Running Robot Research Articles

可変拘束制御を用いた三次元脚式ロボットの走行制御

Several types of running robots have already been studied and developed. But no one of them could perform gradual transition from stationary state to steady hopping or the reverse way. In order to create a three-dimensional running robot, we study a control method called Variable Constraint Control which can realize various kinds of gaits. First we have realized a motion pattern for an one-leg robot which is expressed as differential equations of characteristic values of the robot. It is an unified method for the control of hopping and stationary state. The motion type is easily switched by chaging the parameters of the equations. This paper presents a control method for a one-leg hopping robot, and relation between the parameters and the motion is discussed. A simulation result of it is showed at the end.

2P1-1F-A8 生物規範型四足歩行・走行ロボット「鉄犬 2」

2P1-1F-A8 生物規範型四足歩行・走行ロボット「鉄犬 2」

410 自立型脚式走行ロボットの開発 : 第 2 報 : 実現に向けての検討

410 自立型脚式走行ロボットの開発 : 第 2 報 : 実現に向けての検討

ヒューマノイドのための走行パターンの生成

We propose a method of running pattern generation for a humanoid robot using the dynamics of a simple inverted pendulum. A dynamic simulation using a model of an actual humanoid robot shows that the robot can perform running by applying a generated pattern with slight modifications. From the simulation we evaluate the required performance of actuators for a real running robot.

Controlling a Twister II with VBA and the Zymark ZyRobot ICP

A Visual Basic for Applications program was developed for direct control of a Twister II robot using the Zymark ZyRobot_ICP. Direct control enables automated check-out of the robot, and automated measurement of the plate stacks prior to a robot run. Normal operation of the robot program is performed with just two buttons.

Omni-directional robot and adaptive control method for off-road running

This paper presents an off-road omni-directional mobile robot (OOMR) which can run on an uneven road and obstacles. The robot is constructed with four crawler-roller-motor units and can also be called a "roller-crawler type of omni-directional mobile robot." Each crawler-roller-motor unit can be driven independently and the motion of the robot can be controlled by the speed of each motor. We also designed a position and velocity control system for the robot. The robot can be automatically controlled to run in an optional direction and to track an orbit. We also show the adaptive control method for the OOMR. The efficiency of the mechanism and the control method has been verified by many practical running tests and computer simulations.

606 自立型脚式走行ロボットの開発 : 第 1 報 : シミュレータによる検討

606 自立型脚式走行ロボットの開発 : 第 1 報 : シミュレータによる検討

動物の脚構造をモデル化した１脚走行ロボット Ｋｅｎｋｅｎ

As many biomechanists indicate, tendon plays important role for running or jumping motion. It stores the kinetic energy as a potential energy during stance and also absorbs the impulse at touch down. Inspired by such biomechanical studies, we propose a new simple mechanical model for hindlimb of a dog to realize a robot which imitates dog running, and the hardware design of one-legged running robot, “Kenken” The robot has an articulated leg and uses two hydraulic actuators as muscles and a tensile spring as a tendon. Using an empirical controller based on the characteristic dynamics of the model, the robot has succeeded in planar one-legged running. Although the problem related to the stability at the higher running speed remains, the experimental results demonstrate that the proposed leg mechanism is effective for robotic running.

Control of a robot leg with an adaptive aVLSI CPG chip

The rhythmic locomotion of animals, such as walking, swimming, and flying, is controlled by groups of neurons called central pattern generators (CPGs). CPGs can autonomously produce rhythmic output, but under normal biological conditions make extensive use of peripheral sensory feedback. Models of CPGs have been used to control robot locomotion, but none of these models have incorporated sensory feedback adaptation. We have constructed an adaptive CPG in an analog VLSI chip, and have used the chip to control a running robot leg. We show that adaptation based on sensory feedback permits a stable gait even in an underactuated condition: the leg can be driven using a hip actuator alone while the knee is purely passive.

Design of a Running Robot Based on Motion Analysis of Animals

Design of a Running Robot Based on Motion Analysis of Animals

Self‐Stabilising Quadrupedal Running by Mechanical Design

Dynamic stability allows running animals to maintain preferred speed during locomotion over rough terrain. It appears that rapid disturbance rejection is an emergent property of the mechanical system. In running robots, simple motor control seems to be effective in the negotiation of rough terrain when used in concert with a mechanical system that stabilises passively. Spring‐like legs are a means for providing self‐stabilising characteristics against external perturbations. In this paper, we show that a quadruped robot could be able to perform self‐stable running behaviour in significantly broader ranges of forward speed and pitch rate with a suitable mechanical design, which is not limited to choosing legs spring stiffness only. The results presented here are derived by studying the stability of the passive dynamics of a quadruped robot running in the sagittal plane in a dimensionless context and might explain the success of simple, open loop running controllers on existing experimental quadruped robots. These can be summarised in (a) the self‐stabilised behaviour of a quadruped robot for a particular gait is greatly related to the magnitude of its dimensionless body inertia, (b) the values of hip separation, normalised to rest leg length, and leg relative stiffness of a quadruped robot affect the stability of its motion and should be in inverse proportion to its dimensionless body inertia, and (c) the self‐stable regime of quadruped running robots is enlarged at relatively high forward speeds. We anticipate the proposed guidelines to assist in the design of new, and modifications of existing, quadruped robots. As an example, specific design changes for the Scout II quadruped robot that might improve its performance are proposed.

