Motor drive control apparatus

• US 6,373,206 B1
• Filed: 03/30/2000
• Issued: 04/16/2002
• Est. Priority Date: 03/31/1999
• Status: Expired due to Term

• Current Assignee: Suzuki Motor Corporation
• Original Assignee: Suzuki Motor Corporation
• Inventors: Morimoto, Kazuhiko, Omata, Yoshiaki
• Primary Examiner(s): Fletcher, Marlon T.
• Application Number:
  US09/539,424
• Time in Patent Office: 747 Days
• Field of Search: 318/139-148, 318/151-153, 318/157, 310/75.R, 310/76-77, 310/98, 123/179.1, 123/179.3, 123/179.4, 290/17, 290/21, 290/24-25, 290/27-28, 290/36.R, 290/37.R, 290/37.A, 290/38.R, 290/40.R, 180/65.4
• US Class Current: 318/139
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• 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 10/26 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/905 Combustion engine
• CPC Class Codes: Y10S 903/909 Gearing
• CPC Class Codes: Y10S 903/919 Stepped shift
• CPC Class Codes: Y10S 903/951 Assembly or relative location of components

Abstract

An electrical motor having a drive function and a power generating function is directly connected to an engine mounted on a vehicle. The vehicle has a starter connected to the engine. A motor control means for controlling the drive of the motor in cooperation with driving the starter and in accordance with an operating state of the engine in starting the engine to ensure firm starting performance of the engine, to promote durability of a starter and to simplify control of a motor to thereby promote durability of the control of the motor.

Claims

1. A motor drive control apparatus for vehicle including an electric motor having a driving function and a power generating function directly connected to an internal combustion engine, a main battery providing power to and receiving electrical power from said electric motor, a starter connected to the engine and powered by a sub-battery, said motor drive control apparatus comprising motor control means for controlling the electric motor in cooperation with driving of the starter and in accordance with an operating state of the engine, and wherein the motor drive control apparatus simultaneously drives the starter with the sub-battery and the electric motor with the main battery,

wherein the motor control means for supplying a drive power to the motor includes at least two conditions for stopping the supply drive power to the motor, wherein the two conditions are as follows:

(1) a main battery voltage of a main battery charged by power generated by the motor is less than a set voltage; and

(2) a drive time period of the motor exceeds a set time period,

said motor control means stopping drive power to the motor when at least one of the stopping conditions is established.

2. The motor drive control apparatus according to claim 1, wherein the motor control means includes further conditions for stopping the supply of drive power to the motor as follows:

(1) an engine rotational number of the engine exceeds a set rotational number;

(2) vehicle speed of the vehicle exceeds a set vehicle speed; and

(3) the starter is stopped,

said motor control means stopping drive power to the motor when at least one of the stopping conditions is established.

3. The motor drive control apparatus according to claim 1, wherein the motor control means requires a disengaged state for a transmission connected to the engine as a drive permitting condition to permit drive power to the electric motor.

4. The motor drive control apparatus according to claim 1, wherein the motor control means is provided for setting a starting torque map for the electric motor from an engine rotational number and an engine load and driving the motor using a torque value searched from the starting torque map in cooperation with driving the starter in starting the engine.

5. A vehicle including a starter connected to an internal combustion engine and powered by a sub-battery, a motor drive control apparatus including motor control means to control a driving function and a power generating function of an electric motor, the electric motor being directly connected to the engine and electrically connected to a main battery for providing power to and receiving electrical power from said electric motor,

means for sensing a voltage condition of the main battery, the motor control means permitting operation of the electric motor when the voltage condition of the main battery is sufficient to drive the motor, and a clutch switch for detecting if the vehicle transmission is in an engaged condition, the motor control means operating the electric motor and the starter when the starter switch is on, and the voltage and transmission conditions are met,

the means for sensing a voltage condition of the main battery sensing battery voltage for discontinuing operation of the electric motor if the main battery voltage drops to a predetermined voltage;

an engine rotational speed sensor for discontinuing operation of the electric motor when engine rotational speed is greater than a predetermined engine rotational speed;

a vehicle speed sensor for discontinuing operation of the electric motor when vehicle speed is greater than a predetermined vehicle speed, and

starter switch sensing means for discontinuing operation of the electric motor when the starter switch is turned off.

