This paper describes an improvement of pneumatic motor response for autonomous steering of conventional six-wheel dump trucks. Pneumatic motors are robust against overload, so it is considered suitable for the steering actuator of six-wheel dump trucks from the hardware point. However, a disadvantage of the pneumatic motor is the low performance of path tracking of the vehicle because of phase delay and dead time of the motor. Therefore, to improve the problem, in this research, the following four points were implemented: (1) modeling of the plant, (2) identification of model parameters, (3) designing feedforward controller with the inverse model of the plant, (4) evaluation of responsiveness by simulation. According to the above implementations, the delay time was reduced by about 70% for the application range of the feedforward compensation. Furthermore, by clarifying the pneumatic motor's applicable condition limits, the design guideline of the path planning for dump truck according to the vehicle speed is introduced.
