Mechanical recognition of unknown environment using active/passive contact motion

Ryogo Kubo, Kouhei Ohnishi

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)


This paper presents a method to determine contact conditions between a planar end-effector and the environment, i.e., face-to-face, face-to-line, or face-to-point contact. First of all, two kinds of contact motion of a planar end-effector, i.e., passive and active contact motions, are described. A compliance controller is implemented to achieve the passive contact motion, and the "groping motion"is generated as the active contact motion. Then, novel robot-friendly expressions of the environment are proposed based on the concept of environmental modes. Discrete Fourier transform matrices are utilized as matrices transforming environmental information into environmental modes. In the experiments, a planar end-effector contacts with the environment with the passive and active contact motions, and the environmental data obtained from sensors are transformed into environmental modes. The profiles of the extracted environmental modes are utilized to determine the contact conditions. The validity of the proposed method is confirmed by the experimental results.

Original languageEnglish
Pages (from-to)1364-1374
Number of pages11
JournalIEEE Transactions on Industrial Electronics
Issue number5
Publication statusPublished - 2009


  • Compliance control
  • DFT
  • Discrete fourier transform (DFT)
  • Disturbance observer
  • Disturbance observer (DOB)
  • Environment recognition
  • Environmental mode
  • Haptics

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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