In this paper, robust force/motion control strategies are presented for mobile manipulators under both holonomic and nonholonomic constraints in the presence of uncertainties and disturbances. The proposed control strategies guarantee that the system motion converges to the desired manifold with prescribed performance, and constraint force control is developed using the passivity of hybrid join...

Force controlled series elastic actuators (SEA’s) are widely used components of novel physical human-robot interaction applications such as assistive and rehabilitation robotics. These systems are characterized by the presence of the “human in the loop” so that control response and stability depend on uncertain human dynamics. A common approach to guarantee stability is to use a passivity-based...

In this paper, dynamic multilayer neural networks are used for nonlinear system on-line identification. Passivity approach is applied to access several stability properties of the neuro identifier. The conditions for passivity, stability, asymptotic stability and inputto-state stability are established. We conclude that the commonly-used backpropagation algorithm with a modification term which ...

A new image-based control strategy for visual servoing of a class of under-actuated rigid body systems is presented. The proposed control design applies to “eye-in-hand” systems where the camera is fixed to a rigid body with actuated dynamics. The control design is motivated by a theoretical analysis of the dynamic equations of motion of a rigid body and exploits passivity-like properties of th...

In this paper, dynamic neural networks are used for engine model at idle speed on-line identification. Passivity approach is applied to access several stability properties of the neuro identifier. The conditions for passivity, stability, asymptotic stability and input-to-state stability are established. We conclude that the commonly-used backpropagation algorithm with a modification term which ...

This paper presents a framework for control design of general nonlinear switched systems using passivity and two passivity indexes. Background material will be presented on traditional passivity for continuously varying systems, the concept of a passivity index, and passivity theory for switched systems. The passivity index concept will then be generalized to apply to switched systems to measur...

We present a novel control design procedure for the passivity-based stabilization of closed sets which leverages recent theoretical advances. The procedure involves using part of the control freedom in order to enforce a detectability property, while the remaining part is used for passivity-based stabilization. The procedure is illustrated in four case studies of path following coordination for...

Human operated, hydraulic actuated machines are widely used in many high-power applications. Improving productivity, safety and task quality (eg. haptic feedback in a teleoperated scenario) has been the focus of past research. For robotic systems that interact with the physical environments, passivity is a useful property for ensuring safety and interaction stability. While passivity is a well ...

The relationship between perceived loss of control and passivity in social activities in a non-handicapped institutionalized elderly population was assessed. Perceived loss of control was assessed from three different types of expectancies: low action-outcome expectancies, high situation-outcome expectancies, and low efficacy expectancies. Passivity scores were reported by the staff. The effect...

This paper describes a general passivity-based framework for the control of flexible joint robots. Recent results on torque, position, as well as impedance control of flexible joint robots are summarized, and the relations between the individual contributions are highlighted. It is shown that an inner torque feedback loop can be incorporated into a passivity-based analysis by interpreting torqu...