Motion Generation and Control for the Pneumatic Biped "Lucy"

Verrelst, Björn; Vermeulen, Jimmy; Vanderborght, Bram; Ham, Ronald Van; Naudet, Joris; Lefeber, Dirk; Daerden, F.; Damme, Michaël Van

doi:10.1142/s0219843606000655

Cited by 15 publications

(14 citation statements)

References 10 publications

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“…Lucy (Fig. 1, [14]) has been built to have a testbench for evaluating Pleated Pneumatic Artificial Muscles (PPAM, [15]) used for bipedal walking machines. A pneumatic artificial muscle is essentially a membrane that expands radially and contracts axially when inflated, while generating high pulling forces along the longitudinal axis.…”

Section: Bipedal Walking Robot Lucymentioning

confidence: 99%

Treadmill walking of the pneumatic biped Lucy: Walking at different speeds and step-lengths

et al. 2008

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Actuators with adaptable compliance are gaining interest in the field of legged robotics due to their capability to store motion energy and to exploit the natural dynamics of the system to reduce energy consumption while walking and running. To perform research on compliant actuators we have built the planar biped Lucy. The robot has six actuated joints, the ankle, knee and hip of both legs with each joint powered by two pleated pneumatic artificial muscles in an antagonistic setup. This makes it possible to control both the torque and the stiffness of the joint. Such compliant actuators are used in passive walkers to overcome friction when walking over level ground and to improve stability. Typically, this kind of robots is only designed to walk with a constant walking speed and step-length, determined by the mechanical design of the mechanism and the properties of the ground. In this paper, we show that by an appropriate control, the robot Lucy is able to walk at different speeds and step-lengths and that adding and releasing weights does not affect the stability of the robot. To perform these experiments, an automated treadmill was built Keywords: bipedal walking robot, pneumatic artificial muscle 1. Introduction. Bipedal robots are gaining interest because of their potential for higher mobility than that of wheeled vehicles. Although for an outsider in the field walking is very obvious, the fastest robot at the moment is Asimo with a top running speed of 6 km/h. A study on humanoid robots performed by FZI [1] forecasts that it will take about 10-20 years before bipeds can even with humans. The best-known humanoid robots are Asimo [2], Qrio [3], and HRP-2 [4], all actuated by classical electric drives. Nowadays, research is performed to develop soft or compliant actuators and implement them in bipeds. A study of the control system of robots in which soft actuators were used can be found in [5] for a sagittal hopping robot, [6, 7] for a 3D hopping robot, and [8] for a walking biped. Other publications [9][10][11][12] can be noted, in which the problems of control of similar systems are considered. Main reason is to reduce the energy consumption of those robots by exploiting the natural dynamics of the system. The "Passive walkers" do not even need actuation at all to walk down a sloped surface or only use a limited amount of actuation when walking over level ground just enough to overcome friction. Examples are the Cornell biped, the Delft biped Denise, and MIT robot Toddler [13]. Unfortunately, they are of little practical use. They have difficulties to start, cannot change their speed, and cannot stop, contrary to a completely actuated robot. Adding control while exploiting the natural dynamics of the system will be probably the optimal. The way we want to find this optimal is by using actuators with controllable compliance just like humans do.As compliant or soft actuator we propose the Pleated Pneumatic Artificial Muscle for which an elaborate control has been developed. The control of such actuator is new....

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Section: Bipedal Walking Robot Lucymentioning

confidence: 99%

Treadmill walking of the pneumatic biped Lucy: Walking at different speeds and step-lengths

et al. 2008

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“…Thus, taking the motion of the upper body into account and not keeping it at a fixed angle as is the case in this paper. The effectiveness of this method applied to the robot "Lucy" has been proven in simulation (Verrelst et al, 2006). The joint trajectory tracking controller is divided into three parts, analogously as for the pendulum structure: the computed torque module, the delta-p unit and the bang-bang pressure controller.…”

Section: Robot Controlmentioning

confidence: 99%

“…The disadvantage is that these results are discontinue when switching between single and double support phase. A discussion on this implementation has been done by means of simulations (Verrelst et al, 2006). An alternative way to distribute torques over the actuators is to make a linear transition of torques between the old and new single support phase, by calculating the applied torque as if the robot is in single support phase.…”

Section: Robot Controlmentioning

confidence: 99%

“…So the inertial influence is rather small compared to the gravitational component of the controller. The controller has however already performed well under dynamic walking situation in simulation (Verrelst et al, 2006). Several movies of the walking motion of the biped "lucy" can be seen at the following website: http://lucy.vub.ac.be.…”

Section: Walking Experimentsmentioning

confidence: 99%

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Novel Robotic Applications using Adaptable Compliant Actuation. An Implementation Towards Reduction of Energy Consumption for Legged Robots

Verrelst¹,

Vanderborght²

2006

Mobile Robotics, Moving Intelligence

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“…Dirk et al built a planar walking biped robot Lucy [6]. Each joint of Lucy, driven by two PAMs in antagonistic setup, is actively controlled, enabling it to walk at different speeds and step-lengths on a treadmill [7,8]. However, this robot only uses monoarticular muscles, making it different with human lower limbs which incorporate both monoarticular and biarticular muscles.…”

Section: Introductionmentioning

confidence: 99%

Design and control of a pneumatic musculoskeletal biped robot

Zang

Liu²,

Liu³

et al. 2016

THC

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Abstract. BACKGROUND: Pneumatic artificial muscles are quite promising actuators for humanoid robots owing to their similar characteristics with human muscles. Moreover, biologically inspired musculoskeletal systems are particularly important for humanoid robots to perform versatile dynamic tasks. OBJECTIVE: This study aims to develop a pneumatic musculoskeletal biped robot, and its controller, to realize human-like walking. METHODS: According to the simplified musculoskeletal structure of human lower limbs, each leg of the biped robot is driven by nine muscles, including three pairs of monoarticular muscles which are arranged in the flexor-extensor form, as well as three biarticular muscles which span two joints. To lower cost, high-speed on/off solenoid valves rather than proportional valves are used to control the muscles. The joint trajectory tracking controller based on PID control method is designed to achieve the desired motion. Considering the complex characteristics of pneumatic artificial muscles, the control model is obtained through parameter identification experiments. RESULTS: Preliminary experimental results demonstrate that the biped robot is able to walk with this control strategy. CONCLUSION: The proposed musculoskeletal structure and control strategy are effective for the biped robot to achieve human-like walking.

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Motion Generation and Control for the Pneumatic Biped "Lucy"

Cited by 15 publications

References 10 publications

Treadmill walking of the pneumatic biped Lucy: Walking at different speeds and step-lengths

Treadmill walking of the pneumatic biped Lucy: Walking at different speeds and step-lengths

Novel Robotic Applications using Adaptable Compliant Actuation. An Implementation Towards Reduction of Energy Consumption for Legged Robots

Design and control of a pneumatic musculoskeletal biped robot

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