Dual-motor Driving Servo System Research Articles

Finite-time adaptive dynamic surface synchronization control for dual-motor servo systems with backlash and time-varying uncertainties

The dual-motor driving servo system is continuously developed to satisfy strict safety and reliability requirements. However, several factors may degrade the system’s performance, such as transmission backlash, parameter drift, and motor dynamic characteristic differences. To overcome these factors, this study proposes a finite-time tracking and synchronization control method for dual-motor servo systems that suffer from backlash and time-varying uncertainties. Our solution utilizes an adaptive dynamic surface and cross-coupling control scheme to deal with tracking and synchronization control issues and compensate for the unknown time-varying uncertainties. Through synchronizing the speed and acceleration states, the proposed controller guarantees high control performance and eliminates the force fighting caused by the motor’s dynamic characteristic differences. In addition, finite-time control ensures the tracking error converges to an arbitrarily small neighborhood of zero in finite time. Moreover, the singularity problem in the derivative of the virtual control signal is avoided by introducing a new compensation term. Several simulations prove the proposed controller’s stability and effectiveness.

A Novel Adjustable Parameters PID Control of Dual-motor Driving Servo System

ABSTRACTIn order to reduce the adverse effect of backlash nonlinearity on dual-motor driving servo system, the system model is firstly described. Then a novel adjustable parameters PID control algorithm combining fuzzy RBF neural network control with PID control is proposed for the first time, and analyzed its stability. In the simulation analysis, the system track step signal, ramp signal and sine signal respectively. Simultaneously, different interference signal were applied to system output when system tracking different signal. Simulation results show that the proposed control algorithm has smaller tracking error and better anti-interference ability than that of mere PID control, because PID parameters can automatically be adjusted as the system tracking error changes. In the end, white noise interference signal are applied to system output in the experiment analysis. The experiment results also validate the higher tracking accuracy and stronger robustness of the proposed control algorithm than that of PID control.

Back‐stepping sliding mode control of one degree of freedom flight motion table

AbstractA one degree of freedom flight motion table is used to simulate the rotational movement of flying objects in hardware‐in‐the‐loop laboratories. This table uses a dual motor driving servo system. Owing to the existence of a gear transmission system, the backlash nonlinear function on modeling is inevitable, system equations are non‐affine and back‐stepping theory cannot handle this kind of system directly. Through new modeling of the backlash function as the summation of certain and uncertain parts, a proper structure for the controller algorithm is created. The controller is constructed through a back‐stepping sliding mode control algorithm. The back‐stepping concept allows the control algorithm to be extended to a high‐order dynamical system. Meanwhile, the SMC could eliminate these system uncertainties as it has a match perturbation with a virtual or real input signal of the subsystem. For non‐measurable variables, a sliding mode observer is also designed. The simulation results clearly demonstrate the superiority of the proposed method in comparison with conventional PID/FO‐PID control methods in angular tracking and speed synchronization.

Projection Algorithm-Based Dynamic Surface Control of Dual-Motor Driving Servo System with Backlash Nonlinearity

Projection Algorithm-Based Dynamic Surface Control of Dual-Motor Driving Servo System with Backlash Nonlinearity

A new adaptive control of dual-motor driving servo system with backlash nonlinearity

In order to weaken the influence of backlash nonlinearity on a dual-motor driving servo system, we first establish the state-space model of the system. We then propose a new adaptive controller combining a projection algorithm with backstepping control for the first time, to the best of our knowledge, and analyze its stability. In the simulation analysis, we respectively choose a triangular wave, sawtooth wave, and random signal as the input signal. Simulation results validate a higher tracking accuracy and stronger adaptability of the proposed control law than that of mere backstepping control. In the experimental tests, we respectively choose a step signal and sine signal and simultaneously apply a white noise signal to the system output after 3 s in each test. The test results validate a stronger adaptability and robustness than that of mere backstepping control.

All-Coefficient Adaptive Control of Dual-Motor Driving Servo System

Backlash nonlinearity and friction nonlinearity exist in dual-motor driving servo system, which reducing system response speed, steady accuracy and anti-interference ability. In order to diminish the adverse effects of backlash and friction nonlinearity to system, we proposed a new all-coefficient adaptive control method. Firstly, we introduced the dynamic model of backlash and friction nonlinearity respectively. Then on this basis, we established the characteristic model when backlash and friction nonlinearity coexist. We used recursive least square method for parameter estimation. Finally we designed the all-coefficient adaptive controller. On the basis of simplex all-coefficient adaptive controller, we designed a feedforward all-coefficient adaptive controller. The simulations of feedforward all-coefficient adaptive control and simplex all-coefficient adaptive control were compared. The results show that the former has quicker response speed, higher steady accuracy, stronger anti-interference performance and better robustness, which validating the efficacy of the proposed control strategy.

