# US 2019/0172274 A1 · Method and apparatus to monitor an on-vehicle fluidic subsystem > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0172274 A1 - Document ID: US20190172274A1 - Status: Published application - Kind: A1 - Application number: 15/830,262 - Filed: 2017-12-04 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Shiming Duan; Yao Hu; Christopher H. Knieper - Web page: https://patentgrep.com/patent/US20190172274A1 ## CPC - G07C 5/0808: {Diagnosing performance data (testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005)} - F16H 59/00: Control inputs to {control units of} change-speed- or reversing-gearings for conveying rotary motion - F16H 61/12: Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures} - H02M 7/5387: in a bridge configuration - F16H 2061/0037: {characterised by controlled fluid supply to lubrication circuits of the gearing} - F16H 2061/1208: {with diagnostic check cycles; Monitoring of failures} - G07C 5/008: {communicating information to a remotely located station (transmission systems for measured values G08C)} - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - F16H: GEARING - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract A vehicle including a fluidic subsystem composed of an electric motor, a motor driver and a fluidic pump that is disposed in a fluidic circuit of the vehicle is described. A controller includes an instruction set that is executable to determine operating parameters associated with the fluidic subsystem, and determine a plurality of power efficiency parameters for the fluidic subsystem based upon the operating parameters. The power efficiency parameters include a hydraulic power efficiency, an electro-mechanical power efficiency and an electric power efficiency. The controller can determine a state of health for the fluidic subsystem based upon the power efficiency parameters, and detect a fault in the fluidic subsystem when the state of health is less than a threshold state of health. The fault can be communicated to a vehicle operator. ## Claims ### Claim 1 A method for monitoring a fluidic subsystem disposed on a vehicle, the fluidic subsystem including an electric motor electrically connected to a motor driver and rotatably connected to a fluidic pump that is disposed in a fluidic circuit, the method comprising: determining operating parameters associated with the fluidic subsystem; determining a plurality of power efficiency parameters for the fluidic subsystem based upon the operating parameters, wherein the power efficiency parameters include a hydraulic power efficiency, an electro-mechanical power efficiency and an electric power efficiency; determining a state of health for the fluidic subsystem based upon the power efficiency parameters; detecting a fault in the fluidic subsystem when the state of health is less than a threshold state of health; and communicating the fault to an on-board controller. ### Claim 2 (depends on 1) The method of claim 1, wherein determining the electric power efficiency comprises: determining DC electric power including a DC current and a DC voltage delivered to the motor driver; determining AC electric power including an AC current and an AC voltage delivered from the motor driver to the electric motor; and determining the electric power efficiency based upon a ratio of the DC electric power and the AC electric power. ### Claim 3 (depends on 1) The method of claim 1, wherein determining the electro-mechanical power efficiency comprises: determining AC electric power including an AC current and an AC voltage delivered from the motor driver to the electric motor; determining mechanical power generated by the electric motor, including a torque output and a rotational speed of the electric motor; and determining the electro-mechanical power efficiency based upon a ratio of the AC electric power and mechanical power. ### Claim 4 (depends on 1) The method of claim 1, wherein determining the hydraulic power efficiency comprises: determining mechanical power transferred from the electric motor to the fluidic pump, including a torque output and a rotational speed of the electric motor; determining hydraulic power output from the fluidic pump, including a pressure differential and a mass flowrate in the fluidic circuit; and determining the hydraulic power efficiency based upon a ratio of the mechanical power and the hydraulic power. ### Claim 5 (depends on 1) The method of claim 1, wherein determining the state of health (SOH) for the fluidic subsystem based upon the power efficiency parameters comprises determining a first SOH parameter based upon the hydraulic power efficiency and a nominal hydraulic power efficiency; determining a second SOH parameter based upon the electro-mechanical power efficiency and a nominal electro-mechanical power efficiency; determining a third SOH parameter based upon the electric power efficiency and a nominal electric power efficiency; and determining the SOH for the fluidic subsystem based upon the first SOH parameter, the second SOH parameter and the third SOH parameter. ### Claim 6 (depends on 1) The method of claim 1, further comprising determining a fault in an element of the fluidic subsystem based upon the power efficiency parameters. ### Claim 7 (depends on 6) The method of claim 6, comprising determining a fault associated with the motor driver when the electric power efficiency is less than an associated threshold efficiency level. ### Claim 8 (depends on 6) The method of claim 6, comprising determining a fault associated with the electric motor when the electro-mechanical power efficiency is less than an associated threshold efficiency level. ### Claim 9 (depends on 6) The method of claim 6, comprising determining a fault associated with the fluidic pump when the hydraulic power efficiency is less than an associated threshold efficiency level. ### Claim 10 (depends on 1) The method of claim 1, wherein communicating the fault to an on-board controller further comprises communicating the fault to a human-machine interface device in communication with the on-board controller. ### Claim 11 (depends on 1) The method of claim 1, further comprising communicating the fault to an off-vehicle controller via a telematics device in communication with the on-board controller. ### Claim 12 (depends on 1) The method of claim 1, further comprising isolating the fault in the fluidic subsystem to one of the electric motor, the motor driver or the fluidic pump based upon the plurality of power efficiency parameters. ### Claim 13 A vehicle including a fluidic subsystem disposed thereon, comprising: an electric motor electrically connected to a motor driver and rotatably connected to a fluidic pump that is disposed in a fluidic circuit of the vehicle, a controller in communication with the electric motor, the motor driver and the fluidic circuit, the controller including an instruction set, the instruction set executable to: determine operating parameters associated with the fluidic subsystem; determine a plurality of power efficiency parameters for the fluidic subsystem based upon the operating parameters, wherein the power efficiency parameters include a hydraulic power efficiency, an electro-mechanical power efficiency and an electric power efficiency; determine a state of health for the fluidic subsystem based upon the power efficiency parameters; detect a fault in the fluidic subsystem when the state of health is less than a threshold state of health; and communicate the fault to a vehicle operator. ### Claim 14 (depends on 13) The vehicle of claim 13, further comprising a telematics device, wherein the controller is configured to communicate the fault to an off-board controller via the telematics device. ### Claim 15 (depends on 13) The vehicle of claim 13, further comprising the instruction set executable to isolate the fault in the fluidic subsystem to one of the electric motor, the motor driver or the fluidic pump based upon the plurality of power efficiency parameters. ### Claim 16 A method for monitoring a fluidic subsystem disposed on a vehicle, wherein the fluidic subsystem includes an electric motor electrically connected to a motor driver and rotatably connected to a fluidic pump that is disposed in a fluidic circuit, and the vehicle includes a telematics device, the method comprising: monitoring operating parameters associated with the fluidic subsystem; communicating, via the telematics device, the parameters associated with operation of the fluidic subsystem to a remote server; and determining, via the remote server, a plurality of power efficiency parameters for the fluidic subsystem based upon the operating parameters, wherein the power efficiency parameters include a hydraulic power efficiency, an electro-mechanical power efficiency and an electric power efficiency; determining, via the remote server, a state of health for the fluidic subsystem based upon the power efficiency parameters; detecting, via the remote server, a fault in the fluidic subsystem when the state of health is less than a threshold state of health; isolating the fault in the fluidic subsystem to one of the electric motor, the motor driver or the fluidic pump based upon the plurality of power efficiency parameters; and communicating the isolated fault to an on-vehicle controller.