What does PID mean and some of it's uses in a motorsports ECU's?

Posted by Tony eigenseher on

PID stands for Proportional-Integral-Derivative, which refers to a type of control algorithm used in various applications, including industrial automation, robotics, and engineering systems. The PID controller uses feedback from a process or system and calculates the appropriate output based on three parameters - proportional, integral, and derivative.

The proportional parameter controls the magnitude of the output in proportion to the error between the process value and the desired setpoint. The integral parameter calculates the accumulated error over time and adds a corrective output to reduce the steady-state error. The derivative parameter measures the rate of change of the error and adds a dampening effect to the output to prevent overshoot or oscillations.

The importance of PID control lies in its ability to maintain accurate and stable control of a system or process. By adjusting the output in real-time based on the feedback from the system, a PID controller can maintain precise and consistent control, even in the presence of external disturbances or changes in the system.

PID's are used in many functions of an Engine's operation; DBW(Drive by wire throttle body, VVT(variable valve timing), Idle control etc...

One example would be for Electronic Boost Control (EBC) using closed loop boost control: Boost Solenoid

Boost control is an essential part of any high-performance turbocharged or supercharged engine. Boost pressure is a crucial parameter that determines the power and torque output of an engine. A boost controller manages the turbocharger's wastegate or bypass valve to regulate the boost pressure and achieve the desired level of performance. example picture below;

Traditionally, boost control was achieved using a simple mechanical or pneumatic system, which provided limited control and tuning options. However, modern engine management systems use advanced electronic boost control systems, which can precisely control the boost pressure using a PID controller.

A PID controller can adjust the wastegate or bypass valve position to maintain the desired boost pressure by continuously monitoring the pressure and adjusting the output based on the three PID parameters - proportional, integral, and derivative.

The proportional parameter controls the response to the error between the actual and target boost pressure. A higher proportional gain results in a faster response to changes in the boost pressure but may also lead to overshoot or oscillations. The integral parameter calculates the accumulated error over time and adds a corrective output to reduce the steady-state error. The derivative parameter measures the rate of change of the error and adds a dampening effect to the output to prevent overshoot or oscillations.

The PID controller's output is used to adjust the wastegate or bypass valve's position to maintain the target boost pressure. The engine management system can tune the PID parameters to achieve the desired boost response and stability for different driving conditions, such as idle, cruising, or full-throttle acceleration.

The advantages of using a PID controller for boost control include precise and stable control of the boost pressure, fast response to changes in engine load or ambient conditions, and flexibility in tuning for different engine configurations and driving conditions.

In conclusion, boost control with a PID controller is a powerful and effective way to achieve optimal performance from a turbocharged engine. The ability to precisely control the boost pressure and tune the response and stability to various driving conditions is essential for maximizing power and efficiency while ensuring reliable and safe operation.

Overall, PID controllers are an essential tool for maintaining precise and stable control of complex systems, and their use is critical in a wide range of industries and motorsport applications.