Method and apparatus for sensing pedal motion and actuating pedals in player pianos

A piano pedal sensor apparatus, comprising:

• (a) a plurality of optical reflectors, each said reflector mounted on a moving portion of a piano pedal assembly;
• (b) a plurality of optical emitters and corresponding optical sensors, said optical emitters and optical sensors mounted on a stationary portion of said piano pedal assembly, each said optical emitter positioned to emit light towards a corresponding said optical reflector, each said optical sensor positioned to sense light reflected by said corresponding said optical reflector, each said optical sensor producing an output voltage responsive to intensity of said sensed light;
• (c) an analog to digital converter, said analog to digital converter operatively coupled to each said optical sensor;
• and
• (d) a control computer, said control computer operatively coupled to said analog to digital converter, said control computer including a stored look-up table of pedal position data, said control computer including program means for periodically sampling digitized optical sensor output from said analog to digital converter and for determining pedal position values from said pedal position data in said stored look-up table which correspond to said sampled digitized optical sensor output.

A method for detecting pedal expression in an acoustic piano performance, comprising the steps of:

• (a) providing a plurality of optical reflectors, each said reflector mounted on a piano pedal assembly;
• (b) providing a plurality of optical emitters and corresponding optical sensors, said optical emitters and optical sensors mounted on said piano pedal assembly, each said optical emitter positioned to emit light towards a corresponding said optical reflector, each said optical sensor positioned to sense light reflected by said corresponding said optical reflector, said optical reflectors separated from said corresponding said optical emitters and said optical sensors by a distance which varies in response to movement of piano pedals;
• (c) sensing, by said optical sensors, light from said optical emitters which is reflected by said optical reflectors;
• and
• (d) determining pedal position values according to said light sensed by said optical sensors.