Nonlinear Model-Based Control of Pulse Width Modulated Pneumatic Servo Systems

2005 ◽  
Vol 128 (3) ◽  
pp. 663-669 ◽  
Author(s):  
Xiangrong Shen ◽  
Jianlong Zhang ◽  
Eric J. Barth ◽  
Michael Goldfarb
Keyword(s):  
Canonical Form ◽  
Nonlinear Model ◽  
Pulse Width ◽  
Sliding Mode ◽  
Control Input ◽  
Model Based Control ◽  
Pulse Width Modulated ◽  
Time Dynamics ◽  
Model Based ◽  
Actuation System

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 nonaffine in the input, into an equivalent system that is both continuous and affine in control input (i.e., transforms the system to nonlinear control canonical form). This approach is applied to a pneumatic actuator controlled by a pair of three-way solenoid actuated valves. The pneumatic actuation system is transformed into its averaged equivalent control canonical form, and a sliding mode controller is developed based on the resulting model. The controller is implemented on an experimental system, and the effectiveness of the proposed approach validated by experimental trajectory tracking.

Development of an Antagonistic SMA Actuator for Instar Rifle Stabilization System

Aerospace ◽  
2005 ◽  
Author(s):  
Brian Barnes ◽  
Diann Brei ◽  
Jonathan Luntz ◽  
Chris LaVigna
Keyword(s):  
Motion Control ◽  
Pulse Width ◽  
High Stress ◽  
Experimental Characterization ◽  
Pulse Width Modulated ◽  
Actuation System ◽  
Position Feedback ◽  
Sma Actuator ◽  
Feedback Control Strategy

Shape memory alloys are notoriously slow and suffer from creep and controllability issues [1,2]. This paper presents three methods to address these issues: a high-stress cyclic conditioning regime to reduce creep to operationally insignificant levels, an unconventional pulse-width-modulated duty cycle with heatsink to increase frequency to the ten hertz range, and simple position feedback control strategy for motion control. These methods are discussed within the context of a simple antagonistic leveraged SMA actuation system developed for an INertially STAbilized Rifle (INSTAR). An overview of design and basic parameter models for the L-Lever is provided along with benchtop experimental characterization of the quasistatic and dynamic behavior. The actuator was integrated into a one degree of freedom INSTAR platform to demonstrate the insitu methods via barrel control. The methods discussed in this paper led to a fast, low-creep, controllable actuator with outstanding authority resulting in precise barrel control with capabilities to greatly increase shooter accuracy.

Nonlinear Model Reduction for Automotive System Descriptions

2001 ◽  
Author(s):  
Zeyu Liu ◽  
John Wagner
Keyword(s):  
Dynamic System ◽  
Model Reduction ◽  
Nonlinear Model ◽  
Order System ◽  
Control Algorithms ◽  
Model Based Control ◽  
Reduction Strategy ◽  
Nonlinear Model Reduction ◽  
Model Based ◽  
Model Free

Abstract The mathematical modeling of dynamic systems is an important task in the design, analysis, and implementation of advanced automotive control systems. Although most vehicle control algorithms tend to use model-free calibration architectures, a need exists to migrate to model-based control algorithms which offer greater operating performance. However, in many instances, the analytical descriptions are too complex for real-time powertrain and chassis model-based control algorithms. Therefore, model reduction strategies may be applied to transform the original model into a simplified lower-order form while preserving the dynamic characteristics of the original high-order system. In this paper, an empirical gramian balanced nonlinear model reduction strategy is examined for the simplification process of dynamic system descriptions. The empirical gramians may be computed using either experimental or simulation data. These gramians are then balanced and unimportant system dynamics truncated. For comparison purposes, a Taylor Series linearization will also be introduced to linearize the original nonlinear system about an equilibrium operating point and then a balanced realization linear reduction strategy will be applied. To demonstrate the functionality of each model reduction strategy, two nonlinear dynamic system models are investigated and respective transient performances compared.

Design and Control of a Compact and Flexible Pneumatic Artificial Muscle Actuation System: Part Two—Robust Control

2011 ◽  
Author(s):  
Sai-Kit Wu ◽  
Garrett Waycaster ◽  
Tad Driver ◽  
Xiangrong Shen
Keyword(s):  
Robust Control ◽  
Nonlinear Model ◽  
Sliding Mode ◽  
Artificial Muscle ◽  
Control Approach ◽  
Actuation System ◽  
Highly Nonlinear ◽  
Pressure Dynamics ◽  
System Part ◽  
And Control

A robust control approach is presented in this part of the paper, which provides an effective servo control for the novel PAM actuation system presented in Part I. Control of PAM actuation systems is generally considered as a challenging topic, due primarily to the highly nonlinear nature of such system. With the introduction of new design features (variable-radius pulley and spring-return mechanism), the new PAM actuation system involves additional nonlinearities (e.g. the nonlinear relationship between the joint angle and the actuator length), which further increasing the control difficulty. To address this issue, a nonlinear model based approach is developed. The foundation of this approach is a dynamic model of the new actuation system, which covers the major nonlinear processes in the system, including the load dynamics, force generation from internal pressure, pressure dynamics, and mass flow regulation with servo valve. Based on this nonlinear model, a sliding mode control approach is developed, which provides a robust control of the joint motion in the presence of model uncertainties and disturbances. This control was implemented on an experimental setup, and the effectiveness of the controller demonstrated by sinusoidal tracking at different frequencies.

Nonlinear Model-Based Control of Nonminimum-Phase Processes

1998 ◽  
pp. 115-141 ◽  
Author(s):  
Costas Kravaris ◽  
Michael Niemiec ◽  
Ridvan Berber ◽  
Coleman B. Brosilow
Keyword(s):  
Nonlinear Model ◽  
Nonminimum Phase ◽  
Model Based Control ◽  
Model Based

Parameter Identification for Model-Based Control of Hydraulically Actuated Open-Chain Manipulators

2019 ◽  
Author(s):  
Lionel Hulttinen ◽  
Janne Koivumäki ◽  
Jouni Mattila
Keyword(s):  
Parameter Identification ◽  
Nonlinear Model ◽  
A Priori ◽  
Chamber Pressure ◽  
Hydraulic Actuator ◽  
Open Chain ◽  
Model Based Control ◽  
Model Based ◽  
Inertial Parameters ◽  
Manipulator Link

Abstract In this paper, a nonlinear model-based controller with parameter identification is designed for a rigid open-chain manipulator arm actuated by servovalve-controlled hydraulic cylinders. The arising problem in adopting model-based controllers is how to acquire accurate estimates of system parameters, with limited available information about either the hydraulic actuator parameters or manipulator link inertial parameters. The objective of this study is to identify both the rigid-body parameters of the links and the hydraulic actuator parameters from collected cylinder chamber pressure and joint angle data, while no a priori knowledge of these parameters is available. Same physical plant models are used for control design as well as for parameter identification. Experimental results show that the proposed nonlinear model-based control scheme results in acceptable Cartesian position tracking performance in free-space motion when using the identified parameters.

Nonlinear model based control of a piezoelectric actuated hydraulic valve

1999 ◽  
Vol 32 (2) ◽  
pp. 964-969
Author(s):  
Roland Kasper ◽  
Joachim Schröder ◽  
Andreas Wagner
Keyword(s):  
Nonlinear Model ◽  
Model Based Control ◽  
Model Based ◽  
Hydraulic Valve
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