# US 9,435,461 B2 · Controller of electromagnetic valve driving circuit and abnormality diagnosing method for electromagnetic valve driving circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,461 B2 - Document ID: US9435461B2 - Status: Granted - Kind: B2 - Application number: 14/373,395 - Filed: 2013-02-22 - Published: 2015-01-15 - Granted: 2016-09-06 - Earliest claimed: 2012-03-29 - Assignees: Aisin Aw Co., Ltd. - Applicants: Aisin Aw Co., Ltd. - Inventors: Kenta Akazaki; Moritaka Fukuda; Kohei Kondo; Kento Yamashita - Web page: https://patentgrep.com/patent/US9435461B2 ## CPC - F16H 61/0006: {Electronic control units for transmission control, e.g. connectors, casings or circuit boards} - F16H 61/12: Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures} - F16K 31/0675: {Electromagnet aspects, e.g. electric supply therefor} - B60Y 2300/192: Power-up or power-down of the driveline, e.g. start up of a cold engine - B60Y 2300/45: Engine shutdown at standstill - F16H 2312/20: Start-up or shut-down - G01R 31/2829: {Testing of circuits in sensor or actuator systems (testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844)} - G01R 31/72: Testing of electric windings (testing of transformers G01R31/62) - F16H: GEARING - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A controller of an electromagnetic valve driving circuit include a switching element connected to an electromagnetic valve solenoid, a cutoff circuit for cutting off a connection between a power supply and the switching element, and a current detecting unit for detecting a current flowing in the solenoid. The controller includes an abnormality diagnosing unit for outputting a cutoff command to the cutoff circuit for cutting off the connection between the power supply and the switching element, and outputting a switching command causing the switching element to perform a switching operation when a predetermined diagnosis condition is satisfied, and determining that the cutoff circuit normally operates when the solenoid current is less than a threshold value and determining that the cutoff circuit operates abnormally when the solenoid current is greater than or equal to the threshold value while outputting the cutoff command and the switching command. ## Claims ### Claim 1 A controller of an electromagnetic valve driving circuit including a switching element connected to a solenoid of an electromagnetic valve, a cutoff circuit capable of cutting off a connection between a power supply and the switching element, and current sensor for detecting a solenoid current flowing in the solenoid, the controller comprising: abnormality diagnosing means for outputting a cutoff command for cutting off the connection between the power supply and the switching element to the cutoff circuit and outputting a switching command for causing the switching element to perform a switching operation to the switching element when a predetermined diagnosis condition is satisfied, and determining that the cutoff circuit normally operates when the detected solenoid current is less than a threshold value and determining that the cutoff circuit does not normally operate when the detected solenoid current is greater than or equal to the threshold value while outputting the cutoff command and the switching command. ### Claim 2 (depends on 1) The controller of an electromagnetic valve driving circuit according to claim 1, wherein the electromagnetic valve is an electromagnetic valve that is used to supply an operating fluid to an engagement element of a transmission, and the switching command is a command for causing the switching element to perform a switching operation enabling a predetermined current to flow in the solenoid when the power supply and the switching element are connected to each other. ### Claim 3 (depends on 2) The controller of an electromagnetic valve driving circuit according to claim 2, wherein the predetermined current is a current smaller than a minimum current required for engagement of the engagement element. ### Claim 4 (depends on 1) The controller of an electromagnetic valve driving circuit according to claim 1, further comprising: transmission control means for outputting the switching command for causing the switching element to perform the switching operation with a target duty ratio which is obtained using a feedforward term based on a target current to flow in the solenoid and a feedback term for cancelling a difference between the target current and the detected solenoid current when forming a shift speed of the transmission, wherein the abnormality diagnosing means is means for outputting the switching command for causing the switching element to perform the switching operation with a target duty ratio which is obtained using only the feedforward term without using the feedback term. ### Claim 5 (depends on 1) The controller of an electromagnetic valve driving circuit according to claim 1, wherein the abnormality diagnosing means does not determine whether the cutoff circuit normally operates when an abnormality occurs in the solenoid. ### Claim 6 (depends on 1) The controller of an electromagnetic valve driving circuit according to claim 1, wherein the cutoff circuit is a circuit capable of cutting off connections between the power supply and a plurality of the switching elements connected to the solenoids of a plurality of the electromagnetic valves, the current sensor includes multiple sensors for detecting a plurality of solenoid currents flowing in the plurality of solenoids, and the abnormality diagnosing means is means for outputting the switching command to the plurality of switching elements and determining whether the cutoff circuit normally operates using the plurality of detected solenoid currents. ### Claim 7 (depends on 1) The controller of an electromagnetic valve driving circuit according to claim 1, wherein the cutoff circuit is a circuit in which a plurality of cutoff portions capable of cutting off the connection between the power supply and the switching element are arranged in series, and the abnormality diagnosing means is means for determining whether each of the plurality of cutoff portions normally operates. ### Claim 8 (depends on 1) The controller of an electromagnetic valve driving circuit according to claim 1, wherein the predetermined diagnosis condition is a condition that is satisfied when an ignition switch of a vehicle is turned off. ### Claim 9 An abnormality diagnosing method of an electromagnetic valve driving circuit including a switching element connected to a solenoid of an electromagnetic valve, a cutoff circuit capable of cutting off a connection between a power supply and the switching element, and current sensor for detecting a solenoid current flowing in the solenoid, the method comprising: outputting a cutoff command for cutting off the connection between the power supply and the switching element to the cutoff circuit and outputting a switching command for causing the switching element to perform a switching operation to the switching element when a predetermined diagnosis condition is satisfied , and determining that the cutoff circuit normally operates when the detected solenoid current is less than a threshold value and determining that the cutoff circuit does not normally operate when the detected solenoid current is greater than or equal to the threshold value while outputting the cutoff command and the switching command.