Showing papers by "Ye-Hwa Chen published in 2022"
TL;DR: In this article , a new robust control design for high-speed Permanent Magnet Synchronous Motor (PMSM) is proposed based on a novel performance measure β^, which is introduced as a dynamic depiction of the constraint-following error.
Abstract: High-speed Permanent Magnet Synchronous Motor (PMSM) systems have been widely used in industry and other fields for their advantages of having a simple structure, low processing cost and high efficiency. At present, the control precision of PMSM is required to be higher and higher, but it faces two major challenges. The first is that the PMSM system possesses (possibly fast) time-varying uncertainty. The second is that there exist nonlinear portions in the PMSM system, such as nonlinear elasticity, etc. To resolve these challenges, a novel performance measure β^ is introduced as a dynamic depiction of the constraint-following error, and a new robust control design is proposed based on β^. While this control renders guaranteed performance regardless of uncertainty, an optimal design of a control parameter is further pursued. This inquiry is summed up as a semi-infinite constrained optimization problem. After the induction of the necessary condition, the candidate solutions can be identified. These are further screened by a sufficient condition, which results in the actual solution. To verify the effectiveness of the control design, the compressor powered by a super high-speed PMSM system is simulated, and its performance is discussed.
5 citations
TL;DR: In this paper , an adaptive robust formation control scheme for the connected and autonomous vehicle (CAV) swarm system by utilizing swarm property, diffeomorphism transformation, and constraint following is proposed.
Abstract: This article proposes an adaptive robust formation control scheme for the connected and autonomous vehicle (CAV) swarm system by utilizing swarm property, diffeomorphism transformation, and constraint following. The control design is processed by starting from a 2-D dynamics model with (possibly fast) time varying but bounded uncertainty. The uncertainty bounds are unknown. For compact formation, the CAV system is treated as an artificial swarm system, for which the ideal swarm performance is taken as a desired constraint. By this, formation control is converted into a problem of constraint following and then a performance measure $\beta $ is defined as the control object to evaluate the constraint following error. For collision avoidance, a diffeomorphism transformation on space measure between two vehicles is creatively performed, by which the space measure is positive restricted. For uncertainty handling, an adaptive robust control scheme is proposed to render the $\beta $ -measure to be uniformly bounded and uniformly ultimately bounded, that is, drive the controlled (CAV) swarm system to follow the desired constraint approximatively. As a result, the system can achieve the ideal swarm performance; thereout, compact formation is realized, regardless of the uncertainty. The main contribution of this article is exploring a 2-D formation control scheme for (CAV) swarm system under the consideration of collision avoidance and time-varying uncertainty.
5 citations
TL;DR: In this article , the authors proposed a robust control method to reduce the trajectory tracking errors of the SCARA robot with uncertainties including parameters such as uncertainty of the mechanical system and external disturbance, which are time-varying and nonlinear.
Abstract: In this paper, we design a novel robust control method to reduce the trajectory tracking errors of the SCARA robot with uncertainties including parameters such as uncertainty of the mechanical system and external disturbance, which are time-varying and nonlinear. Then, we propose a deterministic form of the model-based robust control algorithm to deal with the uncertainties. The proposed control algorithm is composed of two parts according to the assumed upper limit of the system uncertainties: one is the traditional proportional-derivative control, and the other is the robust control based on the Lyapunov method, which has the characteristics of model-based and error-based. The stability of the proposed control algorithm is proved by the Lyapunov method theoretically, which shows the system can maintain uniformly bounded and uniformly ultimately bounded. The experimental platform includes the rapid controller prototyping cSPACE, which is designed to reduce programming time and to improve the efficiency of the practical operation. Moreover, we adopt different friction models to investigate the effect of friction on robot performance in robot joints. Finally, numerical simulation and experimental results indicate that the control algorithm proposed in this paper has desired control performance on the SCARA robot.
3 citations
TL;DR: In this article , an adaptive robust control scheme for satellite formation-containment flying in a way of constraint following is proposed to achieve safe flight and uncertainty suppression, both collision avoidance and uncertainty suppressing are addressed.
