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.
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.
Humanoid robot walking control on inclined planes
2011 IEEE International Conference on Mechatronics, 2011
The humanoid bipedal structure is suitable for a assitive robot functioning in the human environment. However, the bipedal walk is a difficult control problem. Walking just on even floor is not satisfactory for the applicability of a humanoid robot. This paper presents a study on bipedal walk on inclined planes. A Zero Moment Point (ZMP) based reference generation technique is employed. The orientation of the feet is adjusted online by a fuzzy logic system to adapt to different walking surface slopes. This system uses a sampling time larger than the one of the joint space position controllers. The average value of the body pitch angle is used as the inputs to the fuzzy logic system. A foot pitch orientation compensator implemented independently for the two feet complements the fuzyy controller. A 12-degrees-of-freedom (DOF) biped robot model is used in the full-dynamics 3-D simulations. Simulations are carried out on even floor and inclined planes with different slopes. The results indicate that the control method presented is successful in enabling the robot to climb slopes of 8.5 degrees (15 percent grade).
Kinodynamic planning for humanoid robots walking on uneven terrain
2009
For the purpose of realizing the humanoid robot walking on uneven terrain, this paper proposes the kinodynamic gait planning method where both kinematics and dynamics of the system are considered. We can simultaneously plan both the foot-place and the wholebody motion taking the dynamical balance of the robot into consideration. As a dynamic constraint, we consider the differential equation of the robot's CoG. To solve this constraint, we use a walking pattern generator. We randomly sample the configuration space to search for the path connecting the start and the goal configurations. To show the effectiveness of the proposed methods, we show simulation and experimental results where the humanoid robot HRP-2 walks on rocky cliff with hands contacting the environment.
The Rh-1 full-size humanoid robot: Design, walking pattern generation and control
Applied Bionics and Biomechanics, 2009
This paper is an overview of the humanoid robot Rh-1, the second phase of the Rh project, which was launched by the Robotics Lab at the Carlos III University of Madrid in 2002. The robot mechanical design includes the specifications development in order to construct a platform, which is capable of stable biped walking. At first, the robots' weights were calculated in order to obtain the inverse dynamics and to select the actuators. After that, mechanical specifications were introduced in order to verify the robot's structural behaviour with different experimental gaits. In addition, an important aspect is the joints design when their axes are crossed, which is called 'Joints of Rectangular Axes' (JRA). The problem with these joints is obtaining two or more degrees of freedom (DOF) in small space. The construction of a humanoid robot also includes the design of hardware and software architectures. The main advantage of the proposed hardware and software architectures is the use of standardised solutions frequently used in the automation industry and commercially available hardware components. It provides scalability, modularity and application of standardised interfaces and brings the design of the complex control system of the humanoid robot out of a closed laboratory to industry. Stable walking is the most essential ability for the humanoid robot. The three dimensional Linear Inverted Pendulum Model (3D-LIPM) and the Cart-table models had been used in order to achieve natural and dynamic biped walking. Humanoid dynamics is widely simplified by concentrating its mass in the centre of gravity (COG) and moving it following the natural inverted pendulum laws (3D-LIPM) or by controlling the cart motion (Cart-table model). An offline-calculated motion pattern does not guarantee the walking stability of the humanoid robot. Control architecture for the dynamic humanoid robot walking was developed, which is able to make online modifications of the motion patterns in order to adjust it to the continuously changing environment. Experimental results concerning biped locomotion of the Rh-1 humanoid robot are presented and discussed.
A walking pattern generator for biped robots on uneven terrains
2010 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2010
We present a new method to generate biped walking patterns for biped robots on non-horizontal or uneven terrains. Our formulation uses a universal stability criterion that checks whether the resultant of the gravity wrench and the inertia wrench of a robot lies in the convex cone of the wrenches resulting from contacts between the robot and the environment. We present an algorithm to compute the feasible acceleration of the robot's CoM (center of mass) and use that algorithm to generate biped walking patterns. Our approach is more general and applicable to uneven terrains as compared with prior methods based on the ZMP (zero-moment point) criterion. We highlight its applications on some benchmarks.
Journal of Intelligent and Robotic Systems, 2019
This study addresses optimal walking pattern generation for SURENA III humanoid robot in a stair-climbing scenario. To this end, the kinematic configuration of the 31-DOF humanoid robot is studied. Integrating the detailed dynamic properties of the robot, a comprehensive and precise dynamic model is developed for its lower-limb. In order to generate the optimal walking pattern for the considered humanoid robot, trajectories for feet and pelvis are first designed, and then joint angles are derived by means of inverse kinematics. Such a complete model provides the designer with the necessary tools to optimize the trajectory generation. Using two different types of objective functions, namely joints maximum torque and overall energy consumption, several optimization processes have been carried out to account for different stair-climbing speeds as well as different stair heights. Subsequently, the optimal walking patterns are obtained by applying the Genetic Algorithm (GA). The simulation results are verified experimentally by implementing the proposed walking patterns on SURENA III, a humanoid robot designed and fabricated in CAST (Center of Advanced Systems and Technologies). This paper provides insight into how an optimized gait for climbing stairs can be realized for a human-size humanoid robot from two different viewpoints and at several walking speeds and stair heights by assuming each stair as a virtual slope.
Pattern Generation of Biped Walking Constrained on Parametric Surface
2005
This paper describes a generation method for spatially natural biped walking. By limiting the COG (Center of Gravity) motion space to a sculptured surface, the degree of freedom of the COG matches to the number of the ZMP (Zero Moment Point) equations. The COG motion can be uniquely generated along a specified surface satisfying the ZMP constraint with low calculation cost. Spatial and time parts are separable by representing motion surface of the COG as parametric variables. The motion surface defines the relative height of the COG from the landing foot position. Thus, the proposed method reflects geometric information directly to the motion planning without considering walk stability.
Walking machines - initial testbeds, first industrial applications and new research
Computing & Control Engineering Journal, 1997
Walking locomotion theory has been drastically improved during the last decade and now the technology seems to be ready for industrial applications. More than 60 different climbing and walking machines developed in research laboratories and universities have been catalogued, but industrial applications are emerging very slowly. This article covers some of the activity and production run at the Institute for Industrial Automation (CSIC) related to development of prototypes for both research purposes and industrial applications as well. he Department of Automatic Control at the Institute for Industrial Automation (IAI), Madrid, Spain, has been developing robotic T systems for more than 15 years. At the end of the 1980s, the department became interested in the research and development of walking machines as innovative locomotion systems for industrial applications. Over recent years, we have developed several walking robots for both basic research and industrial application purposes. This article describes walking machine research and development carried out at the IAI. Basically, it focuses on describing: the
Walking patterns for real time path planning simulation of humanoids
2012 IEEE RO-MAN: The 21st IEEE International Symposium on Robot and Human Interactive Communication, 2012
We present here a detailed description of the walking algorithm that was designed for 3D simulation of locomotion and path planning of humanoid robots. The walking patterns described were implemented on NAO humanoid models that are used in the 3D simulation league of RoboCup to play soccer. The locomotion algorithm is based on the well known 3D-LIP model that consists of defining walking primitives of the center of mass, keeping its height constant and assuming no torque at the support foot. This paper proposes to detail how to connect the walking primitives, especially at the start of the walk. The second added value of this work resides in the rotation walking primitives that are generated differently from the linear translation walking primitives. This enables the robot to achieve fast rotation on the spot or about a center located on the longitudinal axis. The paper also addresses the issue of re-entrance, i.e. how to take into account a new walking request in real time without waiting for the end of the current walk.