Legged robots at MIT: what's new since Raibert?

The MIT Leg Lab is best known for the seminal work of Marc Raibert, who showed in the 1980s that robotic running could be accomplished using a few simple, decoupled control laws. Raibert had shown how to calculate the control effort required for the next step of a run based on the results of the previous step, using simple physics-based rules. But smoothly controlling joints in a continuous-time fashion to effect walking seemed more difficult, particularly for non-stead state conditions. It was unclear how to combine passive dynamics with active control. Other researchers were beginning to address robot walking, and the rich diversity of their approaches was very exciting. It thus seemed that walking was the next important area. We embarked on a two-pronged approach: one focusing on making improvements to electromechanical actuators and robot design, the other on walking algorithms and control.

Automated Robotic System for Jet Engine Overhaul. Process Development and Enhancement for Honeycomb Repair.

Following the first phase of system design and development, this paper places the emphasis on the process development and enhancement for the automated honeycomb repair system. In this report, an active force control has been developed for the chiseling process and the optimal parameters have been established for the belt polishing process. The active force control was originally developed to avoid the overload problem on the robot arm, and consequently extended the robot running at its full capacity. The parameter for polishing process was optimized using Taguchi method. As the result, the productivity was improved about 30%-50% and tool life was doubled.

Roller-Crawler Type of Omni-Directional Mobile Robot for Off-Road Running.

This paper presents an Omni Directional Mobile Robot which can run on off road and run over an obstacle. The robot is constructed with four crawler-roller-motor-units and called roller crawler-type of omni-directional mobile Each crawler-reller-motor-unit can be driven independently and the motion of the robot can be controlled by the speed of motors. We also designed a position and velocity control system for the robot. The robot can be automatically controlled to run in optional direction and to track an orbit. The efficiency of the mechanism and the control method has been verified by many practical running tests and computer simulations.

Running in the real world: adjusting leg stiffness for different surfaces.

A running animal coordinates the actions of many muscles, tendons, and ligaments in its leg so that the overall leg behaves like a single mechanical spring during ground contact. Experimental observations have revealed that an animal's leg stiffness is independent of both speed and gravity level, suggesting that it is dictated by inherent musculoskeletal properties. However, if leg stiffness was invariant, the biomechanics of running (e.g. peak ground reaction force and ground contact time) would change when an animal encountered different surfaces in the natural world. We found that human runners adjust their leg stiffness to accommodate changes in surface stiffness, allowing them to maintain similar running mechanics on different surfaces. These results provide important insight into mechanics and control of animal locomotion and suggest that incorporating an adjustable leg stiffness in the design of hopping and running robots is important if they are to match the agility and speed of animals on varied terrain.

Stable control of a simulated one-legged running robot with hip and leg compliance

We present a control strategy for a simplified model of a one-legged running robot which features compliant elements in series with hip and leg actuators. For this model, proper spring selection and initial conditions result in operation close to the desired motion, without any actuation. However, this motion is not stable. Our controller is based on online calculations of the desired passive dynamic motion which is then parametrized in terms of a normalized locomotion time. We show in simulation that the proposed controller stabilizes a wide range of velocities and is robust to modeling errors. It also tracks changes in desired robot velocity and remains largely passive despite a fixed set of springs, masses, and inertias. Comparisons of simulated runs with direct hip actuation show 95% hip actuation energy savings at 3 m/s. Such energy savings are critical for the power autonomy of electrically actuated legged robots.

Motion and Structure from Significant Segments in Man Made Environments

An algorithm to determine the camera motion and the structure in a 3D man made environment is proposed. The algorithm is based on straight edges extracted in the image and some plentiful geometrical relations between them (verticality, horizontality, parallelism, perpendicularity). In this paper the computation of motion and structure using these constraints is tackled. The information of the tips of the straight edges are also used to determine motion. Some partial results using two images are now available. Its application to a mobile robot running in man made environments could be considered.

An Implicit Approach for a Mobile Robot Running on a Force Field without Generation of Local Minima

The artificial potential approach is good and elegant one to plan a robot path from a start point to a goal point while avoiding the obstacles in the workspace. However, one potential approach constructs its potential field with several local minima, and consequently the robot may stop at one of the local minima until it arrives at the goal point (the global minimum). Another potential approach eliminates the local minima from its potential field in order to move surely the robot at the goal point, and consequently it requires much calculation time to build such a good potential field by a hard pre-processing.For this point of view, we propose a similar approach to plan a robot path between start and goal points surely. This approach defines implicitly a force field Without generation of local minima by an easy pre-processing, and thus let the robot arrive at the goal point easily and certainly. As a result, our approach can be useful for a path-planning one in a works pace whose allocation of the obstacles and the goal point is altered very often.

Three Uses for Springs in Legged Locomotion

Running animals and robots can save energy and reduce unwanted heat production by bouncing along on springs, using the principle of the pogo stick. (The principal springs in animals are tendons.) They can make further energy savings by using return springs to halt the legs at the end of each foward or backward swing and start them swinging the other way. The forces at impact of feet with the ground can be moderated by compliant foot pads, which can improve road holding by preventing "chatter" (vibrations in which the foot repeatedly leaves and returns to the ground before settling). Animals use springs in all three ways but there seems to be a need for more use of springs in legged robots, especially in robots designed to run fast.