Steering a Chaplygin Sleigh Using Periodic Impulses

Author(s):  
Phanindra Tallapragada ◽  
Vitaliy Fedonyuk

The control of the motion of nonholonomic systems is of practical importance from the perspective of robotics. In this paper, we consider the dynamics of a cartlike system that is both propelled forward by motion of an internal momentum wheel. This is a modification of the Chaplygin sleigh, a canonical nonholonomic system. For the system considered, the momentum wheel is the sole means of locomotive thrust as well the only control input. We first derive an analytical expression for the change in the heading angle of the sleigh as a function of its initial velocity and angular velocity. We use this solution to design an open-loop control strategy that changes the orientation of sleigh to any desired angle. The algorithm utilizes periodic impulsive torque inputs via the motion of the momentum wheel.

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen

Author(s):  
Imran Akhtar ◽  
Ali H. Nayfeh

Control of fluid-structure interaction is of practical importance from the perspective of wake modification and reduction of vortex-induced vibrations (VIVs). The aim of this study is to design a control to suppress vortex shedding. We perform a two-dimensional simulation of the flow past a circular cylinder using a parallel Computational Fluid Dynamics (CFD) solver. We record the velocity and pressure fields over a shedding cycle and compute the proper orthogonal decomposition (POD) modes of the divergence-free velocity and pressure, respectively. The Navier–Stokes equations are projected onto these POD modes to reduce the dynamical system to a set of ordinary-differential equations (ODEs). This dynamical system exhibits a limit cycle with negative linear damping and positive nonlinear damping. The reduced-order model is then modified by placing a pair of suction actuators and applying a control strategy using a control function method. We use the pressure POD mode distribution on the cylinder surface to optimally locate the actuators. We design a controller based on the linearized system and make it positively damped using pole-placement technique. The control-input settles to a constant value, suggesting constant suction through the actuators. We validate the results using CFD simulations in an open-loop setting and observe suppression of the hydrodynamic forces acting on the cylinder.


2008 ◽  
Author(s):  
Thomas Bifano ◽  
Jason Stewart ◽  
Alioune Diouf

2011 ◽  
Vol 418-420 ◽  
pp. 1865-1868
Author(s):  
Ming Jin Yang ◽  
Xi Wen Li ◽  
Zhi Gang Wang ◽  
Tie Lin Shi

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.


2002 ◽  
Vol 21 (10-11) ◽  
pp. 849-859 ◽  
Author(s):  
Kenneth A. Mcisaac ◽  
James P. Ostrowski

In this paper, we describe experimental work using an underwater, biomimetic, eel-like robot to verify a simplified dynamic model and open-loop control routines. We compare experimental results to previous analytically derived, but approximate expressions for proposed gaits for forward/backward swimming, circular swimming, sideways swimming and turning in place. We have developed a five-link, underwater eel-like robot, focusing on modularity, reliability and rapid prototyping, to verify our theoretical predictions. Results from open-loop experiments performed with this robot in an aquatic environment using an off-line vision system for position sensing show good agreement with theory.


AIAA Journal ◽  
1994 ◽  
Vol 32 (3) ◽  
pp. 555-563 ◽  
Author(s):  
Ellen K. Longmire ◽  
John K. Eaton

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