A Simple Fuzzy PI Control of Dual-Motor Driving Servo System

Aiming at the control problem of dual-motor driving servo system, in order to avoid the complicated numerical calculation of complicated control algorithm, we presented a simple fuzzy PI controller for the first time. Firstly, we explained system control principle. In view of the shortcomings of current-error negative feedback, we used speed-error negative feedback synchronous driving control strategy. Then we theoretically analyzed dual-motor synchronous driving system in detail. We proposed the conditions of dual-motor driving servo system synchronous operation for step signal and ramp signal, respectively. Finally, we presented a simple fuzzy PI controller, by combining fuzzy controller with PI controller. We analyzed the fuzzy PI control system and found it was stable. We considered two cases in simulation tests comparing fuzzy PI control with PI control. Simulation results show that fuzzy PI control has better adaptability than conventional PI control, validating the effectiveness and efficiency of the proposed control strategy.

Improved Backstepping Adaptive Control of Dual-motor Driving Servo System with Backlash Based on Fuzzy Parameter Approximation

Aiming at the control problem of dual-motor driving servo system with backlash nonlinearity, a model for the system is introduced. Two adaptive fuzzy systems were used to approximate the nonlinear part and unknown parameters in system online, to avoid the complex calculation in deducing the adaptive law of each unknown parameter. By using improved backstepping approach and recursively selecting the Lyapunov function, introducing the virtual control quantity and the integration of position tracking error, an adaptive fuzzy controller with state feedback was designed, and its stability was analyzed. System response analysis and system robustness analysis were considered in simulation test for comparing the improved backstepping control with conventional backstepping control. Simulation results show that the improved backstepping control has better position tracking performance and robustness than conventional backstepping control. Finally, experimental analysis also validates the effectiveness and efficiency of the proposed control strategy.

Eso‐Based Adaptive Robust Control of Dual Motor Driving Servo System

AbstractBased on extended state observer (ESO), we propose an adaptive robust control (ARC) for a dual motor driving servo system, in which there exist nonlinearities affecting control performance. To apply ESO and estimate the lumped uncertainty online, backlash and friction are analyzed and the nonlinear model of the plant is derived. We achieve several control objectives. First, the bias torque is considered in order to eliminate the effect of backlash. Second, the speed feedback is used to maintain the speed synchronization of motors. Then, to achieve feedforward control, finite‐time ESO is designed to estimate the unknown nonlinearities online. Furthermore, the ESO‐based adaptive robust controller is designed to guarantee L∞ of tracking error by an initialization method, maintaining the transient performance of tracking behavior. Finally, extensive experimental results on a practical test rig validate the effectiveness of our proposed method.

A Compensation Approach of Backlash Nonlinearity in Dual-Motor Driving Servo System

Aiming at the control problem of dual-motor driving servo system with backlash nonlinearity, we proposed the model of system linear part. We used describing function methods to analyze backlash nonlinearity characteristic. The simulation experiments of nonlinear system with backlash were carried out. The results of simulation show that system represents residual self-oscillation with step response, nonstationarity with low speed tracking and error abrupt change produced by sinusoidal tracking reversing. In the end, we used compensation control strategy to weaken the impact of backlash nonlinearity on dual-motor driving servo system. Finally the simulation illustrates the effectiveness of the proposed compensation control strategy.

A Compensation Approach of Dead-Zone Nonlinearity in Dual-Motor Driving Servo System

Aiming at the control problem of dual-motor driving servo system with dead-zone nonlinearity,we proposed the model of system linear part.We used describing function methods to analyze dead-zone nonlinearity characteristic.The simulation experiments of nonlinear system with dead-zone were carried out.The results of simulation show that system represents the phenomenon of zero deflection with step response,error curve exists peak at commutation time with sine response.In the end,we used compensation control strategy to weaken the impact of dead-zone nonlinearity on dual-motor driving servo system.Finally the simulation illustrates the effectiveness of the proposed compensation control strategy.