Vahid Johari Majd

About

Vahid Johari Majd is a leading researcher in nonlinear control and robotics, with a focus on the robust and fault-tolerant control of legged systems. His work is defined by pioneering advances in finite-time control theory and its application to quadruped robots. Majd’s most cited paper (63 citations) introduced a novel recursive singularity-free Fast Terminal Sliding Mode (FTSM) strategy, solving the long-standing singularity problem in finite-time tracking for nonholonomic systems. He has made substantial contributions to quadruped robot locomotion, developing model-based backstepping controllers for bounding motion, MPC-based push recovery algorithms for trotting gaits, and nonlinear disturbance observers for sensor-less estimation of external ground forces. A key theme in his research is actuator fault tolerance; he has designed robust adaptive force-position controllers that maintain stable motion even under time-varying actuator faults and saturation. His work on fractional-order active fault-tolerant control and prescribed-performance intelligent controllers further demonstrates his leadership in ensuring robot safety and reliability. With over 250 total citations, Majd’s research bridges advanced control theory and practical robotics, offering powerful solutions for high-performance, resilient legged locomotion.

Research Focus

Key Achievements

Top Papers

1. 1
   A finite-time tracker for nonholonomic systems using recursive singularity-free FTSM

   63 citations · 2011
2. 2
   An MPC-based two-dimensional push recovery of a quadruped robot in trotting gait using its reduced virtual model

   42 citations · 2019
3. 3
   Fractional-order active fault-tolerant force-position controller design for the legged robots using saturated actuator with unknown bias and gain degradation

   41 citations · 2017
4. 4
   Modeling and robust backstepping control of an underactuated quadruped robot in bounding motion

   34 citations · 2012
5. 5
   Estimation of external forces acting on the legs of a quadruped robot using two nonlinear disturbance observers

   18 citations · 2016
6. 6
   Observer‐based robust adaptive force‐position controller design for quadruped robots with actuator faults

   13 citations · 2018
7. 7
   Dynamic-free robust adaptive intelligent fault-tolerant controller design with prescribed performance for stable motion of quadruped robots

   11 citations · 2019
8. 8
   Sliding-Mode Tracking Control of a Walking Quadruped Robot with a Push Recovery Algorithm Using a Nonlinear Disturbance Observer as a Virtual Force Sensor

   10 citations · 2019
9. 9
   Analysis and Design of a Time-Varying Extended State Observer for a Class of Nonlinear Systems with Unknown Dynamics Using Spectral Lyapunov Function

   9 citations · 2018
10. 10
    Improving the stability of gait planning for quadruped robots

    8 citations · 2014

Key Collaborators

Contact & Links