Abstract: This article explores an adaptive robust control scheme for satellite formation-containment flying in a way of constraint following. For safe flight and uncertainty suppression, both collision avoidance and uncertainty suppression are addressed. First, for uncertainty suppression, (possibly fast) time-varying but bounded uncertainty is considered, and then an adaptive law is proposed to estimate the comprehensive uncertainty bounds online. Second, the problem of formation-containment control with collision avoidance is converted into another problem of constraint-following control by taking the objectives of collision avoidance, formation, and containment, respectively, as the collision-avoidance constraint, formation constraint, and containment constraint. Third, an $\eta $ -measure is introduced to gauge the constraint-following error, and then an adaptive robust control is proposed to render the error to be uniformly bounded and uniformly ultimately bounded, regardless of the uncertainty. By this, the satellites can follow the above collision-avoidance constraint, formation constraint, and containment constraint approximately. As a result, satellite formation-containment control emphasis on collision avoidance and uncertainty suppression is achieved.
3 citations
TL;DR: In this article , a novel estimation-based and dropout-dependent control design for distributed control systems of aeroengines with packet dropout is proposed, which is described as an independent identically distributed (i.i.d.) Bernoulli process with known probability.
Abstract: A novel estimation-based and dropout-dependent control design for distributed control systems of aeroengines with packet dropout is proposed. The packet dropout is described as an independent identically distributed (i.i.d.) Bernoulli process with known probability. The objective of the control system is to effectively and stably impel aeroengines. An inverse system is proposed to reconstruct the missing measurements, based on which, a hybrid adaptive Kalman filter (HAKF) is proposed to provide the estimated states for control design. A new state-feedback control design is developed with the estimated states and the actual states. For guaranteeing the stability of aeroengines, both the stability of HAKF and the new controlled system are analyzed and proved. The new design is applied to an aeroengine, HAKF has superior estimation accuracy which ensures the effectiveness, and the desired stability performance is achieved by controlled system in the presence of packet dropout.
3 citations
TL;DR: In this article , a robust bounded control for permanent magnet linear motor (PMLM) with inequality constraints is proposed, aiming to achieve a better performance in the trajectory tracking of PMLM.
3 citations
TL;DR: In this paper , a robust control with high-order term is proposed to compensate for the time-varying uncertainty in a PMM system and the Stackelberg game is introduced into the optimization scheme design, in which the leader plays a more important role than follower.
Abstract: There exist the uncertainties and the inequality constraints in permanent magnet synchronous motor (PMSM) system. In order to meet the safety control requirements in industrial applications, the state transformation is used to meet the inequality constraints for limiting the outputs within desired bounds. Then, fuzzy set theory, which is different from fuzzy logic, is used to describe uncertainty, and the fuzzy PMSM dynamical model is established. Based on that, a robust control with high-order term is proposed to compensate for the time-varying uncertainty. Furthermore, for improving the system performance and decreasing the control cost, the Stackelberg game is introduced into the optimization scheme design, in which the leader plays a more important role than follower. These characteristic corresponds to the influence of the two tunable control parameters on the system. Thus, the optimal parameters are obtained by the rules of Stackelberg game. Finally, experimental results show the effectiveness of the above theories.
2 citations
01 Sep 2022
TL;DR: An adaptive robust control scheme for pointing tracking of marching turret-barrel system driven by a motor and an electric cylinder is proposed to render the pointing tracking system to be practically stable; thereout, the objective of pointing tracking is achieved.
