Transmission Servo Systems Research Articles

Adaptive Finite-Time Backstepping Sliding Mode Control for PMSM System With Backlash

The rapid tracking stabilization problem of the servo system with gear backlash and unmatched unknown disturbance is investigated. In this article, a novel finite-time sliding mode surface with a faster convergence rate is proposed to improve the anti-interference of the gear transmission servo system. This surface not only can adaptively and dynamically regulate the integral capability together with disturbances and tracking error variations, but also does not create singularity issues. An adaptive fixed-time reaching law (AFTRL) is proposed, which performs a faster convergence rate and chattering-free performances. The adaptive mechanism ensures the continuous property of the control output and dynamically regulates the fixed-time convergence rate regardless of initial states. The dSPACE platform is employed to validate the excellent tracking performance of the gear transmission servo system.

Adaptive control and disturbance compensation for gear transmission servo systems with large-range inertia variation

In gear transmission servo systems, backlash effect and inertia variation often generate low precision, oscillations or even affect the stability. Focusing on this issue, an adaptive terminal integral sliding mode control (ATISMC) strategy and a discrete linear extended state observer (DLESO) are proposed in this article. First, different from using traditional dynamic model, a characteristic model is established with online parameter identification to describe inertia variation. Then, a DLESO is proposed to observe and compensate the modeling error caused by parameter identification and backlash effect. An ATISMC is newly designed based on the characteristic model to suppress the uncertainties and stabilize the whole closed-loop system. Both the uniform ultimate boundedness of observation error and the practical finite-time stability of the system is proved. Finally, simulation and experimental results demonstrate that the proposed strategy can adapt to large-range inertia variation and suppress the backlash effect.

Adaptive Backstepping Compensation of Drives with Sandwiched Deadzone Nonlinearity

In this paper, a nonlinear robust adaptive controller is proposed for gear transmission servo system (GTS) containing a sandwiched deadzone due to improper gear meshing. The controller is robust to dynamic uncertainties and can compensate the effect caused by the sandwiched nonlinearity which is separated from the control input through drive compliance. The proposed design methodology does not require an adaptive inverse deadzone function and does not require the knowledge of its parameter and only the knowledge of upper bounds is required.

Adaptive Backstepping Control of Uncertain Gear Transmission Servosystems With Asymmetric Dead-Zone Nonlinearity

In this paper, an adaptive backstepping control scheme is presented to solve the position control problem for a gear transmission servosystem with unknown asymmetric sandwiched dead-zone nonlinearity. All the parameters involved in both the system and dead-zone models are allowed to be totally unknown. In contrast to the previous results where the effects of symmetric dead zone can be treated as additive disturbances in a transformed system, most of the unknown parameters of the transformed system are now time varying and dependent on the real-time value of relative displacement between the driving and driven gears. To deal with the above issue, new compensating terms in the quadratic form are introduced in the design of the virtual control signal for each recursive step. With the adaptive laws modified correspondingly, we can still show that all the closed-loop signals are ensured to be bounded and the output regulation error will converge to a compact set. Simulation results are provided to show the effectiveness of the proposed adaptive control scheme.

Adaptive terminal sliding-mode controller based on characteristic model for gear transmission servo systems

Backlash and inertia variations, which exist in gear transmission servo systems, often bring inaccuracies, oscillations or even instability. This paper presents an adaptive second-order discrete terminal sliding-mode controller (2-ADTSMC) to deal with the problem. The main contributions of this paper are as follows. First, the characteristic model of gear transmission servo system, which reduces the complexity of traditional mathematics model, is established to describe the load inertia variations. Second, the second-order discrete terminal sliding-mode control is firstly designed based on the characteristic model to restrain the backlash effect. Third, theoretical analysis proves that the quasi-sliding mode is reached in finite steps and the tracking error converges into a bounded set in finite steps. The improvement of tracking performance is verified by simulation and experimental results.

Control of Gear Transmission Servo Systems With Asymmetric Deadzone Nonlinearity

This brief deals with the output control problem of gear transmission servo systems with asymmetric deadzone nonlinearity between states. To overcome the difficulty of controller design due to the nondifferentiability of the deadzone, a brand new differentiable asymmetric deadzone model is put forward, which provides an additional design degree of freedom to approximate the real deadzone with any prescribed accuracy. Based on the differentiability of the new model, a global differential homeomorphism and a simple state feedback controller are proposed to solve the output control problem. Finally, simulation studies are included to demonstrate the main results of this brief.

Backstepping control for gear transmission servo systems with unknown partially nonsymmetric deadzone nonlinearity

This paper deals with the output tracking control of gear transmission servo (GTS) systems in the presence of deadzone nonlinearity with nonsymmetric beak points and unknown parameters. A novel differentiable deadzone model with nonsymmetric break points is put forward, which greatly facilitates the control design for a class of mechanical systems in the presence of deadzone nonlinearity. A new smooth backstepping controller, based on the newly-developed model, is proposed for the nominal system. Then, guaranteed robust steady-state performance of the closed-loop system with parametric uncertainties is derived by using Lyapunov analysis for the perturbed nonlinear systems. Simulations are carried out to validate the proposed algorithm and analysis in this paper.

Formula omitted] adaptive control of uncertain gear transmission servo systems with deadzone nonlinearity

This paper deals with the adaptive control problem of Gear Transmission Servo (GTS) systems in the presence of unknown deadzone nonlinearity and viscous friction. A global differential homeomorphism based on a novel differentiable deadzone model is proposed first. Since there exist both matched and unmatched state-dependent unknown nonlinearities, a full-state feedback L1 adaptive controller is constructed to achieve uniformly bounded transient response in addition to steady-state performance. Finally, simulation results are included to show the elimination of limit cycles, in addition to demonstrating the main results in this paper.