scholarly journals One Nonlinear PID Control to Improve the Control Performance of a Manipulator Actuated by a Pneumatic Muscle Actuator

2014 ◽  
Vol 6 ◽  
pp. 172782 ◽  
Author(s):  
Jun Zhong ◽  
Jizhuang Fan ◽  
Yanhe Zhu ◽  
Jie Zhao ◽  
Wenjie Zhai
Keyword(s):  
Hysteretic Behavior ◽  
Linear Component ◽  
Pneumatic Muscle ◽  
Pid Algorithm ◽  
Nonlinear Properties ◽  
Proposed Model ◽  
Highly Nonlinear ◽  
Position Controller ◽  
Nonlinear Pid Control ◽  
Pneumatic Muscle Actuator

Braided pneumatic muscle actuator shows highly nonlinear properties between displacements and forces, which are caused by nonlinearity of pneumatic system and nonlinearity of its geometric construction. In this paper, a new model based on Bouc-Wen differential equation is proposed to describe the hysteretic behavior caused by its structure. The hysteretic loop between contractile force and displacement is dissolved into linear component and hysteretic component. Relationship between pressure within muscle actuator and parameters of the proposed model is discussed. A single degree of freedom manipulator actuated by PMA is designed. On the basis of the proposed model, a novel cascade position controller is designed. Single neuron adaptive PID algorithm is adopted to cope with the nonlinearity and model uncertainties of the manipulator. The outer loop of the controller is to handle position tracking problem and the inner loop is to control pressure. The controller is applied to the manipulator and experiments are conducted. Results demonstrate the effectiveness of the proposed controller.

scholarly journals Position Control of a Pneumatic Muscle Actuator Using RBF Neural Network Tuned PID Controller

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Jie Zhao ◽  
Jun Zhong ◽  
Jizhuang Fan
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Phenomenological Model ◽  
Pid Controller ◽  
Position Control ◽  
Rbf Neural Network ◽  
Pneumatic Muscle ◽  
Highly Nonlinear ◽  
Experimental Apparatus ◽  
Pneumatic Muscle Actuator

Pneumatic Muscle Actuator (PMA) has a broad application prospect in soft robotics. However, PMA has highly nonlinear and hysteretic properties among force, displacement, and pressure, which lead to difficulty in accurate position control. A phenomenological model is developed to portray the hysteretic behavior of PMA. This phenomenological model consists of linear component and hysteretic component force. The latter component is described by Duhem model. An experimental apparatus is built up and sets of experimental data are acquired. Based on the experimental data, parameters of the model are identified. Validation of the model is performed. Then a novel cascade position PID controller is devised for a 1-DOF manipulator actuated by PMA. The outer loop of the controller is to cope with position control whilst the inner loop deals with pressure dynamics within PMA. To enhance the adaptability of the PID algorithm to the high nonlinearities of the manipulator, PID parameters are tuned online using RBF Neural Network. Experiments are performed and comparison between position response of RBF Neural Network based PID controller and that of classic PID controller demonstrates the effectiveness of the novel adaptive controller on the manipulator.

Position Control of PWM-Actuated Pneumatic Muscle Actuator System

2011 ◽  
Author(s):  
Ville Jouppila ◽  
Asko Ellman
Keyword(s):  
Position Control ◽  
System Model ◽  
Modeling Error ◽  
Stick Slip ◽  
Pneumatic Muscle ◽  
Positioning Systems ◽  
Highly Nonlinear ◽  
Pneumatic Muscle Actuator ◽  
Non Linear System ◽  
Real Challenge

Pneumatic servo positioning systems have been in use for long time and subject to wide spectrum of studies due to their numerous advantages: inexpensive, clean, safe and high ratio of power to weight. However, the compressibility of air and the inherent non-linearity of these systems continue to make achieving accurate position control a real challenge. Conventional pneumatic servo systems are based on cylinder actuators that are difficult to control precisely due to the aforementioned nonlinearities as well as the nonlinear behavior of the air flow through the valve, the friction between the cylinder and the piston, and the stick slip effect at the low velocity of the system. In this paper, a position servo control system using a pneumatic muscle actuator is studied. Pneumatic muscle actuator is a novel type of actuator which has even higher force to weight ratio than the cylinder. In addition, muscle actuator introduces a stick slip free operation giving an interesting option for positioning systems. However, significant hysteresis and position dependant force result in a highly nonlinear system, a real challenge for good control performance. In this paper, pneumatic muscle actuator is controlled by a low-cost on/off valve with PWM-strategy instead of costly servo or proportional valve. The main processes of the system, including flow dynamics, pressure dynamics, force dynamics and load dynamics are derived to provide a full nonlinear model that captures all the major nonlinearities of the system. This model is used for analyzing and tuning the controller performances by simulations before implementing in the real system. In addition, a recently introduced method of using bipolynomial functions to model the valve flow rate is utilized to provide a continuous and invertible description of flow for controller designs. A proportional plus velocity plus acceleration controller with feed-forward component (PVA+FF) is designed based on the linearized system model. For a comparison, a sliding mode controller (SMC) based on linear as well as non-linear system model are designed. The performance of the designed controllers is studied by simulations. The stability and performance analysis includes the effects of friction modeling error and valve modeling error. The robustness of the controllers is tested by varying the payload mass of the system.

Proposed model of all optical reversible and irreversible modules on a single photonic circuit

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ritvik Shukla ◽  
Salini Bose ◽  
Shubham Shukla ◽  
Kamal Kishor Upadhyay ◽  
Nikhlesh Kumar Mishra ◽  
...  
Keyword(s):  
Extinction Ratio ◽  
Data Communication ◽  
Electrical Signal ◽  
Optical Channel ◽  
Nonlinear Properties ◽  
Proposed Model ◽  
Photonic Circuit ◽  
The Cost ◽  
Audio Video ◽  
Logic Unit

AbstractIn the current era of data communication everyone deals with the huge amount of data in form of text, audio, video and different other formats in which everyone want a secure and higher bandwidth channel to transmit and receive so, only the optical channel provides the solution of above said problem. The only difficulty with the existing model that the data from electrical domain first converted in form of light (optical domain) at the transmission end while after receiving the data at the receiver end it will be further converted in form of electrical signal for extracting the message. This type of conversion from one domain to other gives the energy loss. In the current research article, we proposed a model of optical processor which transmit and receive the data without conversion which provides an energy efficient optical technology. By adding reversibility, heat bender can be further reduced. In this manuscript, an arithmetical logic unit has been created, a photonic reversible complete subtractor and an irregular logic portal. SOA-MZI structure is the basic component of the architecture. The method is mainly carried out by the semiconductor Amplifier, using nonlinear properties such as cross-gain modulation and cross-phase modulation. The efficiency deciding factor for the whole system is 21.23 and 53.27 dB in the average extinction ratio. The cost of the arithmetic logic unit optically constructed is 9.

Sign in / Sign up

Export Citation Format

Share Document