Sliding Mode Control for Heart Rate Regulation of Electric Bicycle Riders

Author(s):  
Daniel Meyer ◽  
Wenlong Zhang ◽  
Masayoshi Tomizuka

In this paper a new controller for electric bicycles is proposed to maintain a desired heart rate level and improve the riding experience of cyclists. The controller achieves this by adequately adjusting the motor assistance without affecting the cycling velocity. First, a human heart rate model is fitted to experimental data to model the heart rate response of cyclists during different exercises. Then, a sliding mode controller is designed to keep the human heart rate at a predefined level. Furthermore, a feedforward controller is introduced into the system to improve both the tracking performance and riding experience. The feedforward controller consists of an inverse human heart rate response model, which estimates the necessary rider torque for a desired heart rate level. The controller is implemented with a commercial electric bicycle. Simulation and experimental results are presented to assess the validity of the controller. Whereas the sliding mode controller itself achieves good tracking performance, the sliding mode control combined with the feedforward control additionally reduces the maximal exerted rider torque and improves the riding experience.

2021 ◽  
Vol 9 (9) ◽  
pp. 1000
Author(s):  
Weilei Mu ◽  
Yuxue Wang ◽  
Hailiang Sun ◽  
Guijie Liu

To solve the trajectory tracking problem of insufficient response and the large tracking error of remotely operated vehicles (ROVs) under the interference of large ocean currents, this paper proposes a double-loop sliding mode controller with an ocean current observer. The designed controller consisted of an outer-loop controller (the position controller) and an inner-loop controller (the velocity controller): the outer controller was designed by the position error, and a reference velocity was created for the inner loop to achieve accurate positioning and attitude tracking. The reference control input was treated as a new target to design the inner-loop controller, enabling the ROV to achieve accurate reference velocity tracking. Based on the theoretical idea of active disturbance rejection control, a kinematic equation-based ocean current observer was designed to estimate and compensate for large unknown currents to ensure accurate trajectory tracking performance under large currents. The simulation results proved that the double-loop sliding-mode control scheme with an ocean current observer always showed good tracking performance, demonstrating the excellent control performance and high robustness of the scheme. Compared with the high-complexity control schemes such as neural network-based PID control or fuzzy sliding mode control, it effectively improves the robustness to ocean current disturbances without increasing the computational effort excessively, and is more practical in ROV systems with limited computational power.


Author(s):  
J. Fei

This paper presents an adaptive feedforward control scheme using the least mean square (LMS) algorithm combined with sliding mode control for a flexible beam using piezoceramic actuator. A finite element model of the dynamic response of flexible beam system with PZT patches is derived and analyzed. Implementation of an adaptive LMS feedforward controller has the advantages of inherent stability and simplicity in design. The proposed adaptive LMS feedforward control system maintains the basic structure of the adaptive feedforward controller, but incorporates reference model in the system. Discrete sliding mode controller is added in the feedback loop to enhance the robustness of control system subjected to the variation of system parameters and external disturbances. Simulation results from flexible beam model verify the effectiveness of the proposed adaptive LMS feedforward with sliding mode control scheme and good disturbance rejection properties.


Author(s):  
Imen Saidi ◽  
Asma Hammami

Introduction: In this paper, a robust sliding mode controller is developed to control an orthosis used for rehabilitation of lower limb. Materials and Methods: The orthosis is defined as a mechanical device intended to physically assist a human subject for the realization of his movements. It should be adapted to the human morphology, interacting in harmony with its movements, and providing the necessary efforts along the limbs to which it is attached. Results: The application of the sliding mode control to the Shank-orthosis system shows satisfactory dynamic response and tracking performances. Conclusion: In fact, position tracking and speed tracking errors are very small. The sliding mode controller effectively absorbs disturbance and parametric variations, hence the efficiency and robustness of our applied control.


2014 ◽  
Vol 678 ◽  
pp. 399-405
Author(s):  
Yan Mei

Bidirectional DC/DC converter is used for the battery charging and discharging. The sliding mode controller based on state space averaging algorithm is used for controlling bidirectional DC/DC converter. Two kinds of working modes, buck mode and boost mode, have been analyzed and three kinds of working states which are consisted by two working modes have been deeply discussed, and the automatic switch logic diagram when battery charging and discharging through the bidirectional DC/DC converter has been presented. Situation of system based on S1, S2 conducting alternately has been studied, and the simulations were also presented. According to the results, the characteristics of good stability and transient can be confirmed.


