A novel approach for humanoid push recovery using stereopsis

Robotica ◽  
2013 ◽  
Vol 32 (3) ◽  
pp. 413-431 ◽  
Author(s):  
Mohammad-Ali Nikouei Mahani ◽  
Shahram Jafari ◽  
Hadi Rahmatkhah
Keyword(s):  
Mathematical Model ◽  
Humanoid Robot ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Critical Issue ◽  
Acceleration Sensor ◽  
Deviation Angle ◽  
Push Recovery ◽  
Novel Approach ◽  
Angle Stable

SUMMARYPush recovery is one of the most challenging problems for the current humanoid robots. The importance of push recovery can be well observed in the real environment. The critical issue for a humanoid is to maintain and recover its balance against any disturbances. In this research a new stereovision approach is proposed to estimate the robot deviation angle and consequently, the movement of center of mass of the robot is calculated. Then, two novel strategies have been devised to recover the balance of the humanoid which are called “knee strategy” and “knee-hip strategy.” Also, a mathematical model validates the efficiency of the proposed strategies as demonstrated in the paper. Experiments have been conducted on a humanoid robot and demonstrate that the predicted robot deviation angle, using stereovision technique, converges to the actual deviation angle. Stable regions of proposed strategies illustrate that the humanoid can recover its stability in a robust manner. Vision-based estimation also shows a higher correlation to actual deviation angle and a lower fluctuation compared with the output of the acceleration sensor.

On the Manipulability of the Center of Mass of Humanoid Robots: Application to Design

2010 ◽  
Author(s):  
Sebastien Cotton ◽  
Philippe Fraisse ◽  
Andrew P. Murray
Keyword(s):  
Humanoid Robot ◽  
Mechanical Design ◽  
Dynamic Balance ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Contact Forces ◽  
Joint Torque ◽  
Contact Points ◽  
Floating Base ◽  
Space Formulation

This paper proposes an analysis of the manipulability of the Center of Mass (CoM) of humanoid robots. Starting from the dynamic equations of humanoid robots, the operational space formulation is used to express the dynamics of humanoid robots at their CoM and under their specific characteristics: a free-floating base, forces at contact points, and dynamic balance constraints. After a review of the kinematic manipulability of the CoM, the concept of dynamic manipulability of the CoM is introduced. The latter represents the ability of a humanoid robot to generate a spatial motion under a stability criterion. The size and shape of the dynamic manipulability of the CoM are a function of the joint torque limitations, the contact forces and the zero moment point used as a stability criteria. Two calculations of the CoM dynamic manipulability are proposed, a fast ellipsoid approximation, and the exact polyhedron computation. A case study illustrates the proposed approach on the HOAP3 humanoid robot and its use for mechanical design optimization.

Humanoid adaptive locomotion control through a bioinspired CPG-based controller

Robotica ◽  
2021 ◽  
pp. 1-18
Author(s):  
Chenpeng Yao ◽  
Chengju Liu ◽  
Li Xia ◽  
Ming Liu ◽  
Qijun Chen
Keyword(s):  
Control Strategy ◽  
Sensory Feedback ◽  
Humanoid Robot ◽  
A Priori ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Pattern Generator ◽  
Gait Planning ◽  
Adaptive Gait ◽  
Walking Adaptability

Abstract To achieve adaptive gait planning of humanoid robots, a hierarchical central pattern generator (H-CPG) model with a basic rhythmic signal generation layer and a pattern formation layer is proposed to modulate the center of mass (CoM) and the online foot trajectory. The entrainment property of the CPG is exploited for adaptive walking in the absence of a priori knowledge of walking conditions, and the sensory feedback is applied to modulate the generated trajectories online to improve walking adaptability and stability. The developed control strategy is verified using a humanoid robot on sloped terrain and shows good performance.

Dynamic walking of humanoid robot on flat surface using amplified LIPM plus flywheel model

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abhishek Kumar Kashyap ◽  
Dayal R. Parhi
Keyword(s):  
Humanoid Robot ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Dynamic Walking ◽  
Turning Angle ◽  
Content Type ◽  
Walking Behavior ◽  
Walking Gait ◽  
Ant Lion Optimization ◽  
Travel Length

