Track trencher propulsion system with component feedback

A control system for controlling propulsion of a vehicle, the vehicle including an excavation attachment powered by an attachment hydrostatic drive, the attachment hydrostatic drive including a hydraulic pump and a hydraulic motor, the control system comprising:

• a controller that generates a vehicle propulsion drive signal for controlling propulsion of the vehicle, the controller using a hydraulic pressure of the attachment hydrostatic drive as a variable for modifying the propulsion drive signal;
• wherein the control system defines an attachment pressure band, and wherein when the hydraulic pressure of the attachment hydrostatic drive is within the pressure band a magnitude of the vehicle propulsion drive signal decreases in response to an increase in the hydraulic pressure of the attachment hydrostatic drive and increases in response to a decrease in the hydraulic pressure of the attachment hydrostatic drive;
• wherein the attachment hydrostatic drive is powered by an engine having an engine speed, wherein the controller uses the engine speed as another variable for modifying the vehicle propulsion drive signal, wherein the control system defines an engine speed band, and wherein when the engine speed is within the engine speed band the magnitude of the vehicle propulsion drive signal increases in response to an increase in the engine speed and decreases in response to a decrease in the engine speed;
• wherein the vehicle propulsion drive signal controls a hydrostatic propulsion drive that drives a vehicle propulsion structure, wherein the hydrostatic propulsion drive includes a propulsion drive speed and a propulsion drive pressure, and wherein the controller uses a plurality of operator selectable feedback algorithms to determine a characteristic response of the vehicle propulsion drive signal, the plurality of operator selectable feedback algorithms including:
• a first algorithm that uses factors based on the hydraulic pressure of the attachment hydrostatic drive, the speed of the engine and a difference between a measured propulsion drive speed and a calculated propulsion drive speed to scale the vehicle propulsion drive signal;
• a second algorithm that uses factors based on the hydraulic pressure of the attachment hydrostatic drive, the speed of the engine and a difference between a measured propulsion drive pressure and a calculated propulsion drive pressure to scale the vehicle propulsion drive signal;
• and
• a third algorithm that uses the hydraulic pressure of the attachment hydrostatic drive and the engine speed as factors to scale the vehicle propulsion drive signal and does not use the difference between the measured propulsion drive speed and the calculated propulsion drive speed or the difference between the measured propulsion drive pressure and the calculated propulsion drive pressure as factors to scale the vehicle propulsion drive signal.

A control system for controlling propulsion of a vehicle over a ground surface by a vehicle propulsion system, the vehicle having a vehicle chassis, the vehicle also including an engine that powers the vehicle propulsion system and also powers an excavation system, the excavation system including an excavation attachment mounted to the vehicle chassis, the excavation attachment having an active portion that is moved in a cutting motion by an attachment drive during excavation, the active portion including a plurality of cutting teeth, the excavation system also including an actuator for raising and lowering the excavation attachment relative to the vehicle chassis, the control system comprising:

• an electronic controller that generates a vehicle propulsion drive signal for controlling propulsion of the vehicle by the vehicle propulsion system, the vehicle propulsion drive signal being an electronic signal, wherein during excavation operations:
• a) the vehicle propulsion system causes the active portion of the excavation attachment to be driven into unexcavated ground while the attachment drive moves the active portion of the excavation attachment in a cutting motion adapted for breaking-up the ground;
• and b) the electronic controller uses a parameter of the excavation system indicative of load on the excavation attachment during excavation operations as a feedback variable for automatically modifying the vehicle propulsion drive signal.