Planning Continuous-Jerk Trajectories for Industrial Manipulators

2012 ◽  
Author(s):  
Paolo Boscariol ◽  
Alessandro Gasparetto ◽  
Renato Vidoni
Keyword(s):  
Industrial Robot ◽  
Robotic Manipulators ◽  
Initial Time ◽  
Optimal Time ◽  
Polynomial Functions ◽  
Industrial Manipulators ◽  
Order Polynomial ◽  
Planning Methods ◽  
Cartesian Manipulator ◽  
Robotic Applications

Planning smooth trajectories is crucial in the most advanced robotic applications in industrial environments. In this paper two novel trajectory planning methods for robotic manipulators are introduced, named “545” and “5455”. Both methods are based on an interpolation of a sequence of via points using a combination of 4th and 5th order polynomial functions. These techniques allow to obtain a continuous-jerk trajectory for improved smoothness and minimum excitation of vibration. By using the “545” method, null jerk at initial time can be achieved, while with the “5455” method one can impose an arbitrary value of jerk at both the first and the last via-point. The outcome of both methods is the optimal time distribution of the via points, with respect to a predefined objective function. Results are provided for a 3 d.o.f. Cartesian manipulator, but the techniques may be applied to any industrial robot.

Jerk-Continuous Trajectories for Cyclic Tasks

2012 ◽  
Author(s):  
Paolo Boscariol ◽  
Alessandro Gasparetto ◽  
Renato Vidoni
Keyword(s):  
Optimization Algorithm ◽  
Execution Time ◽  
Robotic Manipulators ◽  
Polynomial Functions ◽  
End Effector ◽  
Industrial Manipulator ◽  
Repetitive Tasks ◽  
Order Polynomial ◽  
Planning Methods ◽  
Robotic Applications

Planning smooth trajectories is a crucial task for most advanced robotic applications. Poorly planned trajectories can be inefficient under many aspects, since they might require long execution time and induce unnecessary vibration on the end-effector of the robot as well as high solicitation on its mechanical structure and actuators. In this paper a novel trajectory planning methods for robotic manipulators is introduced, named “5455”. This method is based on an interpolation of a sequence of via points using a combination of 4th and 5th order polynomial functions. This technique allows to obtain a continuous-jerk trajectory for improved smoothness and minimum excitation of vibration. Such method allows also to impose an arbitrary value of jerk at the first and last via-point. This feature can be effectively used to produce a smooth trajectory for repetitive tasks, trough an innovative optimization algorithm which is introduced in this paper. Both numerical and experimental results are provided for a 3 d.o.f. Cartesian robot, but the techniques provided here can be applied to any industrial manipulator.

Implementation of Adaptive Techniques for Motion Control of Robotic Manipulators

1988 ◽  
Vol 110 (1) ◽  
pp. 62-69 ◽  
Author(s):  
M. Tomizuka ◽  
R. Horowitz ◽  
G. Anwar ◽  
Y. L. Jia
Keyword(s):  
Adaptive Control ◽  
Industrial Robot ◽  
Robotic Manipulators ◽  
Adaptive Controller ◽  
Test Stand ◽  
Experimental Results ◽  
Direct Drive ◽  
Adaptive Controllers ◽  
Friction Forces ◽  
Digital Implementation

This paper is concerned with the digital implementation and experimental evaluation of two adaptive controllers for robotic manipulators. The first is a continuous time model reference adaptive controller, and the second is a discrete time adaptive controller. The primary purpose of these adaptive controllers is to compensate for inertial variations due to changes in configuration and payload, as well as disturbances, such as Coulomb friction and/or gravitational forces. Experimental results are obtained from a laboratory test stand, which emulates an one-axis direct drive robot arm with variable inertia, as well as a Toshiba TSR-500V industrial robot. Experimental results from the test stand indicate that these adaptive control schemes are promising for the control of direct drive robot arms. Friction forces arising from the harmonic gear of the Toshiba robot were detrimental if not properly compensated. Because of a high gearing ratio, the advantage of adaptive control for the Toshiba arm could be shown only by detuning the controller.