PurposeHumanoid robots have complicated dynamics, and they lack dynamic stability. Despite having similarities in kinematic structure, developing a humanoid robot with robust walking is quite difficult. In this paper, an attempt to produce a robust and expected walking gait is made by using an ALO (ant lion optimization) tuned linear inverted pendulum model plus flywheel (LIPM plus flywheel).Design/methodology/approachThe LIPM plus flywheel provides the stabilized dynamic walking, which is further optimized by ALO during interaction with obstacles. It gives an ultimate turning angle, which makes the robot come closer to the obstacle and provide a turning angle that optimizes the travel length. This enhancement releases the constraint on the height of the COM (center of mass) and provides a larger stride. The framework of a sequential locomotion planer has been discussed to get the expected gait. The proposed method has been successfully tested on a simulated model and validated on the real NAO humanoid robot.FindingsThe convergence curve defends the selection of the proposed controller, and the deviation under 5% between simulation and experimental results in regards to travel length and travel time proves its robustness and efficacy. The trajectory of various joints obtained using the proposed controller is compared with the joint trajectory obtained using the default controller. The comparison shows the stable walking behavior generated by the proposed controller.Originality/valueHumanoid robots are preferred over mobile robots because they can easily imitate the behaviors of humans and can result in higher output with higher efficiency for repetitive tasks. A controller has been developed using tuning the parameters of LIPM plus flywheel by the ALO approach and implementing it in a humanoid robot. Simulations and experiments have been performed, and joint angles for various joints are calculated and compared with the default controller. The tuned controller can be implemented in various other humanoid robots

Motion and Gesture Compliance Control for High Performance of a Wheeled Humanoid Robot

2017 ◽  
Author(s):  
Salvador Rojas ◽  
He Shen ◽  
Holly Griffiths ◽  
Ni Li ◽  
Lanchun Zhang
Keyword(s):  
High Performance ◽  
Humanoid Robot ◽  
Control Method ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Euler Method ◽  
Mobile Platforms ◽  
Compliance Control

Humanoid robots have the potential to help or even take the place of humans working in extreme or undesirable environments. Wheeled humanoids are robots that combine the mobility of mobile platforms, and the dexterity of an articulated body with two robotic arms. To perform like a human being, these robots normally are designed with a high center of mass, which makes it challenging to maintain stability while achieving high performance on complex and unpredictable terrain. Inspired from how humans react to balance themselves, a compliance control method is studied to help the wheeled humanoid robot developed at the Robotics Laboratory at Cal State LA achieve high dynamic performance while scouting over uneven terrain. Lagrange-Euler method is used to obtain the dynamic model of the humanoid robot. Then a nonlinear sliding mode compliance controller is derived and proven to ensure asymptotic stability of the humanoid robot while tracking desired reference trajectories. Finally, the performance of the proposed compliance control system is demonstrated using simulation. The results show that the robot successfully tracks a given input while maintaining balance based on the proposed tip-over avoidance algorithm.

scholarly journals Capture Steps: Robust Walking for Humanoid Robots

2019 ◽  
Vol 16 (06) ◽  
pp. 1950032 ◽  
Author(s):  
Marcell Missura ◽  
Maren Bennewitz ◽  
Sven Behnke
Keyword(s):  
Degrees Of Freedom ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Open Loop ◽  
Bipedal Walking ◽  
Foot Placement ◽  
Inverted Pendulum Model ◽  
Push Recovery ◽  
Pendulum Model ◽  
Walking Velocity

Stable bipedal walking is a key prerequisite for humanoid robots to reach their potential of being versatile helpers in our everyday environments. Bipedal walking is, however, a complex motion that requires the coordination of many degrees of freedom while it is also inherently unstable and sensitive to disturbances. The balance of a walking biped has to be constantly maintained. The most effective ways of controlling balance are well timed and placed recovery steps — capture steps — that absorb the expense momentum gained from a push or a stumble. We present a bipedal gait generation framework that utilizes step timing and foot placement techniques in order to recover the balance of a biped even after strong disturbances. Our framework modifies the next footstep location instantly when responding to a disturbance and generates controllable omnidirectional walking using only very little sensing and computational power. We exploit the open-loop stability of a central pattern generated gait to fit a linear inverted pendulum model (LIPM) to the observed center of mass (CoM) trajectory. Then, we use the fitted model to predict suitable footstep locations and timings in order to maintain balance while following a target walking velocity. Our experiments show qualitative and statistical evidence of one of the strongest push-recovery capabilities among humanoid robots to date.

Humanoid gait generation in complex environments based on template models and optimality principles learned from human beings

2018 ◽  
Vol 37 (10) ◽  
pp. 1184-1204 ◽  
Author(s):  
Debora Clever ◽  
Yue Hu ◽  
Katja Mombaur
Keyword(s):  
Optimal Control ◽  
Motion Capture ◽  
Humanoid Robot ◽  
Center Of Mass ◽  
Humanoid Robots ◽  
Human Motion ◽  
Human Beings ◽  
Inverse Optimal Control ◽  
Gait Generation ◽  
Template Model

