scholarly journals Design, Modeling and Control of Bionic Knee in Artificial Leg

Author(s):  
Hualong Xie ◽  
Yao Xie ◽  
Fei Li

The biped robot with heterogeneous legs (BRHL) greatly facilitates the development of intelligent lower-limb prosthesis (ILLP). In the BRHL, the remaining leg of the amputee is simulated by an artificial leg, which provides the bionic leg with the precise gait following trajectory. Therefore, the artificial leg must closely mimic the features of the human leg. After analyzing the motion mechanism of the human knee, this paper designs a four-link bionic knee in light of the coexistence of rolling and sliding between the femur, the meniscus and the tibia. Drawing on the driving mechanism of leg muscles, two pneumatic artificial muscles (PAMs) were adopted to serve as the extensor and flexor muscles on the thigh. The two PAMs move in opposite direction, driving the knee motions in the artificial leg. To overcome the complexity of traditional PAM modelling methods, the author set up a PAM feature test platform to disclose the features of the PAMs, and built static and dynamic nonlinear mathematical models of the PAMs based on the test data. Next, a proportional-integral-derivative (PID) closed loop controller and sliding mode controller was designed for the bionic knee, referring to the kinetics equation of the knee. Through experimental simulation, it is confirmed that the proposed controller can accurately control the position of the four-link bionic knee, and that the designed bionic knee and PAM driving mode are both correct.

2007 ◽  
Vol 31 (1) ◽  
pp. 127-141
Author(s):  
Yonghong Tan ◽  
Xinlong Zhao

A hysteretic operator is proposed to set up an expanded input space so as to transform the multi-valued mapping of hysteresis to a one-to-one mapping so that the neural networks can be applied to model of the behavior of hysteresis. Based on the proposed neural modeling strategy for hysteresis, a pseudo control scheme is developed to handle the control of nonlinear dynamic systems with hysteresis. A neural estimator is constructed to predict the system residual so that it avoids constructing the inverse model of hysteresis. Thus, the control strategy can be used for the case where the output of hysteresis is unmeasurable directly. Then, the corresponding adaptive control strategy is presented. The application of the novel modeling approach to hysteresis in a piezoelectric actuator is illustrated. Then a numerical example of using the proposed control strategy for a nonlinear system with hysteresis is presented.


2019 ◽  
pp. 20-66
Author(s):  
Heba Elkholy ◽  
Maki K. Habib

This chapter presents the detailed dynamic model of a Vertical Take-Off and Landing (VTOL) type Unmanned Aerial Vehicle (UAV) known as the quadrotor. The mathematical model is derived based on Newton Euler formalism. This is followed by the development of a simulation environment on which the developed model is verified. Four control algorithms are developed to control the quadrotor's degrees of freedom: a linear PID controller, Gain Scheduling-based PID controller, nonlinear Sliding Mode, and Backstepping controllers. The performances of these controllers are compared through the developed simulation environment in terms of their dynamic performance, stability, and the effect of possible disturbances.


Author(s):  
A. Narimani ◽  
M. F. Golnaraghi

Semi-active isolators offer significant improvement in performance over passive isolators. These systems benefit from the advantages of active systems with the reliability of the passive systems. In this work we study a vibration isolation system with a magnetorheological (MR) damper. The experimental investigation of the mechanical properties of a commercially available linear MR damper (RD-1005-3) was conducted next. The mathematical Bouc-Wen model was adopted to predict the performance of MR damper. In addition, a modified Bingham model has been developed to characterize the damper behavior more accurately and efficiently. The measured hysteresis characteristics of field-dependent damping forces are compared with the simulation results from the described mathematical models. The accuracy of a damping-force controller using the proposed method is also demonstrated experimentally. Finally, a scaled quarter car model is set up to study the performance of the control strategy. The experimental results show that with the semi-active control the vibration of the quarter car model is well controlled.


2020 ◽  
Author(s):  
Zewen LIN ◽  
Zhenzhong Wang ◽  
Xuepeng HUANG

Abstract The spin axis of bonnet tool maintains a constant angle (precession angle) with the normal of polishing point in polishing. In this paper, a controlled model was established on robotic machining platform to polish large diameter axisymmetric aspheric optics. Based on the transformation relationship in spatial coordinate system, the relationships between workpiece coordinate system, polishing point local coordinate system and the bonnet tool coordinate system were set up respectively. So that the movement model of bonnet precession polishing was obtained. What’s more, the efficiency optimal control was added to the movement model. the trajectories and poses of the polishing were determined, and the change of robot linkage angle difference was obtained. Finally, the precession movement model and the control algorithm were verified by the simulation in the Robotstudio, an offline simulation software and experiment for plane component.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hind Elaimani ◽  
Ahmed Essadki ◽  
Noureddine Elmouhi ◽  
Rachid Chakib

The modeling and control of a wind energy conversion system based on the Doubly Fed Induction Generator DFIG is the discussed theme in this paper. The purpose of this system was to control active and reactive power converted; this control is ensured thanks to the control of the two converters. The proposed control strategies are controlled by PI regulators and the sliding mode technique. In the present work a comparison of the robustness of the 2 controls of the grid side converter (GSC) during a voltage dip is shown. The simulation is carried out using the Matlab/Simulink software with a 300 kW generator.


Sign in / Sign up

Export Citation Format

Share Document