Abstract: Pointing tracking control of marching turret-barrel system is one of the important topics in exploration of intelligent ground combat platform. This paper focuses on an adaptive robust control scheme for pointing tracking of marching turret-barrel system driven by a motor and an electric cylinder. Three types of possibly fast time-varying but bounded uncertainty are considered: system modeling error, external disturbance and road excitation. The uncertainty bounds are not necessary to be known. First, the pointing tracking system is constructed as a coupled, nonlinear and uncertain dynamical system with two interconnected (horizontal and vertical) subsystems. Second, a tracking error $e$ is defined as a gauge of control objective, and then the dynamical equation of the pointing tracking system is built in state-space form. Third, for uncertainty control, a comprehensive uncertainty bound $\alpha $ is derived to measure the most conservative influence of the uncertainty, and then an adaptive law is proposed to evaluate it in real time. Finally, for pointing tracking control, an adaptive robust control is proposed to render the pointing tracking system to be practically stable; thereout, the objective of pointing tracking is achieved. This work should be among the first ever endeavours to cast all the coupling , nonlinearity and bound-unknown uncertainty into the pointing tracking framework of marching turret-barrel system.
2 citations
12 Jan 2022-Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science
TL;DR: In this paper , a robust control algorithm is proposed to solve the problem of dynamic control of collaborative robot joint module trajectory tracking, where the uncertainties include nonlinear friction, parameter uncertainty, and external disturbances.
Abstract: In order to reduce the impact of load and system parameter changes on the dynamic performance of collaborative robot joint module, a novel robust control algorithm is proposed in this paper to solve the problem of dynamic control of collaborative robot joint module trajectory tracking. The controller is composed of two parts: one is a nominal control term designed based on the dynamical model, aiming to stabilize the nominal robot system; the other is a robust control term based on the Lyapunov method, aiming to eliminate the influence of uncertainty on tracking performance, where the uncertainties include nonlinear friction, parameter uncertainty, and external disturbances. The Lyapunov minimax method is adopted to prove that the system is uniformly bounded and uniformly ultimately bounded. We performed numerical simulation and experimental validation based on an actual collaborative robot joint module experimental platform and the rapid controller prototype cSPACE. The numerical simulation and experimental results show that the controller has excellent control performance for the collaborative robot joint module and provides more accurate trajectory tracking under the influence of uncertainties.
2 citations
TL;DR: In this article , the authors proposed a method based on Udwadia-Kalaba equation to calculate the normal and lateral forces on a vehicle tracking a desired trajectory on an inclined road.
2 citations
TL;DR: In this article , a novel adaptive robust control approach has been proposed for a class of uncertain mechanical systems, aiming for the unknown uncertainties which may be fast time-varying.
Abstract: In this paper, a novel adaptive robust control approach has been proposed for a class of uncertain mechanical systems. First, aiming for the unknown uncertainties which may be fast time-varying, a novel adaptive mechanism in leakage-type will be developed. Unlike the prevalent adaptive methods, this adaptive mechanism put forward mainly accounts for estimating all the lumped uncertainty terms, and does not require any information of uncertainties other than they are bounded; Second, through transforming the gait following assignment to the constraint control, an adaptive robust constraint-following controller constructed will render the constraints uniformly bounded and uniformly ultimately bounded. To testify the efficacy of proposed approach, a lower limb exoskeleton robot is considered as an illustrative example, the simulations indicate that the proposed control can indeed improve the level of passive rehabilitation training.
TL;DR: In this paper , robust constraint-following control (RCFC) with the optimal design is developed to handle the trajectory tracking control issues for permanent magnet linear motor (PMLM), which control performance is deteriorated mainly by friction, ripple force, and external disturbance.
TL;DR: Based on the traditional PID control and robust control algorithm, a novel practical robust control method is designed for the 6-DOF collaborative industrial robot with uncertainty as discussed by the authors , which consists of a robust term and a model-based PD control term, which is called MPDP controller.
Abstract: Based on the traditional PID control and robust control algorithm, a novel practical robust control method is designed for the 6‐DOF collaborative industrial robot with uncertainty. The proposed algorithm consists of a robust term and a model‐based PD control term, which we call MPDP controller. It is demonstrated by Lyapunov theoretical analysis that the algorithm is able to guarantee uniform boundedness and uniform ultimate boundedness of the system. Simulations and experiments show the good performance of MPDP control in a robot with smaller steady‐state tracking errors and better robustness compared to PID controllers.