6. The vehicle of claim 5, including timing means for discontinuing operation of the electric motor when a continuous drive time for the electric motor exceeds a predetermined time.

7. The vehicle of claim 5, wherein the motor drive control apparatus simultaneously drives the starter with the sub-battery and the electric motor with the main battery.

8. The vehicle of claim 5, including a load sensor for measuring engine load, wherein the motor control means selects a value from a starting torque map in response to the engine rotational speed and the engine load to control the amount of energization of the electric motor by the main battery depending on the selected value.

9. A method of controlling a starter and an electric motor for assisting the starter to start a vehicle, the starter being connected to an engine and powered by a sub-battery, the electric motor connected to the engine and having a driving function and a power generating function, and a main battery for providing power to and receiving electrical power from the electric motor, the method comprising the steps of:

sensing actuation of the starter switch to enable operation of the starter and the electric motor;

driving the electric motor and the starter in response to actuation of the starter switch;

sensing main battery voltage and stopping the electric motor when the sensed battery voltage is less than a predetermined voltage;

sensing time of operation of the electric motor and stopping the electric motor when the electric motor operates for a predetermined time;

sensing engine rotational speed and stopping the electric motor when the engine rotational speed exceeds a predetermined rotational speed;

sensing vehicle speed and stopping the electric motor when the vehicle speed exceeds a predetermined vehicle speed; and

sensing the position of the starter switch and stopping the electric motor when the starter switch is off,

wherein the electric motor assists the starter in starting the engine so that life of the starter is increased.

10. The method of claim 9, including the steps of:

sensing voltage of the main battery and preventing operation of the electric motor until a voltage condition of the main battery is sufficient to power the motor without damage to the main battery, and

sensing a clutch condition of a clutch of the vehicle and preventing operation of the electric motor when the clutch is engaged,

wherein only the starter starts the vehicle until the voltage condition and the clutch condition are satisfied.

11. The method of claim 9, including the steps of:

sensing vehicle speed before operation of the electric motor and preventing operation thereof until vehicle speed is zero, and

sensing engine rotational speed before operation of the electric motor and preventing operation thereof until rotational speed is zero.

12. The method of claim 9, wherein the starter and the electric motor are operated simultaneously to start the vehicle.

13. The method of claim 9, including the steps of:

measuring engine load, and

selecting a value from a starting torque map in response to the engine rotational speed and the engine load,

wherein the amount of energization of the electric motor by the main battery depends on the selected value.

14. A vehicle including a starter connected to an internal combustion engine and powered by a sub-battery;

an electric motor directly connected to the engine;

a motor drive control apparatus including a motor controller for controlling a driving function and a power generating function of said electric motor;

a main battery electrically connected to said electric motor for providing power to and receiving electrical power from said electric motor,

circuitry configured to sense a main battery voltage of said main battery, said motor controller enabling operation of said electric motor when the voltage of said main battery is sufficient to drive said motor;

a clutch switch for detecting when a vehicle transmission is in an engaged condition;

an engine rotational speed sensor for discontinuing operation of said electric motor when engine rotational speed is greater than a predetermined engine rotational speed;

a vehicle speed sensor for discontinuing operation of said electric motor when vehicle speed is greater than a predetermined vehicle speed, and

a starter switch sensor for discontinuing operation of said electric motor when said starter switch is turned off,

wherein said motor controller operates said electric motor and said starter when

     1) said starter switch is on,

     2) the main battery voltage exceeds a minimum voltage, and

     3) the transmission is in an engaged condition, said circuitry being configured to discontinue operation of said electric motor when the main battery voltage drops to less than a predetermined voltage.

15. The vehicle of claim 14, including a timer for discontinuing operation of said electric motor when a continuous drive time for said electric motor exceeds a predetermined time.

16. The vehicle of claim 14, wherein said motor drive control apparatus simultaneously drives said starter with said sub-battery and said electric motor with said main battery.