Industrial Robot: An International Journal A generic walking pattern generation method for humanoid robot walking on the slopes Article information (original) (raw)

Pattern generation for bipedal walking on slopes and stairs

2008

Uneven terrain walking is one of the key challenges in bipedal walking. In this paper, we propose a motion pattern generator for slope walking in 3D dynamics using preview control of zero moment point (ZMP). In this method, the future ZMP locations are selected with respect to known slope gradient. The trajectory of the center of mass (CoM) of the robot is generated by using the preview controller to maintain the ZMP at the desired location. Two models of slope walking, namely upslope and downslope, are investigated. Continuous walking on slopes with different gradients is also studied to enable the robots to walk on uneven terrains. Since staircase walking is similar to slope walking, the slope walking trajectory generator can also be applied to the staircase walking. Simulation results show that the robot can walk on many types of slopes and stairs by using the proposed pattern generator.

A pattern generator of humanoid robots walking on a rough terrain using a handrail

2008

This paper presents a motion pattern generator of humanoid robots that walks on a flat plane, steps and a rough terrain. It is guaranteed rigorously that the desired contact between a humanoid robot and terrain should be maintained by keeping the contact wrench sum between them inside the contact wrench cone under the sufficient friction assumption. A walking pattern is generated by solving the contact wrench equations and by applying the resolved momentum control.

A Pattern Generator of Humanoid Robots Walking on a Rough Terrain

2007

This paper presents a motion pattern generator of humanoid robots that walks on a flat plane, steps and a rough terrain. It is guaranteed rigorously that the desired contact between a humanoid robot and terrain should be maintained by keeping the contact wrench sum between them inside the contact wrench cone under the sufficient friction assumption. A walking pattern is generated by solving the contact wrench equations and by applying the resolved momentum control.

Command State-Based Modifiable Walking Pattern Generation on an Inclined Plane in Pitch and Roll Directions for Humanoid Robots

IEEE/ASME Transactions on Mechatronics, 2011

Previous research related to walking on an inclined plane for humanoid robots, including the 3-D linear inverted pendulum model (3D-LIPM) approach, were unable to modify walking period, step length, and walking direction independently without any additional step for adjusting the center of mass (CoM) motion. Moreover, the inclination along the pitch direction was only considered for walking. To solve these problems, a novel command state (CS)-based modifiable walking pattern generator for humanoid robots is proposed for modifiable walking on an inclined plane in both pitch and roll directions. The dynamic equation of the 3D-LIPM on the inclined plane in both pitch and roll directions is derived to obtain the CoM motion. Using the CoM motion, a method for modifiable walking pattern generation on the inclined plane is developed to follow a given CS composed of walking periods, step lengths, and walking directions for both legs. The effectiveness of the proposed walking pattern generator is demonstrated through both simulation and experiment for the small-sized humanoid robot, HanSaRam-IX (HSR-IX). Index Terms-3-D linear inverted pendulum model (3D-LIPM), command state (CS), humanoid robot, modifiable walking pattern generator (MWPG), walking on inclined plane, zero-moment point (ZMP).

Modular Architecture for Humanoid Walking Pattern Prototyping and Experiments

Advanced Robotics, 2008

In this paper we describe the use of design patterns as a basis for creating a Humanoid Walking Pattern Generator Software having a modular architecture. This architecture made possible the rapid porting of several novel walking algorithms on a full size humanoid robot HRP-2. The body of work currently available allows extracting a general software architecture usable with inter-exchange between simulations and real experiments. The proposed architecture with the associated design patterns are described together with several applications: a pattern generator for a HRP-2 with passive toe-joints, a pattern for dynamically stepping over large obstacles, and a new quadratic problem (QP) formulation for the generation of the reference ZMP. Thanks to the versatility and the modularity of the proposed framework, the QP method has been implemented and experienced within four days only.

A walking pattern generation method with feedback and feedforward control for humanoid robots

2009 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2009

This paper proposes a new walking pattern generation method for humanoid robots. The proposed method consists of feedforward control and feedback control for walking pattern generation. The pole placement method as a feedback controller changes the poles of system in order to generate more stable and smoother walking pattern. The advanced pole-zero cancelation by series approximation(PZCSA) as a feedforward controller plays a role of reducing the inherent property of linear inverted pendulum model (LIPM), that is, non-minimum phase property due to an unstable zero of LIPM and tracking efficiently the desired zero moment point (ZMP). The efficiency of the proposed method is verified by three simulations such as arbitrary walking step length, arbitrary walking phase time and sudden change of walking path.

Walking pattern generation for a humanoid robot with compliant joints

Autonomous Robots, 2013

This work presents a walking pattern generator based on the control of the center of mass (COM) states and its experimental validations on the compliant humanoid robot COMAN powered by intrinsically compliant joints. To cope with the inaccuracies of the joint position tracking resulted by the physical compliance, the proposed pattern generator uses the feedback states of the COM and on-line computes the updated COM references. The position and velocity of the COM are the state variables, and the constrained ground reaction force (GRF) limited by the support polygon is the control effort to drive the real COM states to track the desired references. The frequency analysis of the COM demonstrates its low frequency spectrum that indicates the demand of a low control bandwidth which is suitable for a robot system with compliant joints. The effectiveness of the proposed gait generation method was demonstrated by the experiments performed on the COMAN robot. The experimental data such as the COM position and velocity tracking, the GRF applied on feet, the measured step length and the walking velocity are analyzed. The effect of the passive compliance is also discussed.

An Open Loop Walking on Different Slopes for NAO Humanoid Robot

Procedia Engineering, 2012

Dynamic gait planning for humanoid robots encounters difficulties such as stability, speed, and smoothness. In most of previous studies, joints' trajectories are calculated in 3D Cartesian space, then, introducing boundary conditions and using polynomials, the first and second derivatives of the motion are ensured to be continuous. Then, the stability of the motion is guaranteed using Zero Moment Point (ZMP) stability criterion. In this study, a trajectory planner is presented using the semi-ellipse equations of the motion; the continuity of the derivatives is preserved. Stabilization of motion is attained through using ZMP criterion and 3d inverted pendulum equations in three slope conditions. The effectiveness of the proposed approach is investigated using Webots software. Implementing proposed approach, smoothness, stability, and convenient speed (rather than 17 cm/s in flat condition) are achieved.