01 Dec 2022
TL;DR: In this article , a cooperative game-oriented optimal constraint-following problem for fuzzy mechanical systems is addressed, where the state of the concerned system is affected by possibly (fast) time-varying uncertainty.
Abstract: This article addresses a cooperative game-oriented optimal constraint-following problem for fuzzy mechanical systems. The state of the concerned system is affected by possibly (fast) time-varying uncertainty. The fuzzy set theory is adopted to describe such uncertainty. The task is to drive the system to obey a set of prescribed constraints optimally. Since the control objective may be changing along with the system uncertainty, a time-varying $\beta $ -measure is defined to gauge the constraint-following error; based on which, an adaptive robust control scheme with two tunable parameters is then proposed to render it to be uniform boundedness and uniform ultimate boundedness. For the seeking of the optimal design parameters, two cost functions, each of which is dominated by one tunable parameter, are developed with the fuzzy information, and thereout a two-player cooperative game is formulated. Finally, the optimal design problem is successfully solved: with the existence, uniqueness, and analytical expression of the Pareto optimality.
09 Jul 2022
TL;DR: In this paper , a self-adjusting leakage-type adaptive robust control is adopted which is on the basis of the tracking error to ensure the stability and maneuverability of vehicles and protect the safety of drivers and passengers.
Abstract: The research of stability control of vehicles is a hot field in industrial production and research. There are many uncertainties in the driving of vehicles. We consider these uncertainties are bounded, but unknown. A self-adjusting leakage-type adaptive robust control is adopted which is on the basis of the tracking error to ensure the stability and maneuverability of vehicles and protect the safety of drivers and passengers. The control ensures the lateral speed and yaw speed of vehicles and prevents vehicles from sideslip and yaw, regardless of the magnitude of uncertainties. Simulation results indicate the control is simple and effective for the actual control of vehicles.
09 Jul 2022
TL;DR: In this paper , a leaky adaptive robust control is adopted for parking control of the autonomous vehicle with Ackerman Angle, and the validity of the control is demonstrated by simulation result of a parallel parking trajectory.
Abstract: This paper research on the parking control of the autonomous vehicle with Ackerman Angle. So as to achieve the accurate trajectory tracking control of the autonomous vehicle, on the basis of the Udwadia-Kalaba method, a leaky adaptive robust control is adopted. The dynamic model of the autonomous vehicle is first established. Then adopt the leakage type adaptive robust control to deal with the model, and the effectiveness of the method is proved by theory. Finally, the validity of the control is demonstrated by simulation result of a parallel parking trajectory.
27 Jun 2022
TL;DR: In this paper , an adaptive robust constraint-following control approach with tunable parameters was developed with a two-player cooperative game oriented optimal design problem, and the problem was completely solved with the existence and uniqueness of the optimal solution proved and the analytical expression of optimal parameters provided.
Abstract: This paper examines the adaptive robust control for uncertain underactuated mechanical systems. The uncertainty is time varying but bounded. An adaptive robust constraint-following control approach is developed with tunable parameters. For the seeking of optimal control parameters, a two-player cooperative game oriented optimal design problem is formulated. The problem is completely solved with the existence and uniqueness of the optimal solution proved and the analytical expression of the optimal parameters provided. Using the optimal parameters, the proposed adaptive robust control renders dual performance: guaranteed (uniform boundedness and uniform ultimate boundedness) and optimal.
01 Oct 2022
TL;DR: In this paper , a robust control method is proposed, which can ensure the uniformly bounded and uniformly ultimately bounded of the controlled mechanical system, where the exact value of the boundary is unknown.