In this paper, we present an inverse optimal control-based transfer of motions from human experiments to humanoid robots and apply it to walking in constrained environments. To this end, we introduce a 3D template model, which describes motion on the basis of center-of-mass trajectory, foot trajectories, upper-body orientation, and phase duration. Despite its abstract architecture, with prismatic joints combined with damped series elastic actuators instead of knees, the model (including dynamics and constraints) is suitable for describing both human and humanoid locomotion with appropriate parameters. We present and apply an inverse optimal control approach to identify optimality criteria based on human motion capture experiments. The identified optimal strategy is then transferred to a humanoid robot template model for gait generation by solving an optimal control problem, which takes into account the properties of the robot and differences in the environment. The results of this step are the center-of-mass trajectory, the foot trajectories, the torso orientation, and the single and double support phase durations for a sequence of steps, allowing the humanoid robot to walk within a new environment. In a previous paper, we have already presented one computational cycle (from motion capture data to an optimized robot template motion) for the example of walking over irregular stepping stones with the aim of transferring the motion to two very different humanoid robots (iCub@Heidelberg and HRP-2@LAAS). This study represents an extension, containing an entirely new part on the transfer of the optimized template motion to the iCub robot by means of inverse kinematics in a dynamic simulation environment and also on the real robot.

Effects of COM Vertical Oscillation on Joint Torques During 3D Walking of Humanoid Robots

2016 ◽  
Vol 13 (04) ◽  
pp. 1650019 ◽  
Author(s):  
Sahab Omran ◽  
Sophie Sakka ◽  
Yannick Aoustin
Keyword(s):  
Humanoid Robot ◽  
Inverted Pendulum ◽  
Center Of Mass ◽  
Vertical Motion ◽  
Humanoid Robots ◽  
Dynamics Simulation ◽  
Vertical Oscillation ◽  
Human Beings ◽  
Joint Torques ◽  
Consequent Reduction

This paper proposes an analysis of the effect of vertical motion of the center of mass (COM) during humanoid walking. The linear inverted pendulum (LIP) model is classically used to deal with humanoid balance during walking. The effects on energy consumption of the COM height remaining constant for humanoid robots, or varying like human beings are studied here. Two approaches are introduced for the comparison: the LIP which offers the great advantage of analytical solving (i.e., fast and easy calculations), and a numerical solving of the IP dynamics, which allows varying the height of the center of mass during walking. The results are compared using a sthenic criterion in a 3D dynamics simulation of the humanoid robot Romeo (Aldebaran Robotics Company) and show a consequent reduction of the robot torque solicitation when the COM oscillates vertically.

TO THE STABILITY OF TANK VEHICLES IN THE BRAKE MODE

2019 ◽  
pp. 27-32
Author(s):  
Denys Popelysh ◽  
Yurii Seluk ◽  
Sergyi Tomchuk
Keyword(s):  
Mathematical Model ◽  
Control Systems ◽  
Distribution Systems ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Center Of Mass ◽  
Dynamic Processes ◽  
Course Stability ◽  
The Stability ◽  
Tank Vehicles

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.

Humans and humanoids

2018 ◽  
Author(s):  
Giorgio Metta
Keyword(s):  
Humanoid Robot ◽  
Robot Vision ◽  
Physical Space ◽  
Humanoid Robots ◽  
Human Robot Interaction ◽  
Biologically Inspired ◽  
Robot Interaction ◽  
Humanoid Robotics ◽  
Biomimetic Robot ◽  
Compliant Actuation

This chapter outlines a number of research lines that, starting from the observation of nature, attempt to mimic human behavior in humanoid robots. Humanoid robotics is one of the most exciting proving grounds for the development of biologically inspired hardware and software—machines that try to recreate billions of years of evolution with some of the abilities and characteristics of living beings. Humanoids could be especially useful for their ability to “live” in human-populated environments, occupying the same physical space as people and using tools that have been designed for people. Natural human–robot interaction is also an important facet of humanoid research. Finally, learning and adapting from experience, the hallmark of human intelligence, may require some approximation to the human body in order to attain similar capacities to humans. This chapter focuses particularly on compliant actuation, soft robotics, biomimetic robot vision, robot touch, and brain-inspired motor control in the context of the iCub humanoid robot.

DESIGN AND SIMULATION OF A 1-DOF ANTHROPOMORPHIC CLUTCHED ARM FOR HUMANOID ROBOTS

2010 ◽  
Vol 07 (01) ◽  
pp. 157-182 ◽  
Author(s):  
HAO GU ◽  
MARCO CECCARELLI ◽  
GIUSEPPE CARBONE
Keyword(s):  
Humanoid Robot ◽  
Humanoid Robots ◽  
Robot Arm ◽  
Dynamic Simulations ◽  
Suitable Combination ◽  
User Friendly

In this paper, problems for an anthropomorphic robot arm are approached for an application in a humanoid robot with the specific features of cost oriented design and user-friendly operation. One DOF solution is proposed by using a suitable combination of gearing systems, clutches, and linkages. Models and dynamic simulations are used both for designing the system and checking the operation feasibility.

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