content: Hook your piezo sensors up on the contact points where the rider would normally give signals to real horse. Give the rider a mic.   Tell the rider to give the horse a command. Measure the numbers generated by the piezo sensors. Repeat x50 with the same rider.   Repeat Step 2 x50 different riders.   The numbers generated by the piezo sensors and the mics are your inputs to replace the joysticks of the radio-controller. (IF a$ >1 AND <100 THEN "go" etc.)   It's very simple, actually. Even a fine-art graduate could do it.