Abstract: A method and apparatus for preventing underdigging of a work machine, which may occur if the implement digs under or too close to the work machine, is disclosed. An underdigging boundary or a space of allowable implement movement is established relative to the work machine. The position of the implement is sensed, and the movement of the implement is controllably prevented from underdigging the work machine.

Abstract: A control system for lubricating a work machine is provided. The control system includes a lubricant distribution system, a charging system adapted to drive the lubricant distribution system, a sensor for determining the operating state of the charging system, and a device for calculating a time interval being dependent upon a previous lubricating event. The control also includes a device for producing a lubrication signal in response to the time interval reaching a predetermined interval constant.

Abstract: A cold fluid protection circuit is provided for controlling the rate of fluid flow in a hydraulic system in response to the temperature of the oil in a reservoir. The subject invention includes a temperature sensor operative to sense the temperature of the fluid in the reservoir and deliver an electrical signal representative thereof to a controller. The controller processes the sensed temperature with respect to the rate of flow in the hydraulic system that is returning to the reservoir from an actuator through a fluid conditioning mechanism and proportionally reduces the rate of flow therethrough by controllably reducing the displacement of a directional valve mechanism in response to the sensed temperature.