Spray Paint Monitoring and Control Using Doppler Radar Techniques

Author:  J. Doughty, G. Brand, J. Josefowicz
Source:  US Patent 5,315,306
Doc ID:  1994024
Year of Publication:  1994
Abstract:  
Systems and methods that use a CW Doppler radar to monitor paint particle velocities as they are sprayed from a paint gun to optimize the application of strayed paint onto the object, and provide a closed loop spray painting system and paint spraying method that controls the application of paint in real time using data generated by the radar. The Doppler radar and a signal analyzer are used to analyze the Doppler return signals and display data indicative of the volocity of the paint particles. The data may be used by an operator to manually adjust the paint spray system. In addtition, the spectrum analyzer may be used to generate and couple control signals to the paint spray system to provide for closed loop feedback control of thereof. One method comprises the following steps. Spraying paing particles toward an object that is to be painted using a paint spray gun. Radiating Doppler radar signals at the paint particles that are moving toward the object. Receiving back scattered Doppler shifted radar returns from the moving paint particles. Processing the received back scattered Doppler shifted radar returns to produce data indicative of the volocity of the paint particles. Displaying the data indicative of the velocity of the paint particles. This method unobstructively and remotely measures paint particle velocity and velocity distribution. By additionally generating control signals in response to the data, the paint spray system is controlled.