Engine Hybrid System. Land Cruiser. Urj200, 202 Grj200 Vdj200
Cruise Control. Land Cruiser. Urj200, 202 Grj200 Vdj200
Dynamic Radar Cruise Control System -- System Description |
| GENERAL |
- HINT:
- The dynamic radar cruise control system has two cruise control modes: constant speed control mode and vehicle-to-vehicle distance control mode
- Vehicle-to-vehicle distance control mode is selected by default when the dynamic radar cruise control system is turned on using the cruise control main switch (ON/OFF).
- Operation of constant speed control mode is the same as that for a conventional cruise control system.
This system maintains the vehicle at the speed that the driver has set, as long as there are no vehicles ahead. In addition to this, the system maintains the vehicle-to-vehicle distance that has been set by the driver. If the system detects a vehicle driving at a slower speed ahead while the driver is driving at a constant speed, it controls the engine to decelerate the vehicle. If further deceleration is required, the system controls the hydraulic brake booster in order to apply the brakes. Thereafter, if there are no vehicles ahead within the set vehicle-to-vehicle distance because either the vehicle ahead or the driver has changed lanes, the system accelerates slowly to reach the set speed and resumes driving at this speed.
Vehicle-to-vehicle distance control mode is designed to control vehicle speed and vehicle-to-vehicle distance using the constant speed function, deceleration cruising function, follow-up cruising function, and acceleration cruising function.
The millimeter wave radar sensor assembly and driving support ECU assembly control the system while vehicle-to-vehicle distance control mode is operating, and send signals to each actuator and ECU.
In vehicle-to-vehicle distance control mode, the dynamic radar cruise control system receives signals from the forward recognition camera, yaw rate sensor (airbag sensor assembly) and the steering sensor. Based on these signals, the system then estimates curve radius and compensates for information on the preceding vehicle while turning. It can also compensate using brake control when approaching another vehicle.
This system judges the presence of a vehicle in front and the distance to it based on the signals from the millimeter wave radar sensor assembly while vehicle-to-vehicle distance control mode is operating. Using this information, the system informs the driver of danger with the warning buzzer, performs brake control, and turns on the stop lights when approaching a vehicle in front.
The following illustration shows a control example under the following conditions: own vehicle speed is 100 km/h (62 mph) and the speed of the vehicle in front is 80 km/h (50 mph). The vehicle distance can be set to any of the following 3 distances by operating the vehicle-to-vehicle distance control switch: long (approximately 50 m (or 160 ft.)), middle (approximately 40 m (or 130 ft.)), and short (approximately 30 m (or 100 ft.)) when the vehicle speed is approximately 80 km/h (50 mph).
- HINT:
- Vehicle distance increases and decreases in accordance with vehicle speed.
- Control conditions are indicated on the multi-information display in the combination meter assembly.
| FUNCTION OF MAIN COMPONENTS |
| Item | Outline |
| Cruise Control Indicator (Multi-information Display in the Combination Meter Assembly) |
|
| Warning Buzzer (Combination Meter Assembly) | If the ECM or driving support ECU assembly detects an automatic cancel signal while the dynamic radar cruise control system is controlling vehicle speed, this buzzer sounds only once to inform the driver. |
| Cruise Control SET Indicator (Multi-information Display in the Combination Meter Assembly) | The ECM displays the cruise control SET indicator in the multi-information display when constant speed control is started by pushing the cruise control main switch to -/SET. |
| Multi-information Display (Combination Meter Assembly) |
|
| Cruise Control Main Switch (ON/OFF) |
|
| Cruise Control Main Switch (Control Switch) | Vehicle speed setting, deceleration, preset speed resumption, acceleration, and cancel request signals are sent to the ECM through the operation of this switch. |
| Vehicle-to-vehicle Distance Control Switch (Steering Pad Switch Assembly) | While the system is in vehicle-to-vehicle distance control mode, the driver can operate the vehicle-to-vehicle distance control switch to select the vehicle-to-vehicle distance in three stages: long, middle, and short. |
| Stop Light Switch Assembly | Detects the depression of the brake pedal and transmits signals to the ECM. |
| Millimeter Wave Radar Sensor Assembly | Radiates radar waves forward, uses the reflected waves for detecting the presence of a vehicle in front, vehicle-to-vehicle distance, and relative speed, and transmits this information to the driving support ECU assembly. |
| Steering Angle Sensor | Detects the angle and direction of steering and transmits signals to the driving support ECU assembly. |
| Speed Sensor | A vehicle speed signal which is output from the skid control ECU is sent to the ECM. |
| Yaw Rate Sensor (Airbag Sensor Assembly) | Detects the yaw rate of the vehicle and transmits signals to the driving support ECU assembly. |
| Skid Control ECU (Master Cylinder Solenoid) |
|
| pre-crash safety city buzzer | Sounds upon receiving signals from the driving support ECU assembly. |
| ECM |
|
| TCM*1 | Controls the transmission in accordance with the signal from the ECM. |
| Throttle with Motor Body Assembly | Upon receiving signals from the ECM, the throttle control motor actuates the throttle valve. |
| Driving Support ECU Assembly | While the dynamic radar cruise control system is in vehicle-to-vehicle distance control mode, the driving support ECU assembly detects vehicles in front based on signals from the millimeter wave radar sensor assembly. Then, the driving support ECU assembly calculates the acceleration or deceleration required in order to attain the target vehicle-to-vehicle distance, and outputs request signals to the ECM. |
| Forward Recognition Camera | Captures the image in front of the vehicle to detect lane markers and objects on the road ahead. |
- *1: for 3UR-FE
| OPERATION OF DYNAMIC RADAR CRUISE CONTROL |
Constant Speed Control Mode:
Function Outline Set Control - The vehicle speed is stored and control of vehicle speed begins when the cruise control main switch is pushed to -/SET while driving at a speed of between approximately 50 km/h (30 mph) and 180 km/h (110 mph) with the dynamic radar cruise control system on.
