System Description [07/2015 - ]

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 button).
• Operation of constant speed control mode is the same as that for a conventional cruise control system. Refer to SYSTEM DESCRIPTION [07/2015 - ]

1. 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 and motor drive force to decelerate the vehicle. If further deceleration is required, the system controls the brake booster with master cylinder assembly 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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).
   Fig 1: Identifying Cruise Control Modes

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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.

1. Low speed limit

   The lowest possible set speed is approximately 50 km/h (or 30 mph). The dynamic radar cruise control system cannot be set when the vehicle speed is below the low speed limit. Control of vehicle speed will be automatically canceled but the stored vehicle speed will be retained when the vehicle speed drops below the low speed limit while the dynamic radar cruise control system is controlling vehicle speed.

2. High speed limit

   The highest possible set speed is approximately 180 km/h (or 110 mph). The dynamic radar cruise control system will be set at the high speed limit when the cruise control is set and the vehicle speed is over the high speed limit. Also, +/RES cannot be used to increase the speed beyond the high speed limit.

Fig 2: Identifying Cruise Control Indicator

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The cruise control main switch is used to turn the dynamic radar cruise control system on and off, as well as operate 7 functions: SET, - (COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP and CANCEL. The SET, TAP-DOWN, and - (COAST) functions, and the RES (RESUME), TAP-UP, and + (ACCEL) functions are operated with the same switch. The cruise control main switch is an automatic return type switch which turns on only while operating it in the direction of each arrow and turns off after releasing it.

HINT: 

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 button). (The cruise control indicator and "RADAR READY" indicator come on.)

1. MODE CONTROL

   Push and hold the switch of the cruise control main switch (ON/OFF button) for 1.5 seconds or more with the dynamic radar cruise control system off to change to the constant speed control mode.

2. SET CONTROL

   The vehicle speed is stored and vehicle-to-vehicle distance control mode begins controlling vehicle speed when the cruise control main switch is pushed to -/SET while driving with the dynamic radar cruise control system on, and the vehicle speed is over the low speed limit. The cruise control SET indicator will display, and the set speed will be displayed in the multi-information display.

   Fig 3: Identifying Cruise Control And Cruise Control SET Indicators

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   TEXT IN ILLUSTRATION
   
   

   *1	Cruise Control Indicator
   *2	Cruise Control SET Indicator

3. - (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 1 km/h (or 1 mph)*1 or 5 km/h (or 5 mph)*2.

   • *1: for Speedometer with Imperial Units for Main Scale
   • *2: for Speedometer with Metric Units for Main Scale
4. TAP-DOWN CONTROL

   When vehicle-to-vehicle distance control mode is controlling vehicle speed and the cruise control main switch is tapped to the -/SET side (for 0.6 seconds or less), the stored vehicle speed decreases by approximately 1 km/h (or 1 mph) for each time the switch is tapped.

5. + (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 1 km/h (or 1 mph)*1 or 5 km/h (or 5 mph)*2. Pushing the cruise control main switch to +/RES while following a vehicle using vehicle-to-vehicle distance control mode does not increase actual vehicle speed, but changes only the set speed.

   • *1: for Speedometer with Imperial Units for Main Scale
   • *2: for Speedometer with Metric Units for Main Scale
6. 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) for each time the switch is tapped.

7. MANUAL CANCEL CONTROL

   Performing any of the following cancels dynamic radar cruise control system control of vehicle speed (the stored vehicle speed in the hybrid vehicle control ECU assembly is maintained).

   • Depressing the brake pedal.
   • Moving the shift lever from D or S to any other position.
   • Selecting the 3rd, 2nd, or 1st range with the shift lever in S.
   • Pulling the cruise control main switch to CANCEL.
   • Turning the dynamic radar cruise control system off using the cruise control main switch (ON/OFF button) (The stored vehicle speed in the hybrid vehicle control ECU assembly is not maintained.).
8. RES (RESUME) CONTROL

   If control of vehicle speed by the dynamic radar cruise control system was canceled due to any of the manual cancel conditions (other than turning the dynamic radar cruise control system off using the ON/OFF switch), and if vehicle speed is more than approximately 40 km/h (or 25 mph), pushing the cruise control main switch to +/RES restores and maintains the stored vehicle speed from the time of cancellation.

The driving support ECU assembly determines the distance to the vehicle in front, relative speed, target speed reduction, and deceleration rate. Based on this data, the hybrid vehicle control ECU assembly transmits a brake demand signal to the skid control ECU.

This system has an automatic cancellation function (fail-safe). Refer to FAIL-SAFE CHART [07/2015 - ]