# US 8,569,902 B2 · Methods and systems for engine starting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,902 B2 - Document ID: US8569902B2 - Status: Granted - Kind: B2 - Application number: 12/913,526 - Filed: 2010-10-27 - Published: 2012-05-03 - Granted: 2013-10-29 - Earliest claimed: 2010-10-27 - Assignees: Ford Global Technologies, LLC - Applicants: Alex O'Connor Gibson; John Anthony DeMarco; Allan Roy Gale; Vincent John Boscheratto - Inventors: Alex O'Connor Gibson; John Anthony DeMarco; Allan Roy Gale; Vincent John Boscheratto - Web page: https://patentgrep.com/patent/US8569902B2 ## CPC - F02N 11/08: Circuits specially adapted for starting of engines - B60L 1/003: {to auxiliary motors, e.g. for pumps, compressors} - 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 50/16: with provision for separate direct mechanical propulsion - B60L 58/20: having different nominal voltages - F02N 11/0866: {comprising several power sources, e.g. battery and capacitor or two batteries} - F02N 11/087: {Details of the switching means in starting circuits, e.g. relays or electronic switches} - B60L 2240/421: Speed - B60L 2240/423: Torque - B60L 2240/441: Speed - B60L 2240/445: Temperature - B60L 2240/547: Voltage - F02N 2011/0888: {DC/DC converters} - F02N 2250/02: Battery voltage drop at start, e.g. drops causing ECU reset - 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 - F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A system for improving engine starting is disclosed. In one example, an engine starting is improved by providing a predictable load to the engine during engine starting. The predictable load may be provided by controlling alternator field voltage during the engine start. ## Claims ### Claim 1 A vehicle system, comprising: an engine that is selectively shut-down during engine idle-stop conditions; a battery; a starter; a DC/DC converter electrically coupled to the battery, the DC/DC converter configured to provide a regulated voltage output; an alternator including an alternator field coil excitation circuit, the alternator field coil excitation circuit electrically coupled to an output of the DC/DC converter during an engine start, the alternator mechanically coupled to the engine; and a controller with computer readable instructions for, during an engine restart from idle-stop conditions, adjusting engine torque via at least one torque actuator. ### Claim 2 (depends on 1) The vehicle system of claim 1, wherein the starter is powered by the battery during the engine start. ### Claim 3 (depends on 1) The vehicle system of claim 1, wherein an armature of the alternator is in electrical communication with the battery, the battery supplying power to the DC/DC converter, and wherein the alternator field coil excitation circuit is electrically buffered from the battery via the DC/DC converter. ### Claim 4 (depends on 1) The vehicle system of claim 1, wherein an output voltage of the DC/DC converter is greater than a voltage of the battery during engine cranking. ### Claim 5 (depends on 1) The vehicle system of claim 1, further comprising a diode in a circuit that electrically couples the battery to the alternator field coil excitation circuit, a cathode of the diode oriented towards the alternator field coil excitation circuit, and an anode of the diode oriented towards the battery, the diode electrically buffering the alternator field coil excitation circuit from the battery by limiting current flow in a direction from the alternator field coil excitation circuit to the battery. ### Claim 6 (depends on 5) The vehicle system of claim 5, further comprising a switch coupled in parallel with the DC/DC converter, the controller including further instructions for, during the engine restart, opening the switch to electrically buffer the alternator field coil excitation circuit from the battery; and following the engine restart, closing the switch to bypass a buffer circuit between the alternator field coil excitation circuit and the battery. ### Claim 7 (depends on 1) The vehicle system of claim 1, wherein the DC/DC converter is further electrically coupled to one or more auxiliary electrical loads including interior vehicle lighting. ### Claim 8 (depends on 1) The vehicle system of claim 1, further comprising a power steering system electrically coupled to the alternator, the controller including further instructions for controlling a current supplied to the power steering system by the alternator during the engine start. ### Claim 9 A method of controlling a vehicle system including an engine that is selectively shut-down during engine idle-stop conditions, comprising: during an engine start, electrically buffering an alternator field coil excitation circuit of an alternator from a battery supplying power to a starter; and maintaining an alternator field coil excitation circuit input voltage to control a load applied to the engine via an alternator rotor. ### Claim 10 (depends on 9) The method of claim 9, further comprising, bypassing the electrical buffering of the field coil excitation circuit of the alternator after a voltage at the battery is greater than a threshold voltage. ### Claim 11 (depends on 10) The method of claim 10, wherein maintaining the alternator field coil excitation circuit input voltage includes maintaining the alternator field coil excitation input voltage via a DC/DC converter. ### Claim 12 (depends on 9) The method of claim 9, wherein the electrical buffering is via a switch.