In-vehicle dynometer

A method for determining the torque of an engine of a work machine, comprising:

• providing a controller having a processor and a memory unit, an input, at least one parasitic device, and a hydraulic system having a pump and a pressure sensor;
• storing, in the memory unit of the controller, a parasitic load table that identifies a parasitic torque load based on an engine speed;
• detecting, with the controller, a signal from the input to initiate a torque measurement procedure stored in the memory unit;
• executing the torque measurement procedure, with the controller, by sending a signal to the engine to run in a wide open throttle condition;
• setting, with the controller, the displacement of the hydraulic system between a minimum and a maximum displacement and storing a displacement value in the memory unit;
• detecting a fluid pressure of the hydraulic system with the pressure sensor and communicating the detected fluid pressure to the controller;
• operating the engine at the wide open throttle condition and communicating an operating engine speed to the controller;
• identifying, with the controller, a parasitic torque from the parasitic load table as a function of the operating engine speed;
• calculating, with the controller, a hydraulic torque based on the set displacement value and the detected fluid pressure;
• determining, with the controller, a total engine torque as a function of the parasitic torque and the hydraulic torque;
• and
• using the controller to disengage the at least one parasitic device from the engine during the executing the torque measurement procedure step.

A method for determining the torque of an engine of a work machine, comprising:

• providing a controller integrated into a control system of the work machine, the controller having a processor and a memory unit, an input, at least one parasitic device, a pressure sensor, and a hydraulic system having a pump;
• storing, in the memory unit of the controller, a parasitic load look-up table with parasitic load values as a function of engine speed and a pump displacement look-up table with pump displacement values as a function of engine speed;
• detecting a signal from the input to execute a torque measurement procedure;
• executing the torque measurement procedure, with the controller, by operating the engine at a wide open throttle condition, wherein the engine speed in the wide open throttle condition overrides a user speed command requested by a user;
• setting, with the controller, the hydraulic system at a fluid pressure between a minimum and a maximum pressure;
• measuring a fluid pressure of the hydraulic system with the pressure sensor and communicating a measured fluid pressure to the controller;
• communicating an operating engine speed to the controller;
• identifying, with the controller via the pump displacement look-up table and the parasitic load look-up table, the parasitic load values and the displacement value based on the operating engine speed;
• calculating, with the controller, a hydraulic torque based on the displacement value and the measured fluid pressure;
• and
• determining, with the controller, a total engine torque as a function of the parasitic load values and the hydraulic torque;
• and
• enabling the controller to respond to the user speed command once the total engine torque is determined.