- When the set speed is stored, the cruise control SET indicator illuminates and the set speed is displayed on the multi-information display.
Low Speed Limit Control The low speed limit is approximately 40 km/h. If the vehicle speed drops below the low speed limit, speed control by the dynamic radar cruise control system is canceled automatically and the set vehicle speed is kept in memory. High Speed Limit Control The highest possible set speed is approximately 180 km/h (110 mph). The dynamic radar cruise control system cannot be set when the vehicle speed is over the high speed limit. Also, + (ACCEL)/RES (RESUME) cannot be used to increase the speed beyond the high speed limit. + (ACCEL) Control When the dynamic radar cruise control system is controlling vehicle speed and the cruise control main switch is pushed to +/RES and held in that position, the dynamic radar cruise control system sends a signal to the ECM to operate the throttle valve motor of the throttle body with motor assembly to open the throttle valve. Following this, the vehicle speed is stored and maintained when the cruise control main switch is released. If the vehicle speed exceeds the high speed limit (approximately 200 km/h (125 mph)) while the cruise control main switch is in the +/RES position, the highest possible set speed is stored. Tap-up Control When the dynamic radar cruise control system is controlling vehicle speed and the cruise control main switch is tapped to +/RES (for approximately 0.6 seconds), the stored vehicle speed increases by approximately 1 km/h or 1 mph for each time the switch is tapped. When the cruise control main switch is tapped to +/RES and the difference between the current and stored vehicle speed is more than 5 km/h (3 mph), the stored vehicle speed will not be changed. - (COAST) Control When the dynamic radar cruise control system is controlling vehicle speed and the cruise control main switch is pushed to -SET and held in that position, the cruise control system sends a "throttle valve opening angle 0°" demand signal to the ECM. Following this, the vehicle speed is stored and maintained when the cruise control main switch is released. - HINT:
- An actual throttle valve opening angle of 0° is not possible due to factors such as idle speed control.
TAP-DOWN Control When the dynamic radar cruise control system is controlling vehicle speed and the cruise control main switch is tapped to -SET (for approximately 0.6 seconds), the stored vehicle speed decreases by approximately 1 km/h or 1 mph for each time the switch is tapped. When the cruise control main switch is tapped to -SET and the difference between the current and stored vehicle speed is more than 5 km/h (3 mph), the current vehicle speed is stored and speed control is performed. Auto Cancel Control This system has an automatic cancellation function (fail-safe). Manual Cancel Control Performing any of the following cancels dynamic radar cruise control system control of vehicle speed (the stored vehicle speed in the ECM is maintained). - Depressing the brake pedal.
- Moving the shift lever to any position except D or S (6th, 5th or 4th gear).
- Pulling the cruise control main switch to CANCEL.
- Turning the cruise control main switch off (the stored vehicle speed in the ECM is not maintained).
RES (Resume) Control After a control cancellation operation is performed by cancel control which stores the vehicle speed, the set vehicle speed at the time of the control cancellation operation can be resumed by driving the vehicle at a speed between approximately 50 km/h and the high speed limit and turning the +/RES switch on. Down Shift Control When driving on an uphill with the dynamic radar cruise control system controlling vehicle speed, the transmission may downshift from an overdrive gear. After the downshift, if the system determines that the uphill inclination has become smaller based on the throttle valve opening angle, the transmission automatically returns to the overdrive gear. - The vehicle speed is stored and control of vehicle speed begins when the cruise control main switch is pushed to -/SET while driving at a speed of between approximately 50 km/h (30 mph) and 180 km/h (110 mph) with the dynamic radar cruise control system on.