2021 ◽  
Author(s):  
Manjeet Tummalapalli

This project proposes a new SCARA variant with 4 degree of freedom. The proposed variant is achieved by swapping joint 2 and joint 3 of the standard SCARA robots. An adaptive controller is defined based on the advantages and disadvantages of PD, and SMC controllers.The purpose of the project is to understand the dynamics of the variant and to track the performance for trajectories. Simulations for tracking performance are carried under linear and circular trajectories. The variant is studied over the three controllers; PD, PD-SMC and A-PD-SMC. The variant under the adaptive controller is most efficient in terms of tracking performance and the control inputs to the system. The system is simulated under high speed and with the influence of friction at the joints. The control gains are held constant for both the trajectories and hence the controller is able to perform good under changing trajectories. Due to the use of the adaptive law, the system is at the ease of implementation and since no priori knowledge if the system is needed, it is model free. Therefore, the proposed adaptive PD-SMC has proven to provide good, robust trajectory tracking.


Author(s):  
Trong-Thang Nguyen

In this research, the author presents the model of the two-link robot arm and its dynamic equations. Based on these dynamic equations, the author builds the sliding mode controller for each joint of the robot. The tasks of the controllers are controlling the Torque in each Joint of the robot in order that the angle coordinates of each link coincide with the desired values. The proposed algorithm and robot model are built on Matlab-Simulink to investigate the system quality. The results show that the quality of the control system is very high: the response angles of each link quickly reach the desired values, and the static error equal to zero.


2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Dilan Chen ◽  
Weidong Zhang

This paper is concerned with the sliding mode control for uncertain stochastic neutral systems with multiple delays. A switching surface is adopted first. Then, by means of linear matrix inequalities (LMIs), a sufficient condition is derived to ensure the global stochastic stability of the stochastic system in the sliding mode for all admissible uncertainties. The synthesized sliding mode controller guarantees the existence of the sliding mode.


Author(s):  
Ehsan Sarshari ◽  
Nastaran Vasegh ◽  
Mehran Khaghani ◽  
Saeid Dousti

Ziegler’s pendulum is an appropriate model of a non-conservative dynamic system. By considering gravity effect, new equations of motion are extracted from Newton’s motion laws. The instability of equilibriums is determined by linear stability analysis. Chaotic behavior of the model is shown by numerical simulations. Sliding mode controller is used for eliminating chaos and for stabilizing the equilibriums.


Author(s):  
Jinwei Sun ◽  
JingYu Cong ◽  
Liang Gu ◽  
Mingming Dong

As the possibility of faults in active suspension actuators are higher and more severe compared to other components, this study presents a fault-tolerant control approach based on the second-order sliding mode control method. The aim of the controller is to improve riding comfort, guarantee handling stability, and provide adequate suspension stroke in the presence of disturbances and actuator faults. A nonlinear full-vehicle suspension system and hydraulic actuator with nonlinear characteristics are adopted for accurate control. Firstly, a nonlinear sliding manifold based on a nonsingular fast terminal sliding mode controller is introduced to suppress the sprung mass heave, pitch, and roll motions arising from road disturbances. Secondly, a second-order sliding mode-based super twisting controller is utilized to track the desired forces generated by the nonsingular fast terminal sliding mode controller with actuator faults and uncertainties. The controllers are robust against disturbances, uncertainties, and faults. Moreover, the stability of the super twisting controller is proved by the strong Lyapunov functions. Finally, numerical simulations are performed to demonstrate the effectiveness of the controller. Four different conditions, random road profile, bump road excitation, single-wheel bump excitation, and partial faults are considered. The main contributions of this study are: (1) combination of the above algorithms to deal with actuator faults and improve active suspension performance; (2) the controller proposed in this study has a simple structure. Simulation results indicate that the nonsingular fast terminal sliding mode super twisting controller can guarantee the performance of the closed-loop system under both faulty and healthy conditions.


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