Publications by Salman Faraji | EPFL Graph Search

A Dynamical System Approach for Adaptive Grasping, Navigation and Co-Manipulation with Humanoid Robots

Aude Billard, Salman Faraji, Nadia Barbara Figueroa Fernandez, Mikhail Koptev

In this paper, we present an integrated approach that provides compliant control of an iCub humanoid robot and adaptive reaching, grasping, navigating and co-manipulating capabilities. We use state-dependent dynamical systems (DS) to (i) coordinate and dri ...

IEEE2020

Scalable closed-form trajectories for periodic and non-periodic human-like walking

Auke Ijspeert, Salman Faraji

We present a new framework to generate humanlike lower-limb trajectories in periodic and non-periodic walking. In our method, walking dynamics is encoded in 3LP, a linear simplified model composed of three pendulums to simulate falling, swing, and torso ba ...

IEEE2019

Bipedal walking and push recovery with a stepping strategy based on time-projection control

Auke Ijspeert, Seyed Hamed Razavi, Salman Faraji

In this paper, we present a simple control framework for online push recovery on biped robots with dynamic stepping properties. Owing to relatively heavy legs in our humanoid robot COMAN, we use a linear model called 3LP, which is composed of three pendulu ...

SAGE PUBLICATIONS LTD2019

From standing balance to walking: A single control structure for a continuum of gaits

Auke Ijspeert, Seyed Hamed Razavi, Salman Faraji

This article presents a control algorithm framework with which a bipedal robot can perform a variety of gaits by only modifying a small set of control parameters. The controller drives a number of variables, called non-emergent variables, to their desired ...

2019

Modeling robot geometries like molecules, application to fast multi-contact posture planning for humanoids

Auke Ijspeert, Salman Faraji

Traditional joint-space models used to describe equations of motion for humanoid robots offer nice properties linked directly to the way these robots are built. However, from a computational point of view and convergence properties, these models are not th ...

Ieee-Inst Electrical Electronics Engineers Inc2018

Fast multi-contact whole-body motion planning with limb dynamics

Auke Ijspeert, Jonathan Patrick Arreguit O'Neill, Salman Faraji

We present a new method for multi-contact motion planning which efficiently encodes internal dynamics of the robot without needing to use full models. Our approach is based on a five-mass model which is formulated by Cartesian points instead of joint angle ...

IEEE2018

A simple model of mechanical effects to estimate metabolic cost of human walking

Auke Ijspeert, Salman Faraji, Amy Roning Wu

Since the advent of energy measurement devices, gait experiments have shown that energetic economy has a large influence on human walking behavior. However, few cost models have attempted to capture the major energy components under comprehensive walking c ...

Nature Research2018

Imprecise dynamic walking with time-projection control

Philippe Müllhaupt, Auke Ijspeert, Salman Faraji

We present a new walking foot-placement controller based on 3LP, a 3D model of bipedal walking that is composed of three pendulums to simulate falling, swing and torso dynamics. Taking advantage of linear equations and closed-form solutions of the 3LP mode ...

2018

An Overview on Principles for Energy Efficient Robot Locomotion

Salman Faraji

Despite enhancements in the development of robotic systems, the energy economy of today's robots lags far behind that of biological systems. This is in particular critical for untethered legged robot locomotion. To elucidate the current stage of energy eff ...

FRONTIERS MEDIA SA2018

Towards Robust Bipedal Locomotion : From Simple Models To Full-Body Compliance

Salman Faraji

Thanks to better actuator technologies and control algorithms, humanoid robots to date can perform a wide range of locomotion activities outside lab environments. These robots face various control challenges like high dimensionality, contact switches durin ...

EPFL2018

Singularity-tolerant inverse kinematics for bipedal robots: An efficient use of computational power to reduce energy consumption

Auke Ijspeert, Salman Faraji

We propose a nonlinear inverse kinematics formulation which solves for positions directly. Compared to various other popular methods that integrate velocities, this formulation can better handle fast, asymmetric and singular-postured balancing tasks for hu ...

Ieee-Inst Electrical Electronics Engineers Inc2017

3LP: a linear 3D-walking model including torso and swing dynamics

Auke Ijspeert, Salman Faraji

In this paper, we present a new mechanical model for biped locomotion, composed of three linear pendulums (one per leg and one for the whole upper body) to describe stance, swing and torso dynamics. In addition to a double support phase, this model has dif ...

Sage Publications Ltd2017

A singularity-tolerant inverse kinematics including joint position and velocity limitations

Auke Ijspeert, Salman Faraji

Humanoid robots have many degrees of freedom which ideally enables them to accomplish different tasks. From a control viewpoint, however, the geometric complexity makes planning and control difficult. Favoring controllability properties, it is popular to o ...

2017

Designing a virtual whole body tactile sensor suit for a simulated humanoid robot using inverse dynamics

Auke Ijspeert, Salman Faraji

In this paper, we propose a novel architecture to estimate external forces applied to a compliantly controlled balancing robot in simulations. We use similar dynamics equations used in the controller to find mismatches in the available sensory data and ass ...

Ieee2016

Practical considerations in using inverse dynamics on a humanoid robot: torque tracking, sensor fusion and Cartesian control laws

Auke Ijspeert, Luca Colasanto, Salman Faraji

Although considering dynamics in the control of humanoid robots can improve tracking and compliance in agile tasks, it requires local and global states of the system, precise torque control and proper modeling. In this paper we discuss practical issues to ...

2015

Versatile and robust 3D walking with a simulated humanoid robot (Atlas): A model predictive control approach

Auke Ijspeert, Soha Pouya, Salman Faraji

IEEE2014

Robust and Agile 3D Biped Walking With Steering Capability Using a Footstep Predictive Approach

Auke Ijspeert, Soha Pouya, Salman Faraji

In this paper, we formulate a novel hierarchical controller for walking of torque controlled humanoid robots. Our method uses a whole body optimization approach which generates joint torques, given Cartesian accelerations of different points on the robot. ...

2014

The effect of fractionality nature in differences between computer simulation and experimental results of a chaotic circuit

Salman Faraji

In practice, some differences are usually observed between computer simulation and experimental results of a chaotic circuit. In this paper, it is tried to obtain computer simulation results having more correlation with those obtained in practice by using ...

Versita2013

Compliant and adaptive control of a planar monopod hopper in rough terrain

Auke Ijspeert, Rico Möckel, Soha Pouya, Salman Faraji

IEEE2013