Learn More
This paper presents a control methodology that enables nonlinear model-based control of pulse width modulated (PWM) pneumatic servo actuators. An averaging approach is developed to describe the equivalent continuous-time dynamics of a PWM controlled nonlinear system, which renders the system, originally discontinuous and possibly non-affine in the input,(More)
This paper presents the design of a gas-actuated anthropomorphic arm prosthesis with 21 degrees of freedom and nine independent actuators. The prosthesis utilizes the monopropellant hydrogen peroxide as a gas generator to power nine pneumatic type actuators. Of the nine independent actuators, one provides direct- drive actuation of the elbow, three provide(More)
This paper presents a control methodology that enables nonlinear model based sliding mode control of PWM-controlled pneumatic servo actuators. An averaging approach is developed to describe the equivalent continuous-time dynamics of a PWM controlled nonlinear system, which renders the originally discontinuous system, possibly non-affine in the input, into(More)
This paper proposes a control approach that controls the stiffness and force of pneumatic actuator independently. This independent control of stiffness and force removes a primary cause of contact instability when utilizing stiffness or impedance based force control during interaction with stiff environments. Specifically, in typical stiffness or impedance(More)
The stable simulation of high-stiffness surfaces remains a challenge in impedance-type haptic simulations of mechanical environments. In this paper, the authors propose an approach to achieving a stable, high-stiffness surface in a haptic interface by leveraging the open-loop properties of pneumatic actuators. By using the open-loop component of the(More)
The presence of an intonational phrase boundary is often marked by three major acoustic cues: pause, final lengthening, and pitch reset. The present study investigates how these three acoustic cues are weighted in the perception of intonational phrase boundaries in two experiments. Sentences that contained two intonational phrases with a critical boundary(More)
This paper presents a new type of muscle-like actuator, namely double-acting (DA) sleeve muscle actuator, which is suitable for the actuation of biologically-inspired and biomedical robotic systems, especially those serving human-assistance purposes (prostheses, orthoses, etc.). Developed based on the traditional pneumatic muscle actuator, the new DA sleeve(More)