Method and arrangement in a hybrid vehicle for improving battery state-of-charge control and minimizing driver perceptible disturbances

• US 6,336,063 B1
• Filed: 11/30/2000
• Issued: 01/01/2002
• Est. Priority Date: 10/31/2000
• Status: Expired due to Term

• Current Assignee: Volvo Car Corporation (AB Volvo)
• Original Assignee: Volvo Car Corporation (AB Volvo)
• Inventors: Lennevi, Jerker
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): HERNANDEZ, OLGA
• Application Number:
  US09/728,472
• Time in Patent Office: 397 Days
• Field of Search: 701/22, 701/110, 477/7, 477/14, 477/91, 180/65.1, 340/636, 340/648, 307/10.7, 320/106
• US Class Current: 701/22
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 1/04 of the electric storage means for propulsion exchanging batteries for electric propulsion of vehicles B60L53/80; for auxiliary purposes only B60R16/04; supplying batteries to, or removing batteries from, vehicles B60S5/06
• CPC Class Codes: B60K 2001/005 the electric storage means
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/383 One-way clutches or freewheel devices
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 2260/42 by adaptive correction
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 : including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 : including control of change-speed gearings
• CPC Class Codes: B60W 10/26 : for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 : Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 : Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2050/0006 : Digital architecture hierarchy
• CPC Class Codes: B60W 2050/0012 : Feedforward or open loop systems
• CPC Class Codes: B60W 2050/0022 : Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2050/0045 : using databus protocols
• CPC Class Codes: B60W 2510/0638 : Engine speed
• CPC Class Codes: B60W 2510/0657 : Engine torque
• CPC Class Codes: B60W 2510/0661 : Torque change rate
• CPC Class Codes: B60W 2510/068 : Engine exhaust temperature
• CPC Class Codes: B60W 2510/081 : Speed
• CPC Class Codes: B60W 2510/083 : Torque
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2520/10 : Longitudinal speed
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2710/0616 : Position of fuel or air injector
• CPC Class Codes: B60W 2710/0622 : Air-fuel ratio
• CPC Class Codes: B60W 2710/0644 : Engine speed
• CPC Class Codes: B60W 2710/065 : Idle condition
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/105 : Output torque
• CPC Class Codes: B60W 2710/1055 : Output torque change rate
• CPC Class Codes: B60W 2710/1061 : Output power
• CPC Class Codes: B60W 30/18027 : Drive off, accelerating from standstill
• CPC Class Codes: B60W 50/0097 : Predicting future conditions
• CPC Class Codes: F02D 2250/18 : Control of the engine output torque
• CPC Class Codes: F02D 41/021 : Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02N 19/00 : Starting aids for combustion engines, not otherwise provided for
• CPC Class Codes: H01M 10/44 : Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 : Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/613 : Cooling or keeping cold
• CPC Class Codes: H01M 10/625 : Vehicles
• CPC Class Codes: H01M 10/64 : characterised by the shape of the cells
• CPC Class Codes: H01M 10/6557 : arranged between the cells
• CPC Class Codes: H01M 10/6569 : Fluids undergoing a liquid-gas phase change or transition, e.g. evaporation or condensation heat pipes H01M10/6552
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration
• CPC Class Codes: Y10S 903/907 : Electricity storage, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/913 : One way
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio

