Point-to-Point Motion Planning for Servosystems With Elastic Transmission Via Optimal Dynamic Inversion1

2001 ◽  
Vol 123 (4) ◽  
pp. 733-736 ◽  
Author(s):  
Aurelio Piazzi ◽  
Antonio Visioli
Keyword(s):  
Optimization Procedure ◽  
Dynamic Inversion ◽  
Residual Vibration ◽  
Inversion Point ◽  
Stiffness Constant ◽  
Point Motion ◽  
Optimal Dynamic ◽  
A New Technique ◽  
Point To Point ◽  
Definition Of

A new technique, based on dynamic inversion, for the residual vibration reduction in the point-to-point motion of servosystems with elastic transmission is presented. The methodology consists of defining a suitable motion law for the load, and subsequently determining, via dynamic inversion, the corresponding command function for the system. The method inherently assures the robustness of the control scheme despite inaccuracies in the estimation of the stiffness constant and of the damping of the transmission. The main contribution of the paper lies in the definition of a simple optimization procedure which allows the system inversion point that minimizes the residual vibration to be found. Experimental results show that in this way the identification phase is less critical and performances can be significantly improved.

Friction-Compensating Command Shaping for Vibration Reduction

2004 ◽  
Vol 127 (4) ◽  
pp. 307-314 ◽  
Author(s):  
Jason Lawrence ◽  
William Singhose ◽  
Keith Hekman
Keyword(s):  
Steady State ◽  
Coulomb Friction ◽  
Vibration Reduction ◽  
Input Shaping ◽  
Residual Vibration ◽  
Command Shaping ◽  
Point Motion ◽  
Common Operation ◽  
Point To Point ◽  
Theoretical Developments

Fast and accurate point-to-point motion is a common operation for industrial machines, but vibration will frequently corrupt such motion. This paper develops commands that can move machines without vibration, even in the presence of Coulomb friction. Previous studies have shown that input shaping can be used on linear systems to produce point-to-point motion with no residual vibration. This paper extends command-shaping theory to nonlinear systems, specifically systems with Coulomb friction. This idea is applied to a PD-controlled mass with Coulomb friction to ground. The theoretical developments are experimentally verified on a solder cell machine. The results show that the new commands allow the proportional gain to be increased, resulting in reduced rise time, settling time, and steady-state error.

Analytical Trajectory Optimization of Seven Degrees of Freedom Redundant Robots

1987 ◽  
Vol 11 (4) ◽  
pp. 197-200 ◽  
Author(s):  
B. Benhabib ◽  
R.G. Fenton ◽  
A.A. Goldenberg
Keyword(s):  
Trajectory Planning ◽  
Trajectory Optimization ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Optimization Procedure ◽  
Redundant Robots ◽  
Point Motion ◽  
Point To Point ◽  
Lagrange’S Method

The basic characteristic of kinematically redundant robots is that non-unique joint solutions may exist for a specified end effector location. Thus, trajectory planning for a kinematically redundant robot requires an optimization procedure to determine the joint displacements when solving the inverse kinematics relations. In this paper an analytical solution is developed for the trajectory optimization problem of redundant robots based on the classical Lagrange’s method. A detailed formulation is provided for seven degrees of freedom robots, which minimizes the Euclidean norm of joint dislacements for point-to-point motion trajectory planning.

Minimizing Residual Vibration for Point-to-Point Motion

1985 ◽  
Vol 107 (4) ◽  
pp. 378-382 ◽  
Author(s):  
P. H. Meckl ◽  
W. P. Seering
Keyword(s):  
Minimum Energy ◽  
Residual Vibration ◽  
Test Fixture ◽  
Square Wave ◽  
Wave Forcing ◽  
Forcing Function ◽  
Point Motion ◽  
Minimum Residual ◽  
Order Of Magnitude ◽  
Point To Point

This paper describes an appropriately shaped forcing function for moving a dynamic system over an incremental distance with minimum residual vibration. The function is constructed by combining harmonics of a “ramped sinusoid” function so that minimum energy is introduced to the system at its resonant frequencies. A test fixture to evaluate this approach is described and experimental results are given. Residual vibration amplitudes for the ramped sinusoid function are compared with those for a square wave input and a bang-bang function. In practice, the ramped sinusoid achieves nearly an order-of-magnitude reduction in residual vibration amplitude as compared to the square wave forcing function.

