Development of the Non-Contact Torque Sensor for EPAS Using Maluss Polarization Law

Malus의 편광법칙을 이용한 EPAS용 비접촉 torque sensor 개발

  • Roh, Byung-Ok (Dept.of Industry Engineering, Sunmoon University) ;
  • Park, Ho (Dept.of Automotive, Chonan National Junior Technology College) ;
  • Kang, Pan-Shik
  • 노병옥 (선문대학교 산업공학과) ;
  • 박호 (천안공업대학 자동차공학과) ;
  • 강판식 (선문대학교 대학원 기계공학과)
  • Published : 2001.07.01


Among the automotive steering systems, an Electric Power Assisted steering (EPAS) system utilizes an electronically controlled electric motor to provide steering assistance to the driver. The key components of the EPAS system are torque sensor, ECU (Electronic Control Unit), and DC Motor. The most important component of the EPAS is the torque sensor. The conventional torque sensor has complicated mechanical mechanism of torque detection. However, we suggest a non-contact torque sensor for EPAS using Maluss polarization law. It was found that the sensor exhibited not only excellent linearity but also superior characteristics of hysteresis, temperature and vibration.


Electric Power Assisted Steering;Polarizer;Analyzer;Torque Sensor;Torsion Bar;Polarization;Beam Splitter


  1. Yasuo Shimizu, Mitsutaka Sugino, Toshitake Dawai, Tersuya Matsumoto, 1991, '電動パワステアリングについて,' 自動車技術, Vol. 45, No. 10
  2. Reed, G., 1989, 'Torque Measurement in Rotating Shafts the Optical Alternatives,' Des. Eng.(May). pp. 69-72
  3. 윤석찬, 왕영용, 한창수, 2000, 'Ball Screw 형 전동식 동력 조향장치의 제어에 관한 연구,' 한국자동차공학회논문집, 한국자동차공학회, 제 8 권 제 1호, pp. 124-134
  4. 선우면호, 1997, 자동차와 전기. 전자기술, '97 한국자동차공학회 추계학술대회,' pp. 323-328
  5. Nakayama, T. and Suda, E., 1990, 'The Present of Electic Power Steering,' JSAE Rev., 11, pp. 62-68
  6. Zabler, E., Dukart, A., Heintz, F. and Krott, R., 1994, 'A Non-Contact Strain-Gage Torque Sensor for Automative Servo-Driven Steering System,' Sensor and Actuators A, pp. 41-42
  7. Takahi Nakayama and Eiichi Suda, 1990, 'Present and Future of Electric Power Steering,' 自動車技術, Vol. 44, No. 1, pp. 106-111
  8. Hazelden, R.J., 1993, 'Optical Torque Sensor for Automotive Steering System,' Sensor and Actuators A, pp. 37-38, pp. 193-197