Detection of three-axis angles by an optical sensor

Yusuke Saito, Yoshikazu Arai, Wei Gao

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)


This article describes an optical method for measurement of three-axis angles (roll angle ΔθX, pitch angle ΔθY, yaw angle ΔθZ). The laser autocollimation method is improved from two-axis angle measurement to three-axis angle measurement by employing a diffraction grating instead of a plane mirror as the target reflector. The three-axis angle components can be calculated by three methods of using different diffraction light spots reflected from the diffraction grating. Method 1 uses three beams, which are the 0th-order and the ±1st-order diffraction light spots. Both Method 2 and Method 3 use two light spots. The former uses the ±1st-order diffraction light spots and the latter combines the 0th-order with the +1st-order or the -1st-order diffraction light spots. A prototype three-axis angle sensor is also designed and fabricated to compare the characteristics of the three methods from the viewpoints of sensitivity, linearity and resolution of the sensor output.

Original languageEnglish
Pages (from-to)175-183
Number of pages9
JournalSensors and Actuators, A: Physical
Issue number2
Publication statusPublished - 2009 Mar 25


  • Angular motion error
  • Diffraction grating
  • Laser autocollimation method
  • Pitch angle
  • Roll angle
  • Three-axis angle sensor
  • Yaw angle

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering


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