Optimization in the Design and Control of Robotic Manipulators: A Survey

1989 ◽  
Vol 42 (4) ◽  
pp. 117-128 ◽  
Author(s):  
S. S. Rao ◽  
P. K. Bhatti
Keyword(s):  
Optimal Control ◽  
Robot Manipulator ◽  
Research Effort ◽  
Industrial Robot ◽  
Load Capacity ◽  
Robotic Manipulators ◽  
Optimization Techniques ◽  
Highly Nonlinear ◽  
Manipulator Design ◽  
And Control

Robotics is a relatively new and evolving technology being applied to manufacturing automation and is fast replacing the special-purpose machines or hard automation as it is often called. Demands for higher productivity, better and uniform quality products, and better working environments are primary reasons for its development. An industrial robot is a multifunctional and computer-controlled mechanical manipulator exhibiting a complex and highly nonlinear behavior. Even though most current robots have anthropomorphic configurations, they have far inferior manipulating abilities compared to humans. A great deal of research effort is presently being directed toward improving their overall performance by using optimal mechanical structures and control strategies. The optimal design of robot manipulators can include kinematic performance characteristics such as workspace, accuracy, repeatability, and redundancy. The static load capacity as well as dynamic criteria such as generalized inertia ellipsoid, dynamic manipulability, and vibratory response have also been considered in the design stages. The optimal control problems typically involve trajectory planning, time-optimal control, energy-optimal control, and mixed-optimal control. The constraints in a robot manipulator design problem usually involve link stresses, actuator torques, elastic deformation of links, and collision avoidance. This paper presents a review of the literature on the issues of optimum design and control of robotic manipulators and also the various optimization techniques currently available for application to robotics.

A Method of Inverse Kinematics Solution for a Class of Robotic Manipulators

1997 ◽  
Author(s):  
Tuna Balkan ◽  
M. Kemal Özgören ◽  
M. A. Sahir Arikan ◽  
H. Murat Baykurt
Keyword(s):  
Nonlinear Equation ◽  
Analytical Method ◽  
Multiple Solutions ◽  
Inverse Kinematics ◽  
Industrial Robot ◽  
Robotic Manipulators ◽  
Inverse Kinematic ◽  
Singular Configurations ◽  
Inverse Kinematics Problem ◽  
Joint Variable

Abstract A semi-analytical method and a computer program are developed for inverse kinematics solution of a class of robotic manipulators, in which four joint variables are contained in wrist point equations. For this case, it becomes possible to express all the joint variables in terms of a joint variable, and this reduces the inverse kinematics problem to solving a nonlinear equation in terms of that joint variable. The solution can be obtained by iterative methods and the remaining joint variables can easily be computed by using the solved joint variable. Since the method is manipulator dependent, the equations will be different for kinematically different classes of manipulators, and should be derived analytically. A significant benefit of the method is that, the singular configurations and the multiple solutions indicated by sign ambiguities can be determined while deriving the inverse kinematic expressions. The developed method is applied to a six-revolute-joint industrial robot, FANUC Arc Mate Sr.

Walk-through programming for robotic manipulators based on admittance control

Robotica ◽  
2013 ◽  
Vol 31 (7) ◽  
pp. 1143-1153 ◽  
Author(s):  
Luca Bascetta ◽  
Gianni Ferretti ◽  
Gianantonio Magnani ◽  
Paolo Rocco
Keyword(s):  
Robot Control ◽  
Industrial Robot ◽  
Robotic Manipulators ◽  
Programming System ◽  
Admittance Control ◽  
Safety Issues ◽  
Safety Strategies ◽  
Programming Techniques ◽  
Tool Centre Point ◽  
Safety Limit

SUMMARYThe present paper addresses the issues that should be covered in order to develop walk-through programming techniques (i.e. a manual guidance of the robot) in an industrial scenario. First, an exact formulation of the dynamics of the tool the human should feel when interacting with the robot is presented. Then, the paper discusses a way to implement such dynamics on an industrial robot equipped with an open robot control system and a wrist force/torque sensor, as well as the safety issues related to the walk-through programming. In particular, two strategies that make use of admittance control to constrain the robot motion are presented. One slows down the robot when the velocity of the tool centre point exceeds a specified safety limit, the other one limits the robot workspace by way of virtual safety surfaces. Experimental results on a COMAU Smart Six robot are presented, showing the performance of the walk-through programming system endowed with the two proposed safety strategies.