Vehicle-to-vehicle Distance Control Mode:
Function Outline Set Control - The vehicle speed is stored and control of vehicle speed begins when the cruise control main switch is pushed to -/SET while driving at a speed of between approximately 50 km/h (30 mph) and 180 km/h (110 mph) with the dynamic radar cruise control system on.
- When the set speed is stored, the cruise control SET indicator illuminates and the set speed is displayed on the multi-information display.
Low Speed Limit Control The low speed limit is approximately 40 km/h. If the vehicle speed drops below the low speed limit, speed control by the dynamic radar cruise control system is canceled automatically and the set vehicle speed is kept in memory. High Speed Limit Control The highest possible set speed is approximately 180 km/h (110 mph). The dynamic radar cruise control system cannot be set when the vehicle speed is over the high speed limit. Also, + (ACCEL)/RES (RESUME) cannot be used to increase the speed beyond the high speed limit. Constant Speed Control The driving support ECU assembly compares the actual vehicle speed and the stored vehicle speed. When the vehicle speed is less than the stored vehicle speed, it increases the opening angle of the throttle valve. Follow-up Control The vehicle follows the preceding vehicle while maintaining an appropriate vehicle-to-vehicle distance according to the speed of the preceding vehicle. Mode Control When the cruise control main switch (ON/OFF) is pushed and held for 1.5 seconds or more with the dynamic radar cruise control system off, mode changes to constant speed control mode. + (ACCEL) Control When vehicle-to-vehicle distance control mode is controlling vehicle speed and the cruise control main switch is pushed to +RES and held in that position, the stored vehicle speed increases by approximately 5 km/h or 5 mph. Pushing the cruise control main switch to +RES while following a preceding vehicle using vehicle-to-vehicle distance control mode does not increase actual vehicle speed, but changes only the stored vehicle speed. Tap-up Control When vehicle-to-vehicle distance control mode is controlling vehicle speed and the cruise control main switch is tapped to the +/RES side (for 0.6 seconds or less), the stored vehicle speed increases by approximately 1 km/h (or 1 mph) or 5 km/h (or 5 mph)* for each time the switch is tapped. - (COAST) Control When vehicle-to-vehicle distance control mode is controlling vehicle speed and the cruise control main switch is pushed to -SET and held in that position, the stored vehicle speed decreases by approximately 5 km/h (or 5 mph). TAP-DOWN Control When vehicle-to-vehicle distance control mode is controlling vehicle speed and the cruise control main switch is tapped to -/SET (for 0.6 seconds or less), the stored vehicle speed decreases by approximately 1 km/h (or 1 mph) or 5 km/h (or 5 mph)* for each time the switch is tapped. Auto Cancel Control This system has an automatic cancellation function (fail-safe). Manual Cancel Control Performing any of the following cancels dynamic radar cruise control system control of vehicle speed (the stored vehicle speed in the ECM is maintained). - Depressing the brake pedal.
- Moving the shift lever to any position except D or S (6th, 5th or 4th gear).
- Pulling the cruise control main switch to CANCEL.
- Turning the cruise control main switch off (the stored vehicle speed in the ECM is not maintained).
RES (Resume) Control - After a control cancellation operation is performed by cancel control which stores the vehicle speed, the set vehicle speed at the time of the control cancellation operation can be resumed by driving the vehicle at a speed between approximately 50 km/h and the high speed limit and turning the +/RES switch on.
- If the preceding vehicle moves out of the lane while follow-up control is operating, the vehicle speed is gradually increased to the set vehicle speed. At this time, the vehicle speed can be increased by pushing the cruise control main switch to +/RES.
Down Shift Control When driving on an uphill with the dynamic radar cruise control system controlling vehicle speed, the transmission may downshift from an overdrive gear. After the downshift, if the system determines that the uphill inclination has become smaller based on the throttle valve opening angle, the transmission automatically returns to the overdrive gear. Brake Control When a large amount of deceleration is required while vehicle-to vehicle distance control mode is controlling vehicle speed, the hydraulic brake booster is operated to apply the brakes. The stop lights illuminate at this time. - *: w/o Wireless Door Lock Buzzer Answer Back Function
- The vehicle speed is stored and control of vehicle speed begins when the cruise control main switch is pushed to -/SET while driving at a speed of between approximately 50 km/h (30 mph) and 180 km/h (110 mph) with the dynamic radar cruise control system on.