US 8515637

Here is a concise summary of US patent 8515637:

US Patent 8515637: Machine control system and method

• Title: Machine control system and method
• Assignee: Caterpillar Inc.
• Inventors: Randall T. Anderson, Corwin E. Storer
• Filing Date: 2010-12-23
• Issue Date: 2013-08-20
• Abstract: A machine control system includes an input receiving portion configured to receive torque inputs related to a hydrostatic transmission. The input receiving portion also receives an operator request for actuating the hydrostatic transmission. The machine control system additionally includes a processor configured to determine a factor based at least in part on the torque inputs, for adjusting the operator request. The processor is further configured to determine a command for actuating the hydrostatic transmission based on the adjusted operator request, such that a torque load to be exerted on a power source by the hydrostatic transmission is within a desired range. The machine control system further includes an output sending portion configured to send the command to the hydrostatic transmission.

Plain-language Overview of Independent Claims:

• Claim 1 (Machine Control System): This claim describes a control system for a machine. It has a part that takes in information about the torque from a hydrostatic transmission and also an operator's command to use that transmission. A central processing unit (processor) in the system calculates an adjustment factor based on the torque information. This factor is then used to modify the operator's command. The processor then creates a final command for the hydrostatic transmission to ensure that the amount of force (torque load) the transmission puts on the machine's engine stays within an acceptable limit. Finally, another part of the system sends this adjusted command to the hydrostatic transmission.

• Claim 12 (Method for Controlling a Machine): This claim outlines a step-by-step process for controlling a machine equipped with an engine and a hydrostatic transmission. The method begins by gathering various inputs, specifically torque data related to the hydrostatic transmission and an operator's request to activate it. It then involves calculating an adjustment factor using this torque information to modify the operator's request. Following this, a command is determined for the hydrostatic transmission, ensuring that the torque load it applies to the engine remains within a safe operating range. This command is then sent to the hydrostatic transmission.

• Claim 17 (Machine): This claim defines a machine that includes an engine (power source) and a hydrostatic transmission (with at least one pump and one motor) driven by the engine. The machine incorporates a control system. This control system's input section is set up to receive two main types of torque information: a maximum allowable torque that the hydrostatic transmission can exert on the engine, and the actual torque it is currently exerting. It also receives an operator's command to actuate the transmission. A processor within this control system calculates an adjustment factor using both the allowed torque limit and the actual torque. This factor is used to modify the operator's command. The processor then generates a final command for the hydrostatic transmission, ensuring the torque load on the engine stays within a safe operating window. An output section then transmits this command to the hydrostatic transmission.

As of April 26, 2026, a search of the CAFC 2026 dockets did not reveal any active litigation specifically referencing patent US8515637. The patent is currently active and is set to expire on 2031-11-09.