FUZZY LOGIC IMPROVED CONTROL DESIGN FOR ELECTRO-PNEUMATIC CLUTCH ACTUATION SYSTEM IN HEAVY DUTY VEHICLES

Abstract

This presentation focuses on enhancing the performance index of clutch actuation control process in an electro-pneumatic clutch system for heavy duty vehicles. The current weaknesses in performances of heavy-duty vehicles especially on hilly terrains which often lead to accidents can be traced to inadequacies in clutch actuation control. At present, conventional control techniques in clutch actuation uses on/off, servo mechanism and other non-intelligent methods of actuation control which calls for frequent but often neglected calibration of clutch actuators.  To eliminate calibration and its observed defects, an intelligent method of clutch actuation modelled in a fuzzy logic control is adopted. Conventional data obtained for errors, speed, torque and power from Mercedes Benz Actros Truck model MP 2 served as reference points. An intelligent agent-based actuation rule, modeled in a fuzzy logic fashion was developed. The Mandani model of fuzzy inference system in a MATLAB environment was adopted for the design The fuzzy logic control of forty-nine rules were developed for the input and three levels of outputs were obtained. Simulink models for both conventional and fuzzy logic controllers were also developed and simulated. Different percentages of improvements were recorded for piston error, engine torque, angular speed and power respectively in order to justify the research. An average percentage of improvements on conventional controllers compared to the fuzzy controllers stood at an error reduction in clutch travel from 0.720mm to 0.04171mm given an average reduction of 0.3029mm or a percentage decrease of 42%.  For the engine torque, an average increase from 0.18 NM to 0.21 NM or an increase of 0.03 NM, given a percentage increase of 15% was recorded. Similarly, increases were observed for power and angular speed.  Power increased from an average of 16.88 kilowatts to 18.25 kilowatts, resulting in 1.37kilowatts increase or 8 %, while angular speed was also increased from 1005 RPM to 1152 RPM, yielding an increase of 147RVPM or 15%. Arising from these results, it is conclusive that the deployment of fuzzy logic controller in clutch actuation control of an electro-pneumatic clutch actuation system will improve efficiency in heavy-duty vehicles. Indeed, it will make remarkable impact in the smooth operation of heavy-duty vehicles and hence limit the attendant calibration problems and associated poor performances in clutch actuation.

KEYWORDS:  Actuation, control, calibration, fuzzy logic, transmission