Control Design and Validation for Floating Piston Electro-Pneumatic Gearbox Actuator

Abstract

The paper presents the modeling and control design of a floating piston electro-pneumatic gearbox actuator and, moreover, the industrial validation of the controller system. As part of a heavy-duty vehicle, it needs to meet strict and contradictory requirements and units applying the system with different supply pressures in order to operate under various environmental conditions. Because of the high control frequency domain of the real system, post-modern control methods with high computational demands could not be used as they do not meet real-time requirements on automotive level. During the modeling phase, the essential simplifications are shown with the awareness of the trade-off between calculation speed and numerical accuracy to generate a multi-state piecewise-linear system. Two LTI control methods are introduced, i.e., a PD and an Linear-Quadratic Regulators (LQR) solution, in which the continuous control signals are transformed into discrete voltage solenoid commands for the valves. The validation of both the model and the control system are performed on a real physical implementation. The results show that both modeling and control design are suitable for the control tasks using floating piston cylinders and, moreover, these methods can be extended to electro-pneumatic cylinders with different layouts.

LPV-Based Controller Design of a Floating Piston Pneumatic Actuator

“…The controller can reach the requested gears with the discretization threshold tuned in simulation, but to meet the qualitative requirements, these thresholds are refined. The gear changes are shown in Figures 10-13 and the controller's performance is summarized in Table 3, where it is also compared with a gain-scheduled PD and an LQR controller presented in [43], which have been also on the same setup. The gear positions are the same, but initially, the position sensor's output was transformed to the lower end of the shift finger, hence the strokes on the diagrams differ between the two papers.…”

Reinforcement Learning Based Control Design for a Floating Piston Pneumatic Gearbox Actuator

“…In [53] the development and testing of a gain-scheduled PID controller and an LQR controller are presented. As the developed controllers were tested on the same system, their results can be used as a benchmark to justify or contradict the PG algorithm choice.…”

“…However, for exact comparison, the measurement results have been re-evaluated. In [53] four different test cases have been analyzed and the exact positions of the High and Low gears scatter around a nominal value, hence the shift time was calculated between the new request's emergence and reaching 90% of the reference position. This way, the performance of the different gear changes was unified.…”