Optimal Point-to-Point Motion Control of Robots With Redundant Degrees of Freedom

1986 ◽  
Vol 108 (2) ◽  
pp. 120-126 ◽  
Author(s):  
R. G. Fenton ◽  
B. Benhabib ◽  
A. A. Goldenberg
Keyword(s):  
Motion Control ◽  
Degrees Of Freedom ◽  
Generalized Inverse ◽  
Optimization Procedure ◽  
Merit Function ◽  
Robot Arm ◽  
Optimal Point ◽  
Motion Time ◽  
Point Motion ◽  
Point To Point

Control of a kinematically redundant robot arm requires an optimization procedure to determine the motion of the end effector. The criterion for optimization can be minimum motion time, minimum joint displacement increments or a combined merit function specified according to the requirements of the user. Three different methods may be used to perform the computations and obtain the joint coordinate increments for the point-to-point motion control of the robot. The methods are the “direct,” the “pseudoinverse” and the “generalized inverse” methods. These methods are described in detail in this paper, and results obtained with the three methods are compared on the basis of performing simulated tasks. It is concluded that the generalized inverse method is the most suitable, general method for point-to-point control of robots with more than six degrees-of-freedom.

Experimental evaluation of time-varying impulse shaping with a two-link flexible manipulator

Robotica ◽  
1996 ◽  
Vol 14 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Jung-Keun Cho ◽  
Youn-Sik Park
Keyword(s):  
Vibration Reduction ◽  
Vertical Plane ◽  
Joint Stiffness ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Time Varying ◽  
Modal Properties ◽  
Revolute Joints ◽  
Point Motion ◽  
Point To Point

SUMMARYIn the authors' previous paper,10 an input shaping method was presented to reduce motion-induced vibrations effectively for various classes of flexible systems. In this paper, the effectiveness of the shaping method is experimentally demonstrated with a two-link flexible manipulator systemThe manipulator for experiments includes two revolute joints and two flexible links, and moves on a vertical plane under gravity. An analytic model is developed considering the flexibility of the system and its joint stiffness in order to derive an appropriate estimation of dynamic modal properties. The input shaping method used in this work utilizes time-varying modal properties obtained from the model instead of the conventional input shaping method which employs time-invariant modal properties. A point-to-point motion is tested in order to show the effectivess of the proposed shaping method in vibration reduction during and after a given motion. The given reference trajectories are shaped to suppress the motion induced vibration. The test results demonstrate that the link vibration can be greatly suppressed during and after a motion, and the residual vibration reduction was observed more than 90% by employing this time-varying impulse shaping technique.

Kinematics Analysis and Motion Control of a Mobile Robot Driven by Three Tracked Vehicles

2018 ◽  
Author(s):  
Xin-Jun Liu ◽  
Zhao Gong ◽  
Fugui Xie ◽  
Shuzhan Shentu
Keyword(s):  
Mobile Robot ◽  
Motion Planning ◽  
Degrees Of Freedom ◽  
Inverse Kinematic ◽  
Planning Method ◽  
Tracked Vehicles ◽  
Loop Control ◽  
Point Motion ◽  
Point To Point ◽  
Motion Mode

In this paper, a mobile robot named VicRoB with 6 degrees of freedom (DOFs) driven by three tracked vehicles is designed and analyzed. The robot employs a 3-PPSR parallel configuration. The scheme of the mechanism and the inverse kinematic solution are given. A path planning method of a single tracked vehicle and a coordinated motion planning of three tracked vehicles are proposed. The mechanical structure and the electrical architecture of VicRoB prototype are illustrated. VicRoB can achieve the point-to-point motion mode and the continuous motion mode with employing the motion planning method. The orientation precision of VicRoB is measured in a series of motion experiments, which verifies the feasibility of the motion planning method. This work provides a kinematic basis for the orientation closed loop control of VicRoB whether it works on flat or rough road.

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