Fractional Integrated Dual Electromagnetic Retarder Controller for Tuning Internal Combustion Engines

Abstract

The laboratory bench was developed for tuning the fuel system of an internal combustion engine on the basis of two electromagnetic retarders connected to the drive wheels of the car, and a microprocessor-based torque control system for each brake. The purpose of the research is the synthesis of controllers, testing, the choice of the structural scheme, parameters of the control and data processing system in the bench for the precision tuning of internal combustion engines. Based on a preliminary analysis of the system, taking into account the mechanical connection of the wheels through the main gear and the car differential, the nonlinear dependence of the electromagnetic torque on the current and retarder speed, and subsequent experimental results, two types of control object models are obtained – a third-order aperiodic transfer function and a fractional aperiodic transfer function of order 1.6. This allowed us to synthesize a family of controllers that ensure the operation of the bench in several modes – synchronization of wheel rotation speeds during engine acceleration; stabilization of reference speed when the engine torque changes; the mode of measuring the maximum power and torque of the internal combustion engine at a linearly increasing speed. The system with the PID-controller configured in MATLAB in the “Tune” package has the best performance, but the smallest overshoot and the best dynamic accuracy were ensured by the PIDIγ Iμ fractional-integral controller, with which the system is characterized by a fractional order of astaticism 1.6. Such a controller for each electromagnetic retarder has become the basis of the microprocessor-based control, data acquisition, processing, graphical display system, and will also be used to develop a similar bench for tuning the four-wheel-drive vehicle.