Identification in a Laboratory Tunnel to Control Fluid Velocity

摘要

In this paper the method of fluid velocity control in the laboratory water tunnel is presented. The water tunnel is designed for measurements of undulating propulsion system for biomimetic underwater vehicle (BUV). The undulating propulsion system consists of the fin, servomotor, power supply and control unit. Due to the fluid structure interaction between the fin and water, special requirements arising from fluid mechanics theory must be met. It means that experimental measurements are reliable only if the generated propulsion force is measured for a dynamic state. The aim of the fluid velocity control system is to compensate the undulating propulsion force by additional, external water pump. For constant fluid velocity an average value of the force generated by the undulating propulsion system should maintain at zero. For this reason, the external water pump is going to be controlled as a function of average value of the force generated by the undulating propulsion system. The fluid velocity as a function of the control signal for external pump should be identified due to the unknown characteristic caused mainly by resistance losses in the water tunnel and the nonlinear characteristic of the water pump. This paper presents an identification problem to design the control system for maintaining the desired water velocity in the laboratory test stand.