Hybrid Control System

SYSTEM OUTLINE

FEATURES OF TOYOTA HYBRID SYSTEM
This system controls the following modes in order to achieve the most efficient operations to match the driving conditions.
1. Supply of electrical power from the HV battery to motor generator no.2 provides force to drive the wheels.
2. While the tires are driven by the engine via the planetary gears, motor generator no.1 is driven via the planetary gears to supply electricity to motor generator no.2 to drive the wheels.
3. When the vehicle is decelerating, kinetic energy from the wheels is recovered and converted into electrical energy and used to recharge the HA battery by means of motor generator no.2.

The hybrid vehicle control ECU switches between these modes (1, 2, 1+2, or 3) according to the driving conditions. However, when the state of charge of the HA battery is low, the HV battery is charged by the engine by turning motor generator no.1.

CRUISE CONTROL OPERATION
Cruise control is the speed control device, which sets the desired speed by just operating the switch on the control panel without pressing the accelerator pedal. This device is used when you would like to drive the vehicle at the fixed speed.

1. SET CONTROL
If you operate the SET/COAST switch when driving (The available range of set speed: between about 40 and 200 kph) with the main switch is ON (When power indicator comes on), the device memorizes vehicle's speed when switch is off and controls the fixed speed.

2. SET SPEED CONTROL
This device compares the vehicle's running speed and the memorized speed, and controls the driving power of the motor and the engine by calculating the cruise control requirements so that both speed become equivalent.

3. COAST CONTROL
If the SET/COAST switch is continued to be ON during the running with the cruise control, the device recognizes the cruise control requirement is at 0 and decelerates the vehicle's speed. Then the device memorizes the speed when the switch is off in order to control the fixed speed.

In each time you operate SET/COAST switch momentarily (For about 0.5 second), the memorized speed is decreased in about 1.5 kph. However, in case of the tap-down operation with more than 5-kph gap between the memorized speed and vehicle's running speed, the device memorizes the vehicle's speed when the switch is off and controls the fixed speed.

4. ACCEL CONTROL
If the RESUME/ACCEL switch is continued to be ON during the running with the cruise control, the device recognizes the cruise control is on the acceleration side and accelerates the vehicle's speed. Then the running speed when the switch is off is memorized to control the fixed speed.

In each time you operate RESUME/ACCEL switch momentarily (For about 0.5 second), the memorized speed is increased in about 1.5 kph. However, if there is more than 5-kph gap between the memorized speed and vehicle's running speed, this operation does not change the memorized speed. (Tap-up operation is not available.)

5. RESUME CONTROL
If the running speed is faster than the low speed limit afier the cruise control is canceled manually, the fixed speed is controlled by the OFF-ON operation of RESUME/ACCEL switch, so that the vehicle's speed returns to the memorized speed at the time the cruise control is released.

6. MANUAL CANCEL CONTROL
When each of the following signals is input during driving with cruise control, the cruise control is released with turning the cruise control requirement to 0. (The memorized speed is maintained when following signals except the signal, main switch OFF is input.)
- Stop light switch ON (Pressing the brake pedal)
- Control switch's cancel switch ON
- Main switch OFF

7. AUTO CANCEL FUNCTION
A. The memorized speed is erased and the control is canceled if the following conditions occur. The power indicator blinks at that time until the main switch is turned ON. The speed control is unavailable unless the main switch is turned ON again.
- When the stop light switch breaks or short-circuits.
- When sudden change of the running speed signal occur.
B. The memorized speed is erased and the control is canceled if the following conditions occur.
- When the malfunction of the stop light switch input circuit occurs.
- When the running speed becomes slower than 40km/h.
- When the running speed becomes slower than the speed that 16 kph subtracted from the memorized speed.

8. REGENERATIVE SYSTEM OPERATION
This system operates the motor as a generator to change the kinetic energy of the vehicle into the electricity when accel pedal release or foot braking controls the vehicle, and store the electricity in the battery.