On trajectory tracking control of fluid-driven actuators

2021 ◽  
Vol 69 (11) ◽  
pp. 970-980
Author(s):  
Kathrin Hoffmann ◽  
Daniel Müller ◽  
René Simon ◽  
Oliver Sawodny
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Direct Drive ◽  
Trajectory Tracking Control ◽  
Pressure Dynamics ◽  
Safety Features ◽  
Fluidic Muscle ◽  
6 Degrees Of Freedom ◽  
The Mathematical Model

Abstract Fluid-driven actuators are not only well-established in automation, but also a promising drive technology for collaborative robots. Their inherent compliance due to the compressibility of suitable fluids such as air, as well as their direct drive properties are advantageous safety features for human-machine collaboration. In this work, we provide an overview of different fluid-driven manipulators, namely fluidic muscle actuated ones, continuum manipulators, and those with rotary joints. For the latter, we introduce the mathematical model including mechanics and pressure dynamics and describe its properties such as strong nonlinearities, which make trajectory tracking control challenging. A model-based nonlinear cascaded controller is presented. Experimental results on a 6 degrees of freedom (DOF) prototype demonstrate the resulting trajectory tracking performance.

Prescribed performance trajectory tracking control of dynamic positioning ship under input saturation

2020 ◽  
pp. 014233122092888
Author(s):  
Yuanhui Wang ◽  
Haibin Wang ◽  
Mingyu Fu
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Input Saturation ◽  
Small Neighborhood ◽  
Performance Criteria ◽  
Dynamic Positioning ◽  
Trajectory Tracking Control ◽  
Prescribed Performance ◽  
Control Scheme

This paper investigates concentrates on the trajectory tracking control problem of dynamic positioning (DP) ship, in the presence of the time-varying disturbance and input saturation. Firstly, a simplified mathematical model of three degrees of freedom is established. According to the characteristics of the DP ship, an adaptive backstepping controller which combine the prescribed performance function with disturbance observer is proposed. The control scheme can guarantee the transient and steady state performance of the trajectory tracking and meet the prescribed performance criteria. In addition, an auxiliary dynamic system is introduced into the controller to deal with the input saturation problem of the actuator, so that the DP ship can accomplish the task of trajectory tracking under the condition of actuator constraint. Subsequently, in combination of barrier Lyapunov function (BLF), it is proved that the DP system can stabilize and converge rapidly to the small neighborhood of the equilibrium point, which can achieve the prescribed performance. Finally, the effectiveness of the DP control law is demonstrated by a series of simulation experiments.

scholarly journals Trajectory tracking control of two degrees-of-freedom helicopter based on Udwadia–Kalaba theory

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880893
Author(s):  
Yinfei Zhu ◽  
Han Zhao ◽  
Hao Sun ◽  
Kang Huang ◽  
Yinghui Dong
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Initial Conditions ◽  
Control Cost ◽  
Trajectory Tracking Control ◽  
Constraint Force ◽  
Two Degrees Of Freedom ◽  
High Control

In this article, by using Lagrange energy method, we establish the dynamical model of a two degrees-of-freedom helicopter, which is subject to holonomic constraints. A control method based on Udwadia–Kalaba theory is proposed to achieve the trajectory tracking control of the 2-degrees-of-freedom helicopter. Different from traditional methods, this method could solve the constraint force of the mechanical system without adding additional parameters such as Lagrange multipliers. When initial conditions are compatible, we can use the nominal control which is based on Udwadia–Kalaba equation to control 2-degrees-of-freedom helicopter in real time. But when initial conditions have incompatibility, the simulation result could produce divergence phenomenon. To solve the trajectory tracking control problem of 2-degrees-of-freedom helicopter under incompatible initial conditions, a modified controller is proposed. We also make simulation contrast by different control methods to validate the effectiveness and superiority of the modified controller. Simulation results show that the modified controller can drive the 2-degrees-of-freedom helicopter to perfectly track the desired trajectory with less control cost and high control accuracy.

Curve-constrained collision-free trajectory control of hyper-redundant planar space robot

2017 ◽  
Vol 231 (4) ◽  
pp. 282-298 ◽  
Author(s):  
Vijay Kumar Dalla ◽  
Pushparaj Mani Pathak
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Space Robot ◽  
Redundancy Resolution ◽  
Trajectory Tracking Control ◽  
Planar Space ◽  
Control Approach ◽  
Control Purpose

