Robotics & Control Research

University of Tehran (2014–2017)

During my Master's at the Human & Robot Interaction Lab (TaarLab), I led R&D initiatives spanning telerobotics, control theory, and mechatronic design.

1. Telerobotics, Shared Control & Motion Planning

Project: Shared-control of a Mobile Robot via Haptic Feedback

This project addressed the challenge of operating mobile robots in dynamic environments where time delays and obstacles compromise safety. I developed a shared-control architecture where a human operator controls the robot via a haptic device, but the robot's autonomy (Motion Planning) intervenes to avoid collisions.

  • Motion Planning: Developed a geometric-based motion planning algorithm (Receding Horizon Control) that navigates unknown environments.
  • Key Innovation: Synergized impedance control with convex optimization to blend human input with autonomous safety constraints.
  • Outcome: The system successfully navigated dynamic environments with moving obstacles.
Phase Trajectory Comparison

Figure: Schematic of deployed teleoperation.

Experimental validation of the shared-control framework avoiding dynamic obstacles.

Experimental validation of the motion planning for a single mobile robot.

Relevant Publications:

  • M. Zarei, N. Kashi, M. Tale Masouleh, A. Kalhor, "Experimental Study on Shared-control of a Mobile Robot with a Haptic Device by a Synergy of Receding Horizon, Convex Optimization and Impedance Control Concept," Journal of Intelligent & Robotic Systems, 2020. (Featured on Cover)
  • M. Zarei, et al., "Experimental study on optimal motion planning of wheeled mobile robot using convex optimization and receding horizon concept."
  • M. Zarei, et al., "An optimal motion planning and obstacle avoidance algorithm based on the finite time velocity obstacle approach."

2. Non-Linear Control Theory

Project: Oscillation Damping & Arc Length Method

We introduced a novel mathematical concept—the Arc Length Function—to estimate the Domain of Attraction (DA) for non-linear control systems. By minimizing the arc length of the system's phase trajectory, we could design controllers that significantly reduced oscillation.

  • Contribution: Proved that minimizing trajectory length correlates with faster settling times and reduced overshoot.
  • Application: Validated on cable-driven parallel robots and haptic devices to suppress unwanted vibrations.
Phase Trajectory Comparison

Figure: Estimated DoA for different nonlinear systems.

Experimental oscillation damping controller for cable parallel robots.

Experimental oscillation damping controller for delta parallel robots.

Relevant Publications:

  • M. Zarei, A. Kalhor, D. Brake, "Arc length based maximal Lyapunov functions and domains of attraction estimation for polynomial nonlinear systems," Automatica, 2018.
  • M. Zarei, A. Aflakian, A. Kalhor, M. Tale Masouleh, "Oscillation damping of nonlinear control systems based on the phase trajectory length concept," Mechanism and Machine Theory, 2018.
  • M. Zarei, A. Kalhor, M. Tale Masouleh, "An experimental phase trajectory length based oscillation damping impedance control for Novint Falcon haptic device," Journal of Mechanical Engineering Science, 2018.
  • S. Ansari-Rad, M. Zarei, et al., "Stabilization of a two-dof spherical parallel robot via a novel adaptive approach," International Conference on Robotics and Mechatronics, 2018.

3. Virtual Reality Dentistry Simulator

Project: National Grand Project for Dental Training

I served as a lead control and CAD engineer for a national initiative to build a haptic-enabled VR dentistry trainer. The goal was to allow dental students to "feel" the difference between tooth enamel, decay, and gum tissue during virtual drilling procedures.

  • Role: Designed the mechanical structure of the haptic stylus and implemented the control loops.
  • Tech Stack: C++, SolidWorks, Haptic Rendering Algorithms.
Haptic Device End Effectors

Figure: Modified end effectors of the haptic device.

Virtual reality environment for dentistry training.

Relevant Publications:

  • N. Karbasizadeh, M. Zarei, A. Aflakian, M. Tale Masouleh, A. Kalhor, "Experimental dynamic identification and model feed-forward control of Novint Falcon haptic device," Mechatronics, 2018.

4. Parallel Robot Design

Project: Design and Manufacture of the ThesseraTaar/QuattroTaar Robot

We designed and operationalized a novel parallel robot. Parallel robots offer high precision and speed but are complex to control due to their closed-loop kinematics. This project involved the full lifecycle from optimal mechanical design to fabrication and control.

  • Achievement: Successfully patented the mechanical design. The robot featured a unique kinematic structure optimized for pick-and-place operations.
  • Work: Performed kinematic analysis, mechanical manufacturing, and real-time control implementation using ABC and PSO algorithms.

Designed and manufactured robot in action.

Relevant Publications:

  • M. Zarei, et al., "Optimal design and fabrication of a 4-dof quattrotaar parallel robot with singularity-free workspace by ABC and PSO algorithms."