Abstract: Mechanical systems with (possibly fast) time-varying but bounded uncertainty are considered. The exact value of the boundary is unknown. All the designer can get is that the boundary values are in a (known) fuzzy set. On the basis, a robust control method is proposed, which can ensure the uniformly bounded and uniformly ultimately bounded of the controlled mechanical system. The control contains two flexibly selectable design parameters. We seek to choose the optimal parameters. For a superior performance, two fuzzy-set-based performance indices are proposed to reflect the transient performance as well as the steady-state performance. Each performance index can be influenced by two design parameters. However, influences are nonconciliatory. This poses a design dilemma: the increase of a parameter may harness one performance while inflict the other. Therefore, the “optimal” choice of the design parameters is not intuitively clear. To resolve this dilemma, the two-player Nash-based noncooperative game theory is adopted, which is a notable feature of this article. Once the problem is formulated, we show that there is always a Nash-equilibrium solution to the two-player problem. We also show how to find it. The approach is very general, which also can be extended to $n$ -player Nash game for future research. The control is applied to a compressor powered by permanent magnet synchronous motor (PMSM) as a demonstration. The resulting performance shows that this Nash-based robust control design is both practical and effective.
30 Dec 2022-Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science
TL;DR: In this paper , a dynamic robust control approach for cooperative robots with inequality constraints is proposed, where the inequality constraint is eliminated by choosing proper boundary function and using state transformation, which can compensate errors caused by uncertainties and external disturbances.
Abstract: In this paper, a new practical dynamic robust control approach for cooperative robots with inequality constraints is proposed. The controller can compensate errors caused by uncertainties and external disturbances. The inequality constraint is eliminated by choosing proper boundary function and using state transformation. In this way, the controlled output is guaranteed within the desired range. The Lyapunov minimax method is used to prove that the controller can guarantee the uniform boundedness and uniform ultimate boundedness and stability of the robot system. Experimental verifications are carried out on a 2-DOF cooperative robot experimental platform with joint modules. The experimental platform is equipped with a rapid prototyping controller system (CSPACE). Numerical simulation and experimental verification results show that the proposed practical robust controller has significant advantages of trajectory tracking performance and security for cooperative robots with inequality constraints.
09 Jul 2022
TL;DR: In this paper , a fuzzy approach is applied to describe uncertainties of a collaborative robot based on the membership function, and a high-order robust control is designed to compensate for uncertainties.
Abstract: Uncertainties exist in control fields which have a significant impact both on system performance and control cost. A fuzzy approach is applied to describe uncertainties of a collaborative robot based on the membership function. Then a high-order robust control is designed to compensate for uncertainties. The performances of uniform boundedness and uniform ultimate boundedness are obtained. To increase system performance and decrease control cost, the optimal control parameters are solved based on game theory to balance performance and cost. In the end, the control effects are verified based on simulation results by comparing with other classical control methods.
TL;DR: In this article , the robust bounded control problem for the permanent magnet linear motors with inequality constraints is studied, where the dynamical model of the system is built, through the state transformation, to satisfy the inequality constraint of the position output.
Abstract: The robust bounded control problem for the permanent magnet linear motors with inequality constraints is studied. Firstly, the dynamical model of the system is built, through the state transformation is used to satisfy the inequality constraint of the position output. Thus, the controller after the state transformation can ensure that the control output of the linear motor stays the desired range. Selecting the appropriate boundary function, and then the upper and lower bounds of the control output can be set according to our control requirements. The control scheme can guarantee uniform boundedness and uniform ultimate boundedness. The results of experiments and simulation show that the proposed algorithm can assure the control output within the desired range regardless of the uncertainty.
09 Jul 2022
TL;DR: In this paper , a robust deterministic control based on transformation function is creatively proposed to achieve global practical stability and suppress the nonlinearity caused by approximation error, external disturbances, and saturation.
Abstract: This paper investigates the problem of nonlinear systems with input saturation and unknown bounded time-varying external uncertainties. We introduce an appropriate clipping function to represent input saturation and make the saturation model continuously differentiable. Robust deterministic control based on transformation function is creatively proposed to achieve global practical stability and suppress the nonlinearity caused by approximation error, external disturbances, and saturation. The control is applied to the turbofan engine model, and its effectiveness is illustrated by the numerical simulation.