# US 2020/0400084 A1 · Methods and system for determining engine speed > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0400084 A1 - Document ID: US20200400084A1 - Status: Published application - Kind: A1 - Application number: 16/446,447 - Filed: 2019-06-19 - Published: 2020-12-24 - Earliest claimed: 2019-06-19 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Scott Steadmon Thompson; Vincent Martinez; John Eric Rollinger; David Lew; Nicholas Herhusky - Web page: https://patentgrep.com/patent/US20200400084A1 ## CPC - F02D 29/06: peculiar to engines driving electric generators - B60K 25/02: directly from an engine shaft - F02D 28/00: Program control of engines - F02D 31/001: {Electric control of rotation speed} - F02D 41/021: {Introducing corrections for particular conditions exterior to the engine (conjoint control of vehicle sub-units for propelling the vehicle B60W30/18)} - F02D 41/2409: {Addressing techniques specially adapted therefor} - F02D 41/28: Interface circuits - F02N 11/04: the motors being associated with current generators - B60K 2025/005: {driven by electric motors forming part of the propulsion unit} - B60K 2025/024: {with variable ratio} - B60W 2710/305: target power to auxiliaries - B60Y 2400/604: AC Machines, e.g. asynchronous motors - F02D 41/0097: {using means for generating speed signals} - F02D 2200/70: said parameters being related to the vehicle exterior - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY ## Abstract Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, a speed of the engine may be adjusted so that the engine provides power to drive the electric machine without generating numerous rapid engine speed changes in a short amount of time. ## Claims ### Claim 1 A powertrain operating method, comprising: propelling a vehicle via an engine; storing a plurality of requested instantaneous engine rotational speed values in a memory buffer via a controller, the memory buffer including a plurality of unique memory locations, each of the plurality of unique memory locations including one of the plurality of requested instantaneous engine rotational speed values; shifting at least one of the plurality of requested instantaneous engine rotational speed values from a first of the unique memory locations to a second of the unique memory locations in response to a buffer step time expiring; and adjusting engine rotational speed to a maximum requested instantaneous engine rotational speed value stored in the buffer via the controller. ### Claim 2 (depends on 1) The method of claim 1, further comprising determining the plurality of requested instantaneous engine speed values from a plurality of requested instantaneous electric machine speed values. ### Claim 3 (depends on 2) The method of claim 2, where the requested instantaneous electric machine speed values are a function of an amount of electric power consumed via external electric power consumers. ### Claim 4 (depends on 3) The method of claim 3, where the external electric power consumers are off-board of a vehicle and where the engine is on-board a vehicle. ### Claim 5 (depends on 1) The method of claim 1, further comprising adjusting the engine rotational speed via an engine torque actuator. ### Claim 6 (depends on 1) The method of claim 1, further comprising applying a moving average filter to the plurality of requested instantaneous engine rotational speed values. ### Claim 7 (depends on 1) The method of claim 1, further comprising shifting a new requested instantaneous engine rotational speed value into one of the plurality of unique memory locations in response to the buffer step time expiring. ### Claim 8 (depends on 7) The method of claim 7, further comprising shifting one of the plurality of requested instantaneous engine rotational speed values out of the plurality of unique memory locations in response to the buffer step time expiring. ### Claim 9 A powertrain operating method, comprising: propelling a vehicle via an engine; and adjusting a rotational speed of the engine via a controller responsive to an amount of electrical power output from a direct current to alternating current converter to one or more electric power consumers, and where the rotational speed of the engine is adjusted to a maximum instantaneous engine rotational speed included in a memory buffer that includes a plurality of requested instantaneous engine rotational speeds. ### Claim 10 (depends on 9) The method of claim 9, where the plurality of requested instantaneous engine rotational speeds are stored in the memory buffer responsive to a buffer time length. ### Claim 11 (depends on 10) The method of claim 10, where the memory buffer stores one of the plurality of requested instantaneous engine rotational speeds for a predetermined buffer time duration. ### Claim 12 (depends on 10) The method of claim 10, where a predetermined buffer step time separates each value of the plurality of requested instantaneous engine rotational speeds stored in the memory buffer. ### Claim 13 (depends on 9) The method of claim 9, further comprising rate limiting the rotational speed of the engine. ### Claim 14 (depends on 13) The method of claim 13, where the rate limiting includes reducing a rate of lowering the rotational speed of the engine to less than a threshold. ### Claim 15 A system, comprising: an engine; an electric machine mechanically coupled to the engine; and a controller including executable instructions stored in non-transitory memory to adjust a rotational speed of the engine via a controller responsive to an amount of electrical power output from a direct current to alternating current converter to one or more electric power consumers, and where the rotational speed of the engine is adjusted to a maximum instantaneous engine rotational speed included in a memory buffer that includes a plurality of requested instantaneous engine rotational speeds ### Claim 16 (depends on 15) The system of claim 15, further comprising additional instructions to filter each of the plurality of requested instantaneous engine rotational speeds via a moving average digital filter. ### Claim 17 (depends on 16) The system of claim 16, further comprising additional instructions to rate limit the maximum instantaneous engine rotational speed. ### Claim 18 (depends on 15) The system of claim 15, further comprising additional instructions to shift values in the memory buffer. ### Claim 19 (depends on 18) The system of claim 18, where the values are shifted in a first in to first out order. ### Claim 20 (depends on 19) The system of claim 19, where values are shifted in response to a buffer step time expiring.