Null space motion control of a redundant robot arm using matrix augmentation and saturation method

Hyun Cheol Cho, Jae-Bok Song

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

Implementation of a task using a redundant robot arm requires a solution of the inverse differential kinematic problem. Previous algorithms for this problem used various optimized objective functions to limit null space motion. The problem with using an objective function is that the weight needs to be adjusted according to the type of operation. Since the order of the objective function is lower than that of the kinematic constraints using a pseudo inverse, it is hard to predict null space motion for a repetitive task. This type of problem is said to be manually controlled by the objective function. In this study, we introduce a matrix augmentation method so that active control of the null space motion can be implemented. We use the normal vector of the plane defined by the wrist, elbow and shoulder points and the reference vector Pw-Ps as the control criterion, and we define the output angle between these two vectors. In addition, the saturation method is used to prevent violation of the joint angle limit constraints. A simulation and an experiment using a 7-DOF robot arm were carried out to verify the performance of the proposed algorithm. For the simulation, we used Matlab to generate the null space motion, and we used a 7-DOF robot arm developed in our lab to verify the proposed method experimentally. The proposed algorithm allows redundancy resolution, since intuitive and predictable null space motion can be generated according to a desired output angle.

Original languageEnglish
Title of host publicationMOVIC 2014 - 12th International Conference on Motion and Vibration Control
PublisherJapan Society of Mechanical Engineers
Publication statusPublished - 2014
Event12th International Conference on Motion and Vibration Control, MOVIC 2014 - Sapporo, Hokkaido, Japan
Duration: 2014 Aug 32014 Aug 7

Other

Other12th International Conference on Motion and Vibration Control, MOVIC 2014
CountryJapan
CitySapporo, Hokkaido
Period14/8/314/8/7

Fingerprint

Motion control
Robots
Kinematics
Redundancy
Experiments

Keywords

  • Matrix augmentation
  • Null-space motion control
  • Objective function
  • Output angle
  • Redundant robot arm
  • Saturation method

ASJC Scopus subject areas

  • Control and Systems Engineering

Cite this

Cho, H. C., & Song, J-B. (2014). Null space motion control of a redundant robot arm using matrix augmentation and saturation method. In MOVIC 2014 - 12th International Conference on Motion and Vibration Control Japan Society of Mechanical Engineers.

Null space motion control of a redundant robot arm using matrix augmentation and saturation method. / Cho, Hyun Cheol; Song, Jae-Bok.

MOVIC 2014 - 12th International Conference on Motion and Vibration Control. Japan Society of Mechanical Engineers, 2014.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Cho, HC & Song, J-B 2014, Null space motion control of a redundant robot arm using matrix augmentation and saturation method. in MOVIC 2014 - 12th International Conference on Motion and Vibration Control. Japan Society of Mechanical Engineers, 12th International Conference on Motion and Vibration Control, MOVIC 2014, Sapporo, Hokkaido, Japan, 14/8/3.
Cho HC, Song J-B. Null space motion control of a redundant robot arm using matrix augmentation and saturation method. In MOVIC 2014 - 12th International Conference on Motion and Vibration Control. Japan Society of Mechanical Engineers. 2014
Cho, Hyun Cheol ; Song, Jae-Bok. / Null space motion control of a redundant robot arm using matrix augmentation and saturation method. MOVIC 2014 - 12th International Conference on Motion and Vibration Control. Japan Society of Mechanical Engineers, 2014.
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