Abstract

Method for minimizing driver perceptible drive train disturbances during take-off in a hybrid electric vehicle when maximized power is often desired is disclosed. The method includes sensing an actual state-of-charge (SOC) value of a battery in a hybrid electric vehicle and a traveling velocity of the vehicle during take-off operation. The sensed actual SOC value is compared with a SOC reference value and computing a delta SOC value as a difference therebetween. A velocity-based SOC calibration factor is looked up that corresponds to the traveling velocity of the vehicle. A combination is utilized of the delta SOC value and the SOC calibration factor as a SOC feedback engine speed control instruction to an engine controller of the hybrid electric vehicle. A driver'"'"'s desired vehicular acceleration is sensed based on accelerator position. Maximum possible engine power generatable at the sensed vehicle speed is determined, as is a required power value from the power train of the vehicle to meet the driver'"'"'s desired vehicular acceleration. The maximum possible engine power generatable at the sensed vehicle speed is compared with the required power value and computing a delta power train requirement value as a difference therebetween. A velocity-based and accelerator position-based power calibration factor is looked-up that corresponds to the traveling velocity of the vehicle and the accelerator position. A combination of the delta power train requirement value and the power calibration factor is utilized as a power requirement feed-forward engine speed control instruction to an engine controller of the hybrid electric vehicle.

Claims

1. A method for minimizing driver perceptible drive train disturbances during take-off in a hybrid electric vehicle when maximized power is often desired, said method comprising:

sensing an actual state-of-charge (SOC) value of a battery in the hybrid electric vehicle and a traveling velocity of the vehicle during take-off operation;

comparing the sensed actual SOC value with a SOC reference value and computing a delta SOC value as a difference therebetween;

looking up a velocity-based SOC calibration factor corresponding to the traveling velocity of the vehicle;

utilizing a combination of the delta SOC value and the SOC calibration factor as a SOC feedback engine speed control instruction to an engine controller of the hybrid electric vehicle;

sensing a driver'"'"'s desired vehicular acceleration based on accelerator position;

determining maximum possible engine power generatable at the sensed vehicle speed;

determining a required power value from the power train of the vehicle to meet the driver'"'"'s desired vehicular acceleration;

comparing the maximum possible engine power generatable at the sensed vehicle speed with the required power value and computing a delta power train requirement value as a difference therebetween;

looking up a velocity-based and accelerator position-based power calibration factor corresponding to the traveling velocity of the vehicle and the accelerator position; and

utilizing a combination of the delta power train requirement value and the power calibration factor as a power requirement feed-forward engine speed control instruction to an engine controller of the hybrid electric vehicle.

2. The method as recited in claim 1 wherein the combination of the delta SOC value and the SOC calibration factor is by multiplication.

3. The method as recited in claim 1 wherein the combination of the delta power train requirement value and the power calibration factor is by multiplication.

4. The method as recited in claim 1 further comprising:

detecting a take-off vehicle operating condition in which maximized power is likely to be demanded from the drive train of the hybrid electric vehicle; and

preventing a sensed SOC discharge condition during the take-off operation due to motor utilization of battery power from triggering a battery charge condition which reduces engine torque available to power the drive train of the vehicle.

5. The method as recited in claim 1 further comprising:

detecting a take-off vehicle operating condition in which maximized power is likely to be demanded from the drive train of the hybrid electric vehicle; and

causing immediate acceleration of the engine'"'"'s operation beyond an optimized operational speed in anticipation of an actual maximized power demand.

6. The method as recited in claim 1 further comprising:

detecting a take-off vehicle operating condition in which maximized power is likely to be demanded from the drive train of the hybrid electric vehicle; and

causing a command to be issued from a generator controller, responsive to a sensed SOC discharge condition, to instruct immediate acceleration of the engine'"'"'s operation beyond an optimized operational speed thereby minimizing discharge of the battery.

7. The method as recited in claim 1 further comprising:

detecting a take-off vehicle operating condition in which maximized power is likely to be demanded from the drive train of the hybrid electric vehicle; and

causing a command to be issued from a generator controller, responsive to a sensed SOC discharge condition, instructing immediate acceleration of the engine'"'"'s operation beyond an optimized operational speed thereby commencing recharge of the battery.

8. The method as recited in claim 1 further comprising:

utilizing a preferred SOC reference value of fifty percent of battery total charge capacity.

9. The method as recited in claim 1 further comprising:

utilizing a preferred SOC reference value in a range of forty to sixty percent of battery total charge capacity.