Stability control of steer by wire system based on improved ADRC

In this paper, a stability control method based on active front steering control is proposed to steer by wire system (SBW). The proposed control system consists of an inner-loop angle tracking controller and an outer-loop controller. The inner-loop controller contributes to front steering angle tracking, and it is designed by PID control. The outer-loop controller restrains the effect of disturbance by feeding a compensation steering angle, and it is designed by using Improved Active Disturbances Rejection Control (IADRC) with less adjusted parameters than Active Disturbances Rejection Control (ADRC). Finally, the effectiveness of the proposed method is evaluated via numerical simulation and vehicle test. The obtained results show that the proposed controller can improve the handling stability of the SBW system. To a certain extent, the study results promote the research and application of SBW system.

PID Tuning Method Using Chaotic Safe Experimentation Dynamics Algorithm for Elastic Joint Manipulator

This paper proposed the chaotic safe experimentation dynamics algorithm (CSEDA) to regulate angular tracking and vibration of the self-tuning PID controller for elastic joint manipulators. CSEDA was a modified version of the safe experimentation dynamics algorithm (SEDA) that used a chaos function in the updated equation. The chaos function increased the exploration capability, thus improving the convergence accuracy. In this study, two self-tuning PID controllers were used to regulate the rotating angle tracking and vibration for elastic joint manipulators in this control challenge. The suggested self-tuning PID controller's performance was evaluated in angular motion trajectory tracking, vibration suppression, and the pre-determined control fitness function. A self-tuned PID controller based on CSEDA could achieve superior control accuracy than a traditional SEDA and its variants.

Robust command filtered control for course tracking of ships under actuator dynamics with input magnitude and rate saturation

This article investigates the course tracking of ships subject to parametric uncertainties and environmental disturbances. Particularly, the actuator dynamics with input magnitude and rate saturation is also considered. When including the actuator dynamics, the ship course tracking system becomes a mismatching system, which brings a great difficulty to the control design. A novel robust command filtered control strategy is presented by incorporating a disturbance observer and an auxiliary anti-saturation system into the command filtered backstepping control architecture. The disturbance observer is designed to compensate for the mismatched lumped disturbance. The auxiliary anti-saturation system is introduced to tackle the effects of input magnitude and rate saturation. It is strictly proved that all the closed-loop error signals under the proposed controller are uniformly ultimately bounded and the course angle tracking error can converge to the adjustable small region around the origin. Moreover, the proposed controller is computationally simple and has the strong robustness against uncertainties and disturbances. The effectiveness and advantages of the proposed control strategy are verified through simulations and comparisons.

Accuracy Improvement in Resolver Offset Detection Based on Angle Tracking Observer with Coordinate Transformation

It is necessary to obtain the rotor position of the Interior Permanent Magnet Synchronous Motor (IPMSM) for instantaneous torque control in an electric vehicle system. A resolver is mostly used as a rotor position sensor, each motor has a resolver offset according to the fit tolerance of the resolver pressed into the rotor shaft when the motor is manufactured. This resolver offset is having a huge effect on IPMSM output characteristics. Therefore, resolver offset detection equipment with a method for high precision of detection is required in production lines in order to make uniform characteristics of IPMSM. It is also necessary to have robust performance in many different kinds of the noise of equipment in the production line. This paper presents a highly precise Resolver to Digital Converter (RDC) that is implemented with LabVIEW of National Instruments and a resolver offset detecting method that has the robust performance to noise based on coordinate transformation algorithm. Experiments with and without the proposed method were performed and a comparative analysis is conducted to test the validity.