Optimization of constant-speed control algorithm for high-speed EMUs

Constant-speed control is deemed one of the core control functions for high speed EMUs, with accuracy being crucial for ensuring smooth operation. Given the complex operational environments of trains, ensuring the accuracy of constant-speed control for high-speed EMUs remains a research challenge in the industry. This paper presents a piecewise centralized control method based on PID regulation, which features the piecewise setting of key parameters, such as proportional, calculus coefficients. As train speeds greatly different from the target speed, proportional regulation allows for the maximum output of traction/braking force to facilitate a quick adjustment to the target speed. As train speeds approaching the target speed, the proportional regulation gradually diminishes in the control, while speed fine-tuning is achieved through the integral and differential elements. Additionally, in order to prevent abrupt changes in traction/braking force and rapid switching between traction and braking, additional control functions are incorporated in the PID regulation algorithm, focusing on train impact rates and traction/braking switching. The actual implementation of the proposed method demonstrated a control precision 7 times higher than that of the original control method, underscoring its potential for wide applications in various vehicle models.