Redundancy resolution in a hyper-redundant space robots is a big challenge due to its extra degrees of freedom. This article presents a methodology to control motion planning of a planar space robot with multiple links, that is, hyper-redundant space robot. For control purpose, first a curve-constrained link trajectory tracking control has been developed. Then, the developed control approach has been extended for a collision-free trajectory tracking. For curve-constrained link trajectory tracking control, the backbone reference set (curve fitting) has been applied to exploit the redundancy of two-dimensional space robot of multiple links. For kinematic control purpose, a limited number of joints are actuated. The hyper-redundant space robot has the advantage that manipulator can be configured differently through actuation of different joints. The concept of a limited number of joint actuation has further been extended for collision-free trajectory tracking in the workspace in the presence of obstacles. Collision avoidance is based on the configuration transformation approach where the joints are made active or fixed joint position to facilitate collision-free tip trajectory. Before configuration transformation, collision detection has been performed based on the pseudo-distance criterion. The bond graph technique has been used for the dynamic model of the system and to formulate system equations. The simulation and the animation results validated the successful execution of the proposed approaches for the curve-constrained collision-free trajectory planning.

scholarly journals Intelligent Controller Design for Quad-Rotor Stabilization in Presence of Parameter Variations

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Oualid Doukhi ◽  
Abdur Razzaq Fayjie ◽  
Deok Jin Lee
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Controller Design ◽  
Flight Period ◽  
Test Bed ◽  
Trajectory Tracking Control ◽  
Highly Nonlinear ◽  
Self Tuning ◽  
Aerial Vehicle ◽  
The Mathematical Model

The paper presents the mathematical model of a quadrotor unmanned aerial vehicle (UAV) and the design of robust Self-Tuning PID controller based on fuzzy logic, which offers several advantages over certain types of conventional control methods, specifically in dealing with highly nonlinear systems and parameter uncertainty. The proposed controller is applied to the inner and outer loop for heading and position trajectory tracking control to handle the external disturbances caused by the variation in the payload weight during the flight period. The results of the numerical simulation using gazebo physics engine simulator and real-time experiment using AR drone 2.0 test bed demonstrate the effectiveness of this intelligent control strategy which can improve the robustness of the whole system and achieve accurate trajectory tracking control, comparing it with the conventional proportional integral derivative (PID).

Control of Flexible-Link Multiple Manipulators

2001 ◽  
Vol 124 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Qiao Sun
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Internal Force ◽  
Zero Dynamics ◽  
Nonlinear Inversion ◽  
Flexible Link ◽  
Trajectory Tracking Control ◽  
Multiple Manipulators

In this paper, we consider the object trajectory tracking control for flexible-link cooperating manipulators. In particular, we develop a stable inversion control law which is commonly known as the inverse dynamics control or the computed torque method for rigid manipulators. Difficulties in applying this method to the control of flexible link manipulators are due to the fact that the inverse dynamics system is generally unstable because of the inherently unstable zero dynamics. As such, bounded actuator torques cannot be guaranteed. For multiple manipulators handling a common object, there are more actuators than the degrees of freedom of the system. Through decomposing the manipulator end-effector wrenches into resultant and internal force components, control laws are derived such that the internal forces are used to stabilize the system zero dynamics. Consequently, nonlinear inversion control can be applied for the object trajectory tracking control. Numerical simulations are performed to illustrate the performance of the control strategy developed in the paper.

Object Trajectory Tracking Control for Flexible-Link Multiple Manipulators

1999 ◽  
Author(s):  
Qiao Sun
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Internal Force ◽  
Nonlinear Inversion ◽  
Flexible Link ◽  
Trajectory Tracking Control ◽  
Force Components ◽  
Multiple Manipulators

Abstract In this paper, we consider the object trajectory tracking control for flexible-link cooperating manipulators. In particular, we develop a stable inversion control law which is commonly known as the inverse dynamics control or the computed torque method for rigid manipulators. Difficulties in applying this method to the control of flexible link manipulators are due to the fact that the inverse dynamics system is generally unstable. As such, bounded actuator torques cannot be guaranteed. For multiple manipulators handling a common object, there are more actuators than the degrees of freedom of the system. Through decomposing the manipulator end-effector wrenches into resultant and internal force components, control laws are designed such that the internal forces are used to stabilize the system zero dynamics. Consequently, nonlinear inversion control can be applied for the object trajectory tracking control.

scholarly journals Inverse dynamics and trajectory tracking control of a new six degrees of freedom spatial 3-RPRS parallel manipulator

2017 ◽  
Vol 8 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Santhakumar Mohan ◽  
Burkhard Corves
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Virtual Prototype ◽  
Trajectory Tracking Control ◽  
Six Degrees Of Freedom ◽  
Control Scheme ◽  
Computer Based

Abstract. This paper presents the complete dynamic model of a new six degrees of freedom (DOF) spatial 3-RPRS parallel manipulator. The geometry parameters of the manipulator are optimized for a given constant orientation workspace. Further, a robust task-space trajectory tracking control is also designed for the manipulator along with a nonlinear disturbance observer. To demonstrate the efficacy and show the complete performance of the proposed controller, virtual prototype experiments are executed using one of the multibody dynamics software namely MSC Adams. The computer-based virtual prototype experiment results show that the manipulator tracking performance is satisfactory with the proposed control scheme. In addition, the controller parameter sensitivity and robustness analyses are also accomplished.

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