Multiple Impedance Control of Hybrid Parallel-Serial Manipulator for Object Manipulation Task

Section: 
Research
Subsection: 
Thesis
Place: 
Department of Mechanical Engineering
K.N. Toosi University of Technology (KNTU)
Tehran (Iran)
Associate: 
A. Nasr
S.A.A. Moosavian
Date: 
2014/09/21 to 2016/01/22

One of the widely used of industrial robots is Object Manipulation (OM). Recently, Cable Driven Parallel Robot (CDPR) has a very large workspace suitable for this application. However, there are possible cable collisions with the environment. Therefore, use of a Serial Manipulator (SM) recommended penetrating the blind spots. Thus, the combination of CDPR-SM is recommended for OM. The tasks of OM like welding, surface finishing, cleaning and so on need algorithms capable of determining the interaction force and position control. In addition, constrained and suspended structure of CDPR is evaluated and the best structure for the control and construction is selected.

Firstly, kinematics modeling of CDPR and SM systems provided. As a detail, topics such as inverse kinematics, Jacobian formula, speed relation, acceleration analysis, singularity and sensitive of CDPR investigated. Also, other issue such as forward, inverse kinematics, speed, acceleration, Jacobian, singularities and workspace analysis of SM checked and presented.

secondly, dynamics modeling which is useful in control subjects, simulation and analysis system, extracted. More precisely, the SM dynamics obtained by iterative Newton-Euler and CDPR dynamics modeled by Newton-Euler method. Beside that, an algorithm to optimize traction of cable and a redundancy resolution algorithm are also provided. Surprisingly, a new method proposed to reduce the redundancy of actuators. Eventually, models of dynamics and kinematics verified by a virtual model which is provided in Simulink of Matlab.

Since, structure of CDPR is highly important in cable parallel robots, it optimized by criteria such as controllable workspace, free singularity workspace, sensitivity and stiffness equipped with SM.

Moreover, multiple impedance control (MIC) used to OM in the presence of external disturbances discussed for OM. However, workspace and joint space unite impedance is also checked. Parallel and serial MIC algorithm by different coefficient proposed and implemented. Furthermore, coefficients of MIC optimised according to optimizing error and wrench criteria by GA.

The CDPR wich discussed in this thesis for implementing control algorithms and study performance is manufactured. According to the analysis, mechanical components of the robot have been designed and manufactured. In addition, electronic platform prepared in order to send control commands. The platform position data obtained by a new method that combines machine vision and forward kinematic. Forward kinematics by an artificial neural network that is trained for all situations in the workspace obtained. At the same time, dual camera detect the marked platform.

Task: 

  • Proposing a Hybrid Cable Parallel-Serial Manipulator for Object Manipulation in presence of human in industrial enviroment
  • Inverse, Forward Kinematic, Velocity, Acceleration, Workspace Mathematical Modelling and Validation by SimMechanics Virtual Software Model of Hybrid System and Cable
  • Dynamic Modelling, Redundancy Resolution Algorithm, Reduce Cable Redundancy by Mechanical Novelty of CDPR and Dynamic Modelling of Cable
  • Structural Design Optimization of a Constraint and Suspended Parallel Robot according to Stiffness, Sensitivity, Singularity, Workspace Volume Analysis by Genetic Algorithm
  • Proposing Algorithm and Implementation of Serial and Parallel Multiple Impedance Control for Object Manipulation, Optimization of Impedance Coefficients to Manage Interaction of Human-Robot Force/Moment
  • Design and Manufacturing of 8 Cable Constraint Parallel Robot, Providing Image Processing (Vision) + IMU for Position/Orientation Feedback, Proposing Algorithm in Shortage of Rotary Winch Sensor, Implementing Nonlinear Position Control Loop of Platform