# US 11,993,248 B2 · Method for controlling series hybrid vehicle, and series hybrid vehicle

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- Number: US 11,993,248 B2
- Document ID: US11993248B2
- Status: Granted
- Kind: B2
- Application number: 17/628,915
- Filed: 2020-07-29
- Published: 2022-11-17
- Granted: 2024-05-28
- Earliest claimed: 2020-07-29
- Assignees: Nissan Motor Co., Ltd.
- Applicants: Nissan Motor Co., Ltd.
- Inventors: Kiyoshi Hoshi; Yohei Nakamura; Azusa Kobayashi
- Web page: https://patentgrep.com/patent/US11993248B2

## CPC

- B60K 6/46: Series type
- B60W 20/17: for noise reduction
- B60K 6/40: characterised by the assembly or relative disposition of components
- B60K 6/405: Housings
- B60W 10/06: including control of combustion engines
- B60W 10/08: including control of electric propulsion units, e.g. motors or generators
- B60W 10/18: including control of braking systems
- B60W 10/184: with wheel brakes
- B60W 20/11: using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance {(utilising navigation and traffic information in the control strategy B60W20/12)}
- B60W 20/14: in conjunction with braking regeneration
- B60W 30/18127: {Regenerative braking}
- B60W 30/1882: {characterised by the working point of the engine, e.g. by using engine output chart}
- B60W 40/12: related to parameters of the vehicle itself {, e.g. tyre models}
- B60W 2030/206: {related or induced by the engine}
- B60W 2510/0638: Engine speed
- B60W 2510/0676: Engine temperature
- B60W 2510/081: Speed
- B60W 2510/083: Torque
- B60W 2520/10: Longitudinal speed
- B60W 2530/12: Catalyst or filter state
- B60W 2540/10: Accelerator pedal position
- B60W 2540/12: Brake pedal position
- B60W 2710/0644: Engine speed
- B60W 2710/0666: Engine torque
- B60W 2710/081: Speed
- B60W 2710/083: Torque
- B60W 2710/182: Brake pressure, e.g. of fluid or between pad and disc
- Y02T 10/62: Hybrid vehicles
- 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
- 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
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A control method controls a series hybrid vehicle in which a drive motor and an internal combustion engine are supported in a vehicle body via a plurality of mount members in an integrated state. The control method using a controller generates electric power using an electric power generation motor, and drives the electric power generation motor using motive power of the internal combustion engine. The control method drives a drive wheel with the drive motor using the generated electric power, and causes the drive motor to generate regenerative torque during deceleration. In the control method, the regenerative torque is generated by the drive motor such that an upper limit of the regenerative torque is restricted to a magnitude at which an engine rotational speed where resonance occurs on the vehicle body floor.

## Claims

### Claim 1

A control method for controlling a series hybrid vehicle having a drive motor and an internal combustion engine supported in a vehicle body via a plurality of mount members in an integrated state, the method using a controller and comprising:
driving an electric power generation motor by motive power of the internal combustion engine to generate electric power by the electric power generation motor;
controlling the internal combustion engine such that an engine rotational speed of the internal combustion engine is equal or smaller than an upper limit rotational speed;
using the electric power generated to drive the drive motor to drive a drive wheel;
generating a regenerative torque by the drive motor in response to a deceleration request during deceleration; and
restricting the regenerative torque such that the regenerative torque does not exceed a regenerative torque upper limit value when the drive motor generates the regenerative torque in response to the deceleration request while the electric power generation motor is driven by the internal combustion engine,
the regenerative torque upper limit value being calculated such that the regenerative torque is restricted to a magnitude at which a floor vibration generation region is lower than the upper limit rotational speed of the internal combustion engine, the floor vibration generation region being a region of engine rotational speeds at which resonance occurs in a floor of the vehicle body, the floor vibration generation region varying according to the regenerative torque.

### Claim 2 (depends on 1)

The series hybrid vehicle control method according to claim 1, further comprising
calculating a spring constant of an engine mount, which is one of the plurality of mount members, for a case where a combustion excitation force frequency at an upper limit rotational speed of the internal combustion engine during generation of the electric power and a characteristic frequency of the internal combustion engine elastically supported by the engine mount are equal;
calculating a compression amount of the engine mount when the calculated spring constant is employed; and
setting a torque of the drive motor when the compression amount is employed as the regenerative torque upper limit value.

### Claim 3 (depends on 2)

The series hybrid vehicle control method according to claim 2, wherein
the regenerative torque upper limit value is reduced as the upper limit rotational speed decreases.

### Claim 4 (depends on 2)

The series hybrid vehicle control method according to claim 2, wherein
the compression amount of the engine mount increases as the regenerative torque increases; and
the floor vibration generation region becomes a higher engine rotational speed region as the compression amount of the engine mount increases.

### Claim 5

A series hybrid vehicle comprising:
an internal combustion engine;
an electric power generation motor that is driven by motive power of the internal combustion engine;
a drive motor that is driven by electric power generated by the electric power generation motor; and
a controller that controls the internal combustion engine such that an engine rotational speed of the internal combustion engine is equal or smaller than an upper limit rotational speed and controls the drive motor to generate regenerative torque in response to a deceleration request during deceleration,
the drive motor and the internal combustion engine being supported in a vehicle body via a plurality of mount members in an integrated state,
the controller being configured to restrict the regenerative torque such that the regenerative torque does not exceed a regenerative torque upper limit value when the drive motor generates the regenerative torque in response to the deceleration request while the electric power generation motor is driven by the internal combustion engine,
the controller being configured to calculate the regenerative torque upper limit value such that the regenerative torque is restricted to a magnitude at which a floor vibration generation region is lower than the upper limit rotational speed of the internal combustion engine, the floor vibration generation region being a region of engine rotational speeds at which resonance occurs in a floor of the vehicle body, the floor vibration generation region varying according to the regenerative torque.

### Claim 6 (depends on 5)

The series hybrid vehicle according to claim 5, wherein
the controller if further configured to:
control the internal combustion engine such that the engine rotational speed is equal to or larger than a lower limit rotational speed; and
increase the lower limit rotational speed when the drive motor generates the regenerative torque in response to the deceleration request while the electric power generation motor is driven by the internal combustion engine.

### Claim 7 (depends on 6)

The series hybrid vehicle according to claim 6, wherein
the controller is further configured to give priority to controlling the internal combustion engine such that the engine rotational speed is equal to or smaller than the upper limit rotational speed when the upper limit rotational speed is equal to or smaller than the lower limit rotational speed.

### Claim 8 (depends on 1)

The series hybrid vehicle control method according to claim 1, further comprising:
controlling the internal combustion engine such that the engine rotational speed is equal to or larger than a lower limit rotational speed; and
increasing the lower limit rotational speed when the drive motor generates the regenerative torque in response to the deceleration request while the electric power generation motor is driven by the internal combustion engine.

### Claim 9 (depends on 8)

The series hybrid vehicle control method according to claim 8, further comprising:
giving priority to controlling the internal combustion engine such that the engine rotational speed is equal to or smaller than the upper limit rotational speed when the upper limit rotational speed is equal to or smaller than the lower limit rotational speed.