Applied Mechanics and Materials Vols. 284-287

Abstract: In this paper, we present the design and control of continuous passive motion (CPM) machine based on Constraint-Induced Movement Therapy (CIMT) for a patient who needs knee rehabilitation. First, the dynamic model of the CPM machine is derived by the principal of virtual work in dynamics. Then, an intelligent sliding-mode control (ISMC) system which involved recurrent Chebyshev neural network (RCNN) estimator to estimate the unknown external disturbance and uncertainty online is proposed to track the angular position and velocity of the CPM machine. Furthermore, we prove that the proposed ISMC system is asymptotically stable via Lyapunov theory. Finally, the experimental results are illustrated to demonstrate that the ISMC system can effectively reduce chattering phenomenon and precisely track reference trajectory of the CPM machine.

Abstract: This paper presents the interacting multiple model (IMM) particle filters with application to navigation sensor fusion. Performance evaluation for various single model nonlinear filters as well as nonlinear filters with IMM framework is carried out. A high gain (high bandwidth) filter is needed to response fast enough to the platform maneuvers while a low gain filter is necessary to reduce the estimation errors during the uniform motion periods. The IMM estimator obtains its estimate as a weighted sum of the individual estimates from a number of parallel filters matched to different motion modes of the platform. Based on a soft-switching framework, the IMM algorithm allows the possibility of using highly dynamic models just when required. The use of an IMM allows exploiting the benefits of high dynamic models in the problem of vehicle navigation. Some results presented in this paper confirm the improvements.

Abstract: Current coach mainly use the passive rubber mount system to isolate vibration, it’s hard to meet the engine broadband range isolation requirements. In order to reduce the coach engine vibration’s influence on the ride comfort and operational stability, it’s proposed that a magnetorheological fluid powertrain mount system. Set up the six degrees of freedom dynamic model and 1/4 engine single freedom vibration model. Design a fuzzy controller, which the input is dynamic exciting force and second order main frequency, the output is control current. Simulate the three types systems with the help of software of MATLAB/SIMULINK and Fuzzy control toolbox. The result shows that when fuzzy controller works, adjustable damping effect is obvious, it can attenuate vibration in large degree. The magnetorheological hydraulic mount with the fuzzy control ,compared with rubber mount and traditional hydraulic mount, has better isolation effect. Its damp can be controlled real-time, and it can be effective in isolation within the broadband.

Abstract: Maintaining gap between Electrode and workpiece in Electrical Discharge Machining (EDM) is very important since the capability of control system to keep the gap will improve the performance of this machine. Therefore to maintain the gap, a Proportional Integral Derivative (PID) controller is designed and applied to EDM servo actuator system. The objective of this work is to obtain a stable, robust and controlled system by tuning the PID controller using Differential Evolution (DE) algorithm. The controller for EDM die sinking is verified by simulation of the control system using MATLAB/Simulink program. Simulation results verify the capabilities and effectiveness of the DE algorithm to search the best configuration of PID parameters controller to control the electrode position.

Abstract: This paper describes an investigative hardware-in-the-loop simulation (HILS) effort through virtual instrumentation on longitudinal control of an unmanned aerial vehicle (UAV). The proportional-integral-differential (PID) controller and fuzzy logic controller (FLC) are designed for the pitch angle hold mode of autopilot; moreover, they are implemented by an embedded real-time control system as a prototype autopilot and tested by hardware-in-the-loop simulation. The hardware configuration of HILS is composed of a personal computer, an embedded real-time control system, several data acquisition devices, servo and sensor unit. The real-time control and data acquisition tasks in HILS is carried out by virtual instruments that is developed by graphical programming language LabVIEW. HILS provides a platform for researchers to correct and improve their design efficiently. The closed-loop performance between PID controller and FLC is evaluated in HILS. The results demonstrate that in the presence of unmodelled dynamics and nonlinear saturation the FLC has an excellent robust performance.

Abstract: This paper presents an automatic quality inspection system for the riveting process by using neural network (NN) techniques. Two types of neural models were used in studies. One is the conventional neural network and the other one is the quantum neural network which is expected to deal with the signals with fuzziness and uncertainty. The well-trained neural network could make an immediate diagnosis of the riveting quality based on the impact signals sensed. Thus, such NN inspection system can not only monitor the real time riveting process, but also give the assistance on the riveting quality verification. In order to demonstrate the superiority of neural network inspection system developed, the experimental data provided Chinese Air Force Institute of Technology was studied and simulated. The method of riveting quality index (RQI) was also performed as a comparison. From the simulation results shown, both of the proposed neural network inspection systems have the better verification accuracy than RQI method.

Abstract: As the production demand for laser drilled holes continues to grow, efficient and reliable process monitoring and control techniques are required in order to improve the manufacturing efficiency and reduce manufacturing cost for ensuring quality conformance. A robust, real-time monitoring system for breakthrough and the drilling depth detection in laser drilling is proposed. The system is based on based on coaxial visual sensing technology of the working surface using a CMOS camera, coupled with microcontroller control of the drilling laser operation. The camera is installed adjacent to the entry surface of the workpiece, and the spatial extend of the laser-induced plasma at the working site is monitored as the criterion for breakthrough detection. Therefore, on-line inspection system with low cost is developed to increase productivity. Experimental results show that the proposed system successfully detects when the laser beam has broken through a workpiece, and turns off the laser automatically by feedback control.

Abstract: In this paper, a remote filter design problem for a discrete-time singular plant under a networked control system is investigated. For a remote system, it is natural that transmitted signals have some delayed phenomenon and some data losing due to heavy loaded networks or under unreliable communication envelopment. In this case, a Bernoulli random distributed sequence is introduced to model the possible data losing, as well as the working but delayed transmitted signals are limited in some time interval. Applying a finite sum inequality approach, a set of delay dependent sufficient conditions for the admissibility analysis and the filter design problems are derived under an LMI framework. In order to verify and show the efficiency of the proposed method for such problem formulation, a numerical example is presented at the end of this paper.

Abstract: Parameter self-setting fuzzy PID control algorithm for control drying temperature is proposed to improve the problem about big fluctuations in temperature and high pellet broken rate of traditional control on Cold pressure ball drying system in this paper, and the controller create intelligence temperature control system through combine fuzzy control and PID control. We establish fuzzy controller, preparation of fuzzy look-up table in PLC and combined with PID control module to realize fuzzy PID control algorithm, through the computer simulation to analyze the fuzzy PID controller control effect.

Abstract: The quadrotor helicopter is designed to easily move in particular environments because it can take off and land in limited space and easily hover at a fixed location. For this reason, a robust adaptive sliding mode controller is developed to control of a quadrotor helicopter in the presence of external disturbances and parameter uncertainties. The quadrotor helicopter system is a typical underactuated system, which has fewer independent control actuators than degrees of freedom to be controlled. The main contribution here is to afford simulation and verification for the quadrotor helicopter flight controller under the assumption of unknown parameters. By utilizing the Lyapunov stability theorem, we can achieve asymptotic tracking of desired reference commands for the quadrotor helicopter, which is subject to both external disturbances and parametric uncertainties. From the simulation results, the controller was sufficient to achieve position and attitude control of the quadrotor helicopter system, which permits possible real time applications in the near future.