Vertical Planar Underactuated Manipulation Using a Gravity Compensation Mechanism

2005 ◽  
Vol 17 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Yoshiki Ono ◽  
◽  
Toshio Morita ◽  
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Equilibrium Points ◽  
Gravity Compensation ◽  
Compensation Mechanism ◽  
Angular Variation ◽  
Underactuated Manipulator ◽  
Zero Equilibrium ◽  
Three Degrees Of Freedom ◽  
Active Base

We propose generating and erasing equilibrium points for passive joints, together with an underactuated manipulator having both vertical and horizontal planar type. This manipulator implements three degrees of freedom (DOF) by combining a passive two-DOF mechanical gravity canceller and an active base joint. Equilibrium points are erased and adjusted by angular variation of the base joint so equilibrium points are erased when gravity torque is zero. If gravity torque is not zero, equilibrium points depend on angular variation of the base joint. Experimental results show position control of the distal link through the mechanical gravity canceller is effective for underactuated manipulation.

Analysis of Vehicle Dynamic Equilibrium Points with 3-DOF Based on Genetic Algorithm

2014 ◽  
Vol 608-609 ◽  
pp. 721-725
Author(s):  
Rong Li ◽  
Wei Min Li
Keyword(s):  
Genetic Algorithm ◽  
Vehicle Dynamics ◽  
Optimization Design ◽  
Degrees Of Freedom ◽  
Dynamic Equilibrium ◽  
Equilibrium Points ◽  
Vehicle Handling ◽  
Dynamic Modification ◽  
The Stability ◽  
Three Degrees Of Freedom

To further study the stability of vehicle dynamics, a vehicle handling stability’s nonlinear model (including longitudinal, lateral and yaw movement three degrees of freedom) was established. Genetic algorithm was proposed for the vehicle dynamics system’s equilibrium points with 3-DOF. This algorithm solves the problem that cannot be solved through the traditional analytic algorithms and numerical methods. Comparing with the existing research results, the feasibility of solving the equilibrium point by the genetic algorithm is verified. It provides the theoretical foundation for dynamic modification and optimization design of powertrain.

Model-Based Control of Three Degrees of Freedom Robotic Bulldozing

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Scott G. Olsen ◽  
Gary M. Bone
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Removal Rate ◽  
Optimal Controller ◽  
Control Laws ◽  
Rule Based ◽  
Three Degrees Of Freedom

This brief paper investigates the control of a robotic bulldozing operation. Optimal blade position control laws were designed based on a hybrid dynamic model to maximize the predicted material removal rate of the bulldozing process. Experiments were conducted with a scaled-down robotic bulldozing system. The control laws were implemented with various tuning values. As a comparison, a rule-based blade control algorithm was also designed and implemented. The experimental results with the best optimal controller demonstrated a 33% increase in the average material removal rate compared to the rule-based controller.

scholarly journals Nonlinear pd controllers with gravity compensation for robot manipulators

2014 ◽  
Vol 14 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Jianfeng Huang ◽  
Chengying Yang ◽  
Jun Ye
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Nonlinear Function ◽  
Step Response ◽  
Robot Dynamics ◽  
Gravity Compensation ◽  
Pd Controller ◽  
Globally Asymptotically Stable

Abstract A Nonlinear Proportional-Derivative (NPD) controller with gravity compensation is proposed and applied to robot manipulators in this paper. The proportional and derivative gains are changed by the nonlinear function of errors in the NPD controller. The closed-loop system, composed of nonlinear robot dynamics and NPD controllers, is globally asymptotically stable in position control of robot manipulators. The comparison of the simulation experiments in the position control (the step response) of a robot manipulator with two degrees of freedom is also presented to illustrate that the NPD controller is superior to the conventional PD controller in a position control system. The experimental results show that the NPD controller can obtain a faster response velocity and higher position accuracy than the conventional PD controller in the position control of robot manipulators because the proportional and derivative gains of the NPD controller can be changed by the nonlinear function of errors. The NPD controller provides a novel approach for robot control systems.

Control of three degrees-of-freedom underactuated manipulator using fuzzy based switching

2004 ◽  
Vol 8 (2) ◽  
pp. 153-158
Author(s):  
Lanka Udawatta ◽  
Keigo Watanabe ◽  
Kiyotaka Izumi ◽  
Kazuo Kiguchi
Keyword(s):  
Degrees Of Freedom ◽  
Underactuated Manipulator ◽  
Three Degrees Of Freedom

Improved performance for robot manipulators via transmission re-design: the SPRINTA

Robotica ◽  
2000 ◽  
Vol 18 (2) ◽  
pp. 195-200
Author(s):  
P.J. Turner ◽  
P. Nigrowsky ◽  
G. Vines
Keyword(s):  
Degrees Of Freedom ◽  
Robot Manipulators ◽  
Tracking Error ◽  
Reduction Ratio ◽  
Practical Implementation ◽  
Gravity Compensation ◽  
Direct Drive ◽  
Dynamic Decoupling ◽  
Improved Performance ◽  
Three Degrees Of Freedom

A new design philosophy for the transmission of robot manipulators is proposed and an example of a practical implementation is presented. The philosophy combines the advantages of conventional geared robots in terms of relocating the actuators away from the joints and the alternative direct-drive approach. The gimbal drive is an example of a non-linear transmission where there is negligible friction, no backlash or compliance and which provides a varying reduction ratio for gravity compensation and for some dynamic decoupling. The gimbal drive is implemented on the three degrees of freedom SPRINTA prototype. Static repeatability, as well as tracking error and dynamic repeatability for the industrial goalpost test are measured. The performance demonstrates the potential of such a type of robot.

An Underactuated Manipulation Method Using a Mechanical Gravity Canceller

2004 ◽  
Vol 16 (6) ◽  
pp. 563-569 ◽  
Author(s):  
Yoshiki Ono ◽  
◽  
Toshio Morita
Keyword(s):  
Equilibrium Points ◽  
Experimental Results ◽  
Active Joint ◽  
Underactuated Manipulator ◽  
Active Base

This paper propose a method, to stabilize the arbitrary posture of a distal link by generating and erasing equilibrium points in passive joints of a vertical planar underactuated manipulator with an active joint in the base. A vertical planar three-DOF manipulator combining a passive two-DOF mechanical gravity canceller and an active base joint was developed. Experimental results demonstrate the effectiveness of this method.

scholarly journals Kinematic-Model-Free Orientation Control for Robot Manipulation Using Locally Weighted Dual Quaternions

Robotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Ahmad AlAttar ◽  
Petar Kormushev
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Kinematic Model ◽  
Model Learning ◽  
Orientation Control ◽  
Dual Quaternions ◽  
Model Free ◽  
Novel Method ◽  
Model Free Controller ◽  
Three Degrees Of Freedom

Conventional control of robotic manipulators requires prior knowledge of their kinematic structure. Model-learning controllers have the advantage of being able to control robots without requiring a complete kinematic model and work well in less structured environments. Our recently proposed Encoderless controller has shown promising ability to control a manipulator without requiring any prior kinematic model whatsoever. However, this controller is only limited to position control, leaving orientation control unsolved. The research presented in this paper extends the state-of-the-art kinematic-model-free controller to handle orientation control to manipulate a robotic arm without requiring any prior model of the robot or any joint angle information during control. This paper presents a novel method to simultaneously control the position and orientation of a robot’s end effector using locally weighted dual quaternions. The proposed novel controller is also scaled up to control three-degrees-of-freedom robots.

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