This paper discusses the (inverse) optimality and practical usage of passivitybased controls for distributed port-Hamiltonian systems. We first clarify that passivity-based controls, damping assignment and potential shaping can be derived from a linear quadratic type optimal control problem. Next, we describe the limitation of passivity-based boundary controls and propose a practical usage of t...

In this paper an approach for robot force/position control combined with an iterative learning control is proposed. Following high speed force trajectories in different repetitive robotic applications is a challenging field in robotics. Such applications require a desired contact force while following a position/orientation trajectory in the non-force controlled directions. For this a parallel ...

− Studies of arm movement have suggested that the control of stiffness may be important for maintaining stability during interactions with the environment. Here we have examined the voluntary control of stiffness in the human jaw. The goal was to determine whether changes in jaw stiffness might be used to maintain jaw position in the face potentially destabilizing mechanical loads. A series of ...

In this paper, we propose a control system that changes the compliance based on the walking speed to stabilize biped walking on rough terrain. The proposed system does not use the inclination of the terrain. Instead, the system changes walking modes depends on its walking speed. In the downhill terrain, when the walking speed is increased, the stiffness of the ankle in the support phase is cont...

Absfracf-The goal of this study is to develop a mechanical system which display elastic characteristic like stiffness on the surface of human body aiming at applying to palpation simulator. Pneumatic parallel manipulator is employed as a driving mechanism, consequently, it brings capability of minute force displaying property owing to the air compressibility. Compliance control system without u...

A mathematical formalism for designing running gaits in bipedal robots with compliance is introduced and subsequently validated experimentally on MABEL, a planar biped that contains springs in its drivetrain. The methods of virtual constraints and hybrid zero dynamics are used to design a time-invariant feedback controller that respects the natural compliance of the open-loop system. In additio...

Actuators that bend slice lips are commonly used in cross-directional (CD) control systems for paper making and plastic film extrusion. A dynamic model of these actuators is developed which is used to investigate their spatial modes and dynamic responses. The model shows that both the shape and the amplitude of the spatial response depend upon the stiffness of the slice lip. The design of most ...

We tested an innovative method to estimate joint stiffness and damping during multijoint unfettered arm movements. The technique employs impulsive perturbations and a time-frequency analysis to estimate the arm's mechanical properties along a reaching trajectory. Each single impulsive perturbation provides a continuous estimation on a single-reach basis, making our method ideal to investigate m...

Motor dynamics in antagonistic variable stiffness actuator (AVSA) is generally disregarded control system design. This ignorance can lead to an inaccurate model, affecting the performance of closed-loop system. The motor be modeled as input-delay model. In this paper, input time-delay for AVSA first time. a nonlinear function states; thus, tracking challenging task. Specifically, many existing ...