This document discusses using PI and PID controllers to control shaking in a bus suspension system. It first describes modeling a quarter-model of the bus suspension as a mass-spring-damper system. The open-loop response shows oscillations and long settling time. PI and PID controllers are then designed and applied in closed-loop control simulations in MATLAB to improve the response by reducing oscillations and shortening settling time. The PI controller uses proportional and integral terms, while the PID adds a derivative term. Both controllers are evaluated and compared based on time and frequency response characteristics.