HYBRID FUZZY CONTROL FOR ELECTRO-HYDRAULIC ACTIVE DAMPING SUSPENSION

A new control scheme, the hybrid fuzzy control method, for active dampingsuspension system is presented. The scheme is the result of effective combination of the statisticaloptimal control method based on the statistical property of suspension system, with the bang-bangcontrol method based on the real-time characteristics of suspension system. Computer simulations areperformed to compare the effectiveness of hybrid fuzzy control scheme with that of optimal dampingcontrol, bang-bang control, and passive suspension. It takes the effects of time-variant factorsinto full account. The superiority of the proposed hybrid fuzzy control scheme for active dampingsuspension to the passive suspension is verified in the experiment study.

Adaptive Fuzzy Logic Controller for Harmonics Mitigation Using Particle Swarm Optimization

An excessive use of non-linear devices in industry results in current harmonics that degrades the power quality with an unfavorable effect on power system performance.In this research,a novel control techniquebased Hybrid-Active Power-Filter(HAPF)is implemented for reactive power compensation and harmonic current component for balanced load by improving the Power-Factor(PF)and Total–Hormonic Distortion(THD)and the performance of a system.This work proposed a soft-computing technique based on Particle Swarm-Optimization(PSO)and Adaptive Fuzzy technique to avoid the phase delays caused by conventional control methods.Moreover,the control algorithms are implemented for an instantaneous reactive and active current(Id-Iq)and power theory(Pq0)in SIMULINK.To prevent the degradation effect of disturbances on the system’s performance,PS0-PI is applied in the inner loop which generate a required dc link-voltage.Additionally,a comparative analysis of both techniques has been presented to evaluate and validate the performance under balanced load conditions.The presented result concludes that the Adaptive Fuzzy PI controller performs better due to the non-linearity and robustness of the system.Therefore,the gains taken from a tuning of the PSO based PI controller optimized with Fuzzy Logic Controller(FLC)are optimal that will detect reactive power and harmonics much faster and accurately.The proposed hybrid technique minimizes distortion by selecting appropriate switching pulses for VSI(Voltage Source Inverter),and thus the simulation has been taken in SIMULINK/MATLAB.The proposed technique gives better tracking performance and robustness for reactive power compensation and harmonics mitigation.As a result of the comparison,it can be concluded that the PSO-basedAdaptive Fuzzy PI system produces accurate results with the lower THD and a power factor closer to unity than other techniques.

NOVEL 6-DOF WEARABLE EXOSKELETON ARM WITH PNEUMATIC FORCE-FEEDBACK FOR BILATERAL TELEOPERATION

A particular emphasis is put on a novel wearable exoskeleton arm, ZJUESA, with 6 degrees of freedom, which is used for the robot teleoperation with the force-feedback in the unknown environment. In this external structure mechanism, the 3-revolution-prismatic-spherical （3RPS） parallel mechanism is devised from the concept of the human upper-limb anatomy and applied for the shoulder 3-DOF joint. Meanwhile, the orthogonal experiment design method is introduced for its optimal design. Aiming at enhancing the performance of teleoperation, the force feedback is employed by the pneumatic system on ZJUESA to produce the vivid feeling in addition to the soft control interface. Due to the compressibility and nonlinearity of the pneumatic force feedback system, a novel hybrid fuzzy controller for the precise force control is proposed and realized based on the Mega8 microcontroller units as the units of the distributed control system on ZJUESA. With the results of several experiments for master-slave control with force feedback, the feasibility of ZJUESA system and the effect of its hybrid fuzzy controller are verified.

Multi-Branch Cable Harness Layout Design Based on Genetic Algorithm with Probabilistic Roadmap Method

Current studies on cable harness layouts have mainly focused on cable harness route planning.However,the topological structure of a cable harness is also extremely complex,and the branch structure of the cable harness can affect the route of the cable harness layout.The topological structure design of the cable harness is a key to such a layout.In this paper,a novel multi-branch cable harness layout design method is presented,which unites the probabilistic roadmap method(PRM)and the genetic algorithm.First,the engineering constraints of the cable harness layout are presented.An obstacle-based PRM used to construct non-interference and near to the surface roadmap is then described.In addition,a new genetic algorithm is proposed,and the algorithm structure of which is redesigned.In addition,the operation probability formula related to fitness is proposed to promote the efficiency of the branch structure design of the cable harness.A prototype system of a cable harness layout design was developed based on the method described in this study,and the method is applied to two scenarios to verify that a quality cable harness layout can be efficiently obtained using the proposed method.In summary,the cable harness layout design method described in this study can be used to quickly design a reasonable topological structure of a cable harness and to search for the corresponding routes of such a harness.

Generation mechanism and control of high-frequency vibration for tracked vehicles

A crawler system provides much larger ground contact,leading to excellent terrain adaptability.Due to its structural characteristics,high‐frequency vibration proportional to the vehicle speed is generated during the driving process.This is a result of the polygon and rolling effects between the track and the wheels.A field test of a tracked vehicle is performed to monitor movement signals of the chassis and a rocker arm.Their corresponding power spectral density distributions confirm the correctness of the frequency‐calculation equation.Then,a novel elastic track tensioning device with a damper is designed as a cushion between the idler and the chassis.Depending on its geometry,the equivalent damping coefficient for a dynamic model is evaluated.Subsequently,the damping is altered in response to different operating conditions by a hybrid damping fuzzy semiactive control system.The controller accounts for both chassis and track vibration.Based on the transfer matrix method for multibody systems,a dynamical model of the track system is developed.Control performances are evaluated using two numerical simulations of obstacle crossing and off‐road driving operations.Results indicate that the proposed semiactive tensioner is substantially better than the conventional one.This paper provides a novel feasible scheme for vibration reduction of tracked vehicles.