COMBINE SPEED CONTROL

摘要

COMBINE SPEED CONTROL A ground speed control for an agricultural combine driven by a turbocharged engine through a variable transmission continuously monitors a plurality of speed and load parameters of the combine and engine, identifies the controlling parameter representing the limiting capacity in the harvesting process as field conditions change, and varies combine ground speed in response to such controlling parameter to maximize the harvest cutting rate. Sensors monitor ground speed, boost pressure and engine speed parameters and convert them to electrical signals which are compared to boost pressure and ground speed setpoint signals selected by the operator and to a fixed engine speed setpoint signal to derive error signals for such parameters. Voltage level sensitive OR-means and AND means establish deadbands for the error signals having upper and lower limits on opposite sides of the corresponding setpoint signals. The OR-means generates a speed decrease signal to decrease the transmission drive ratio and slow down the combine when any positive error signal is beyond its upper deadband limit. The AND-means generates a speed increase signal to increase the transmission drive ratio when both boost pressure and ground speed negative error signals are beyond their lower deadband limits. The speed increase and speed decrease signals are modulated by a rate of response signal which is a function of the magnitude of the parameter error signals so that the control both identifies and responds to the controlling parameter which has the greatest error and also responds at a rate which is a function of the magnitude of such error.