted of an adaptive gain tuner and an adaptive nonlinearity compensator, was to overcome these performance obstacles. Test results indicated that this controller provided an effective means for achieving satisfactory steering control for automated tractor traveling on changing and unpredictable farm field courses.


Author(s):  
H Qiu ◽  
Q Zhang

This paper presents the use of a feedforward-plus-proportional-integral-derivative (FPID) controller for improving the control performance of the electrohydraulic steering system on an offroad vehicle. The FPID controller used an inverse valve transform in the feedforward loop to compensate for an electrohydraulic steering system deadband and used a conventional PID feedback loop to minimize the tracking error in steering control. On-simulator evaluation tests verified that the FPID resulted in a superior steering rate tracking performance over both a feedforward controller and a PID controller. On-vehicle evaluation tests verified that this FPID controller could achieve prompt and accurate steering angle tracking for agricultural vehicle automated guidance applications.


2020 ◽  
Vol 10 (12) ◽  
pp. 4407
Author(s):  
Hyunmoo Hur ◽  
Yujeong Shin ◽  
Dahoon Ahn

In this paper, prior to the commercialization of a developed active steering bogie, we want to analyze steering performance experimentally according to steering angle level with the aim of obtaining steering performance data to derive practical design specifications for a steering system. In other words, the maximum steering performance can be obtained by controlling the steering angle at the 100% level of the target steering angle, but it is necessary to establish the practical control range in consideration of the steering system cost increase, size increase, and consumer steering performance requirements and commercialize. The steering control test using the active steering bogie was conducted in the section of the steep curve with a radius of curvature of R300, and steering performance such as bogie angle, wheel lateral force, and derailment coefficient were analyzed according to the steering angle level. As the steering angle level increased, the bogie indicated that it was aligned with the radial steering position, and steering performance such as wheel lateral force and derailment coefficient was improved. The steering control at 100% level of the target steering angle can achieve the highest performance of 83.6% reduction in wheel lateral force, but it can be reduced to about one-half of the conventional bogie at 25% level control and about one-third at 50% level. Considering cost rise by adopting the active steering system, this result can be used as a very important design indicator to compromise steering performance and cost rise issues in the design stage of the steering system from a viewpoint of commercialization. Therefore, it is expected that the results of the steering performance experiment according to the steering angle level in this paper will be used as very useful data for commercialization.


2013 ◽  
Vol 655-657 ◽  
pp. 731-734
Author(s):  
Hu Dai Fu ◽  
Zheng Zhong Wang

It is studied that a great proportion of traffic problems lies in vehicles’ steering system, and the maximum steering angle decides their steering capability and their minimum turning radius. The measuring principle of rapid measuring system, and the automatic tracking principle of measurement system have been analyzed in the paper. Also, the infrared tracking, the measuring plate positioning, the calculation of minimum turning radius, and the processing method of the test results have been described in detail. It is proved that the automatic automobile steering angle detecting system has reached the general requirements both in detection resolution and the measuring accuracy.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Cong Li ◽  
Yun-Feng Xie ◽  
Gang Wang ◽  
Su-Qi Liu ◽  
Bing Kuang ◽  
...  

This paper investigates the experimental study of differential steering control of a four-wheel independently driven (FWID) electric vehicle (EV) based on the steer-by-wire (SBW) system. As each wheel of FWID vehicle can be independently driven, differential steering is realized by applying different driven torques to the front-two wheels. Firstly, the principle of the differential steering is analyzed based on the SBW system. When the differential steering is activated, the driver’s steering request is sent to the vehicle’s ECU. Then, the ECU gives different control signals to the front-left and front-right wheels, generating an external steering force on the steering components. The external steering force pushes the steering components to turn corresponding to the driver’s request. Secondly, to test the feasibility of differential steering, a FWID EV is assembled and the vehicle is equipped with four independently driven in-wheel motors. The corresponding control system is designed. Finally, the field test of the vehicle based on the proposed differential steering control strategy is performed. In the experiment, the fixed yaw rate tracking and varied yaw rate tracking maneuvers are employed. In the fixed yaw rate tracking, the vehicle can track the desired yaw rate well with differential steering. In addition, the vehicle can track the varied yaw rate with proposed differential steering. The test results confirm the feasibility and effectiveness of the differential steering. By using the differential steering, a backup steering is established without additional components; thus, the costs can be reduced and the reliability of the vehicle steering system can be enhanced, significantly.


