Control of Active Stereo Vision System based on piezo-actuators


Piezo-Motor Control, Visual Servoing, Real-Time



For purposive robots in a complex and dynamic world, the most basic visual functions required are target detection, fixation and tracking. A fast and accurate active vision system with wide field of view is necessary for finding important targets around the robot. In our Institute we have developed an active stereo-gaze platform (see the picture) which is a compact and light weight.

The stereo-systems is composed of 2 Cameras Firewire 1493a, 3 DOF per eye driven by Linear Piezo-Motors with incremental encoders. The eyes are controlled by a standard PID position control for the Linear motors without real feedback of eye orientation.

Tasks and Objectives

In this thesis the student will implement a robust non-linear control for the piezo-actuators of each eye. The communication interface for the piezo-actuators is based on a FPGA. The control framework will be implemented on a Linux Workstation. The main objectives of this thesis are:

  1. Non-Linear Position Control for the piezo-actuators with friction compensation
  2. Piezo-actuators Modeling
  3. Design an Observer based on the robot model
  4. Visual Feedback calibration of the Observer


  • FPGA programming skills
  • strong background on C++ (preferable under Linux)
  • Programming in Matlab