Gait Trajectory Planning Based on Least Squares Fitting - Polynomial for Lower Extremity Rehabilitation

2014 ◽  
Vol 668-669 ◽  
pp. 1569-1572
Author(s):  
Fu Cheng Cao ◽  
Li Min Du
Keyword(s):  
Data Analysis ◽  
Lower Extremity ◽  
Least Squares ◽  
Trajectory Planning ◽  
Curve Fitting ◽  
Polynomial Functions ◽  
Computer Data ◽  
Normal Gait ◽  
Order Polynomial ◽  
Least Squares Curve Fitting

According to the analysis results of normal gait data, a method of gait trajectory planning based least squares curve fitting is proposed. Given the generalized-th order polynomial functions, the coefficients for functions are determined, then, a health hip and knee gait trajectory planning functions were obtained. The computer data analysis results show that the gait trajectory fitted can represent a normal gait accurately.

scholarly journals Modelling the temperature in joint friction of industrial manipulators

Robotica ◽  
2017 ◽  
Vol 37 (5) ◽  
pp. 906-927 ◽  
Author(s):  
Luca Simoni ◽  
Manuel Beschi ◽  
Giovanni Legnani ◽  
Antonio Visioli
Keyword(s):  
Parameter Estimation ◽  
Temperature Sensor ◽  
Industrial Robot ◽  
Friction Torque ◽  
Dynamic Friction ◽  
New Model ◽  
Joint Friction ◽  
Experimental Campaign ◽  
Industrial Manipulators ◽  
Simplifying Assumptions

SummaryIn this paper, a new model for joint dynamic friction of industrial robot manipulators is presented. In particular, the effects of the temperature in the joints are considered. A polynomial-based model is proposed and the parameter estimation is performed without the need of a joint temperature sensor. The use of an observer is then proposed to compensate for the uncertainty in the initial estimation of the temperature value. A large experimental campaign show that the model, in spite of the simplifying assumptions made, is effective in estimating the joint temperature and therefore the friction torque during the robot operations, even for values of velocities that have not been previously employed.

scholarly journals DESIGN OF INDUSTRIAL ROBOT FOR METAL DRILLING

2019 ◽  
Vol 1 (02) ◽  
pp. 103-112
Author(s):  
Dinesh kumar A
Keyword(s):  
Mechanical Properties ◽  
Industrial Robot ◽  
Drilling Process ◽  
The Novel ◽  
Programming Techniques ◽  
The Cost ◽  
Robotic Applications

The latest advancements in the programming techniques combined with the novel visionary and the motion technologies intensifying the possibility of the robotic applications. Nowadays the use of Robots in the industries mainly for the purpose of drilling, grinding and grating are very much increased. But due to the measurement variation’s along the different axes based on the physical and the mechanical properties of the material and the stiffness problems found in the Robots there prevails certain errors causing the modifications in the positioning. So the proposed process in the paper concentrates on the enhancing the stiffness of the robots and bring down the labors in the drilling process in order to have an optimized output at a reduced cost. The proposed design shows improvement in the accuracy and the efficiency of the robot working with the minimized rejection loss and the cost of the end product.

Efficient Singularity-Free Workspace Approximations Using Sum-of-Squares Programming

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Wankun Sirichotiyakul ◽  
Volkan Patoglu ◽  
Aykut C. Satici
Keyword(s):  
Quadratic Forms ◽  
Optimization Technique ◽  
Robotic Manipulators ◽  
Additional Constraint ◽  
Sum Of Squares ◽  
Type I ◽  
Polynomial Functions ◽  
Type Ii ◽  
Trigonometric Functions ◽  
Outer Approximations

Abstract In this paper, we provide a general framework to determine inner and outer approximations to the singularity-free workspace of fully actuated robotic manipulators, subject to Type-I and Type-II singularities. This framework utilizes the sum-of-squares optimization technique, which is numerically implemented by semidefinite programming. In order to apply the sum-of-squares optimization technique, we convert the trigonometric functions in the kinematics of the manipulator to polynomial functions with an additional constraint. We define two quadratic forms, describing two ellipsoids, whose volumes are optimized to yield inner and outer approximations of the singularity-free workspace.

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