2009 ◽  
Vol 129 (7) ◽  
pp. 1389-1396 ◽  
Author(s):  
Misawa Kasahara ◽  
Yuki Kanai ◽  
Ryoko Shiraki ◽  
Yasuchika Mori

Author(s):  
Hui Jing ◽  
Rongrong Wang ◽  
Cong Li ◽  
Jinxiang Wang

This article investigates the differential steering-based schema to control the lateral and rollover motions of the in-wheel motor-driven electric vehicles. Generated from the different torque of the front two wheels, the differential steering control schema will be activated to function the driver’s request when the regular steering system is in failure, thus avoiding dangerous consequences for in-wheel motor electric vehicles. On the contrary, when the vehicle is approaching rollover, the torque difference between the front two wheels will be decreased rapidly, resulting in failure of differential steering. Then, the vehicle rollover characteristic is also considered in the control system to enhance the efficiency of the differential steering. In addition, to handle the low cost measurement problem of the reference of front wheel steering angle and the lateral velocity, an [Formula: see text] observer-based control schema is presented to regulate the vehicle stability and handling performance, simultaneously. Finally, the simulation is performed based on the CarSim–Simulink platform, and the results validate the effectiveness of the proposed control schema.


Author(s):  
Paul J. Pearson ◽  
David M. Bevly

This paper develops two analytical models that describe the yaw dynamics of a farm tractor and can be used to design or improve steering control algorithms for the tractor. These models are verified against empirical data. The particular dynamics described are the motions from steering angle to yaw rate. A John Deere 8420 tractor, outfitted with inertial sensors and controlled through a PC-104 form factor computer, was used for experimental validation. Conditions including different implements at varying depths, as would normally be found on a farm, were tested. This paper presents the development of the analytical models, validates them against empirical data, and gives trends on how the model parameters change for different configurations.


Author(s):  
Vahid Bahrami ◽  
Ahmad Kalhor ◽  
Mehdi Tale Masouleh

This study intends to investigate a dynamic modeling and design of controller for a planar serial chain, performing 2-DoF, in interaction with a cable-driven robot. The under study system can be used as a rehabilitation setup which is helpful for those with arm disability. The latter goal can be achieved by applying the positive tensions of the cable-driven robot which are designed based on feedback linearization approach. To this end, the system dynamics formulation is developed using Lagrange approach and then the so-called Wrench-Closure Workspace (WCW) analysis is performed. Moreover, in the feedback linearization approach, the PD and PID controllers are used as auxiliary controllers input and the stability of the system is guaranteed as a whole. From the simulation results it follows that, in the presence of bounded disturbance based on Roots Mean Square Error (RMSE) criteria, the PID controller has better performance and tracking error of the 2-DoF robot joints are improved 15.29% and 24.32%, respectively.


Author(s):  
Yaqi Dai ◽  
Jian Song ◽  
Liangyao Yu

By analyzing the key safety problems under the front-outside-tire burst steering condition, a vehicle stability control strategy is proposed in this paper, which is based on active front steering and differential braking systems. Taken both the handling stability and safety into account, we divided the whole control strategy into two layers, which are yaw moment control layer and the additional steering angle & tire force distribution layer. To solve the similar linear problem concisely, the LQR control is adopted in the yaw moment control layer. To achieve the goal of providing enough additional lateral force and yaw moment while keeping the burst tire in appropriate condition, the additional steering angle provided by active front steering system and the tire force distribution was adjusted step by step. To test the proposed control strategy performance, we modelling a basic front-outside-tire burst steering condition, in which the tire blows out once the vertical pressure reach the predefined critical value. Through simulation on different adhesion coefficient road, the control strategy proposed in this paper performance quite better compare with the uncontrolled one in aspect of movement, burst tire protection, handling stability.


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