# US 2015/0149005 A1 · Torque monitoring system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0149005 A1 - Document ID: US20150149005A1 - Status: Published application - Kind: A1 - Application number: 14/091,431 - Filed: 2013-11-27 - Published: 2015-05-28 - Earliest claimed: 2013-11-27 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Daniel Richard Luedtke; Fazal Urrahman Syed; Siwei Cheng - Web page: https://patentgrep.com/patent/US20150149005A1 ## CPC - B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed - B60L 3/12: Recording operating variables {; Monitoring of operating variables} - B60L 50/16: with provision for separate direct mechanical propulsion - B60L 50/61: by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles - B60L 58/30: for monitoring or controlling fuel cells - H02P 21/20: Estimation of torque - B60L 2240/423: Torque - B60L 2240/427: Voltage - B60L 2240/429: Current - B60L 2260/44: by parameter estimation - Y02T 10/62: Hybrid vehicles - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 10/72: Electric energy management in electromobility - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - Y10S 903/903: having energy storing means, e.g. battery, capacitor - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A method according to an exemplary aspect of the present disclosure includes, among other things, controlling a vehicle using an estimated torque of an electric machine, the estimated torque based on one or more parameters associated with the electric machine that are independent from measured current feedback. ## Claims ### Claim 1 A method, comprising: controlling a vehicle using an estimated torque of an electric machine, the estimated torque based on one or more parameters associated with the electric machine that are independent from measured current feedback. ### Claim 2 (depends on 1) The method as recited in claim 1, comprising the step of comparing the estimated torque to an expected torque. ### Claim 3 (depends on 2) The method as recited in claim 2, wherein the step of controlling the vehicle includes preventing operation of the vehicle if a difference between the estimated torque and the expected torque exceeds a predefined threshold. ### Claim 4 (depends on 2) The method as recited in claim 2, wherein the step of controlling the vehicle includes limiting operation of the vehicle if a difference between the estimated torque and the expected torque error exceeds a predefined threshold. ### Claim 5 (depends on 1) The method as recited in claim 1, wherein the one or more parameters include voltages. ### Claim 6 (depends on 1) The method as recited in claim 1, wherein the one or more parameters include inductances. ### Claim 7 (depends on 1) The method as recited in claim 1, wherein the one or more parameters include physical flux linkages. ### Claim 8 (depends on 1) The method as recited in claim 1, wherein the one or more parameters include resistances. ### Claim 9 (depends on 1) The method as recited in claim 1, wherein the one or more parameters include measured voltages of the electric machine. ### Claim 10 (depends on 1) The method as recited in claim 1, wherein the estimated torque is derived using the following equation: T em = 3  N pp 2  I q  ( λ m - ( L q - L d )  I d ) where: Npp is the number of pole-pairs, Iq and Id are the q-axis and d-axis currents, respectively, λm is the permanent magnet flux linkage, and Lq and Ld are the q-axis and d-axis inductances, respectively. ### Claim 11 A method, comprising: controlling a vehicle using an estimated torque of an electric machine, the estimated torque derived without measuring current feedback from the electric machine. ### Claim 12 (depends on 11) The method as recited in claim 11, wherein the estimated torque is derived from at least one of inductance estimates, voltage estimates, resistance estimates and physical flux linkage estimates associated with the electric machine. ### Claim 13 (depends on 11) The method as recited in claim 11, comprising: calculating the estimated torque of the electric machine; comparing the estimated torque to an expected torque; and performing the controlling step in response to a difference between the estimated torque and the expected torque exceeding a predefined threshold. ### Claim 14 (depends on 13) The method as recited in claim 13, wherein the step of performing the controlling step includes preventing operation of the vehicle. ### Claim 15 (depends on 13) The method as recited in claim 13, wherein the step of performing the controlling step includes limiting operation of the vehicle. ### Claim 16 A torque monitoring system, comprising: an electric machine; and a control unit configured to estimate a torque of said electric machine without measuring current feedback from said electric machine. ### Claim 17 (depends on 16) The system as recited in claim 16, wherein said control unit is configured to estimate said torque based on at least one of inductance estimates, voltage estimates, resistance estimates and physical flux linkage estimates associated with said electric machine. ### Claim 18 (depends on 16) The system as recited in claim 16, comprising a variable voltage converter in communication with said control unit. ### Claim 19 (depends on 16) The system as recited in claim 16, comprising an inverter connected to said electric machine by a plurality of windings. ### Claim 20 (depends on 16) The system as recited in claim 16, wherein said control unit employs the following torque equation to derive said torque: T em = 3  N pp 2  I q  ( λ m - ( L q - L d )  I d ) where: Npp is the number of pole-pairs, Iq and Id are the q-axis and d-axis currents, respectively, λm is the permanent magnet flux linkage, and Lq and Ld are the q-axis and d-axis inductances, respectively.