Investigating balance control of a hopping bipedal robot

Legged robots are dynamic moving machines that are potentially able to traverse through rough terrain which is inaccessible for wheeled or tracked vehicles. For bipedal robots, balancing control while hopping/running is challenging, especially when the foot contact area is small. Servo hydraulics is highly suitable for robot leg actuation due to its high power density and good power-to weight ratio. This paper presents a controller for a hydraulically actuated bipedal robot, the Bath Bipedal Hopper (BBH). The controller follows the well-established structure of the ‘Three-part’ control algorithm. The three parts are: hopping height control; longitudinal velocity control by changing the leg angle during the flight phase to place the foot in the desired position; and body attitude correction during the stance phase. Simulation results from a detailed non-linear model indicate that this controller can successfully balance the hydraulic robot while hopping with different longitudinal velocities

Energy-Tank based Force Control for 3D Contour Following

Manipulation has been a major topic in robotics since its earlier developments. In the last few years, a new research area has focused in the introduction of manipulation capabilities on mobile robots. Several challenges are faced when mobile robots interact with unknown environments, for which inherent compliance is a key feature to achieve the intended outcome in a safe and robust way. This paper proposes a unified method of force control with energy-tank based methods to tackle 3D contour following. This method is tailored for manipulators that are designed for aerial applications, and addresses the interaction with unknown surfaces by also tackling the safety aspect, i.e. the response generated during contact loss

Sensors for mobile robots

Mobile robots represent a new generation of automation. Technologies developed for industrial robots in the field of Production Automation are still being generalized for application outside the factories. Mobility is a characteristic feature for this kind of robots assigned for a lot of different applications extending from space to underwater purpose, from construction to agriculture and from mining to fire fighting. A key element to obtain this ambitious goal is sensor-quidance. More intelligent controllers which need sensor input for their autonomous route planning and navigation will be used. This paper gives a survey of sensor tasks for mobile robots, of basic possibilities for sensor principles and contains some remarks how to use them. Finally, some remarks how to use them. Finally, some examples for complete sensor combinations to guide mobile robots are presented. (IPA

The significance of leg mass in modeling quadrupedal running gaits

Abstract. In modeling running gaits of biological and robotic quadrupeds, leg mass is often neglected. Analysis of the system angular momentum in a biological model and a robot model indicates that including leg mass is significant in capturing the roll motion in trotting and pacing. Leg mass has a more significant effect on the pitch motion in bounding and is most critical in accurately capturing the dynamics of galloping.

Impedance Control of an Industrial Manipulator in a Dual Arm Assembly Cell

: This paper addresses the problem of the "right hand" control in dual arm assembly cell. While considering the constraints and perturbations that occur during a typical multi-robot assembly task (poorly known and varying environment parameters, mobile obstacles, impacts, friction, noises,...), a controller have been developed in [1]. It is based on an impedance controller which is an intermediate solution between a fully decoupled scheme ([2]) and a linearized scheme. To increase the performances of the resulting controller, a higher control level is added to modify on-line the desired impedance and/or the reference trajectory. This supervisor has been developed using fuzzy logic techniques. The choice of gains to ensure stability is discussed, considering some theorical and practical aspects. Experimental results, obtained on a two-arms assembly system, illustrate the ability of the system to absorb large external impacts. 1 Introduction Advanced assembly applications sometimes re..