Collision Avoidance Module: Description and Operation
Description
When reversing, the driver is not easy to find objects in the blind spots and to determine the distance from the object. In order to provide the driver safety and convenience, back warning system will operate upon shifting to "R" Ultrasonic sensor will emit ultrasonic wave rearward and detect the reflected wave. Control unit will calculate distance to the object using the sensor signal input and output buzzer alarm in three steps (first, second and third alarm).
Functional Specification
1. PAS(Parking Assist System) functional specification.
(1) Use the IGN1 Power. (IGN1 ON action)
(2) PAS SYSTEM is enabled when Moving forward is under the condition of PAS switch On and vehicle speed is under 10 KPH and backward is under 15KPH.
(3) Front System is enabled when Gear is putting somewhere except for 'P' range position or Parking Brake is released.
(4) Gear shifted to 'R', Rear PAS System will start.
A. Front System makes Front 4 sensors (FL, FCL, FCR, FR) enabled.
B. Rear System makes the Front 4 sensors (FL, FCL, FCR, FR) and Rear 3 sensors (RR, RC, RL) enabled.
2. System function flow.
(1) Above 1), 2), 3) or 1), 2), 4) conditions, the system will start.
(2) Front System has no initial starting sound when it starts and does an alarm system when it detects the obstacle according to distance.
(3) When Rear System is in operation, initial starting sound is ringing 0.5 second just after R gear is shifted and conducts the alarm system by the distance.
(4) Some of sensors have faults, Front system or Rear system sends a fault alarm sound and displays the sensors on the cluster.
(5) Alarms of obstacle consists of 3 level 1, 2, 3 step and 1, 2 alarm sounds intermittently and 3 alarm sounds continuously But Front System does not have 1 step alarm, and in 2 step alarm it just turns on the INDICATOR in the cluster.
(6) According to alarm level. Cluster controls turning the INDICATOR on that is in it.
(7) PAS System is in operation under the condition of PAS switch ON, and PAS switch will keep its last status when IGN is OFF even.
(8) PAS switch OFF will be released when the Gear is shifted to 'R' automatically. PAS switch is recover to OFF condition If PAS OFF released when applying 'R' Gear.
A. IN PAS switch ON, INDICATOR that is in PAS switch turns on and PAS ECU controls the INDICATOR light.
B. PAS switch Factory initial condition is ON.
PAS alarm method
Obstacle are detected by PAS, It alarms driver through the hearing and visual device.But, PAS ECU transmits alarm data to CLUSTER by LIN communication and cluster starts to show visual alarm through alarm data.
1. PAS alarm sound specification.
In the state of IGN ON, and PAS or RPAS turn active, System will do work as below.
If Front system and Rear system has common operational condition (3.1 reference), MICOM checks every sensor and if it finds no fault, after 500ms sends the initial starting Sound for 300mS (But, initial starting sound works not PPS but only under the RPAS system But, if it finds any defect, it sends fault sound and show fault sensor through INDICATOR.
** In Front system, initial starting sound doesn't work but in case PAS sensors have any fault sends fault sound and shows through INDICATOR under the PAS ON condition.
** Acceptable wave error range ±10%
2. Alarm sound output spec by the distance
** Rear buzzer alarm sound
** Front buzzer alarm sound
NOTE:
1. Acceptable wave error range: ±10%
2. Under 30Cmm area, alarm sound could not work.
3. By the Vehicle moving and target shape, distance alarms could not be in order.
4. Alarm sound comes from CLUSTER and period and alarm lasting time of alarm could be changed.
3. INDICATOR display method.
When the System starts, CLUSTER controls INDICATOR according to alarm data like below.If it finds any obstacle, lights immediately, and doesn't find anything, Front System do nothing but Rear System lights INDICATOR as a nothing alarm for 2 seconds after 'R' gear and turns off (If it senses obstacle and then has no obstacle, it lights INDICATOR as a nothing alarm and turns off)
** PAS(Front, Rear alarm System) INDICATOR Display
** RPAS(Rear Parking Alarm System) INDICATOR Display
NOTE:
It displays the position of detected obstacle.Front sensor has no 1 step alarm display(sensing area under 60Cm)Front system has no alarm sound but only display in 2 step alarm.3 step alarm turns on/off 1 sec cycle(0.5sec ON, 0.5sec OFF)If Front system and Rear system release the operational condition, cluster stops the INDICATOR display and alarm sound immediately.(within 230ms)
** INDICATOR light control
** When alarm is working on and released, or nothing alarm, if system operational condition released, display and alarm sound stop immediately.
** In releasing alarm condition, INDICATOR lights turns off within 230ms.
4. PAS ECU and CLUSTER alarm data process.
Cluster response the alarm data from PAS ECU and lights INDICATOR. If it needs alarm delay or INDICATOR light delay, it controls the alarm data as below.
** But recognize R Gear starting point from the initial sound data that comes from PAS ECU.
5. Self diagnosis and fault alarm specification.
System starts to fault alarm when it finds PAS sensor fault.
PAS Sensor fault type is as below.
A. Sensors fault.
B. Sensor signal line OPEN of SHORT to GROUND Error diagnosis is performed by the error time and error type.
Error diagnosis is performed by the error time and error type.
1) Fault diagnosis by the fault time.
A. On System starting -> Display the INDICATOR after inform the fault sensor through the alarm sound(sensor circuit open or GROUND SHORT).
B. On the normal operation, fault occurs (including the fault releasing and normal operation) -> No fault alarm, just INDICATOR show the fault sensor.
2) Fault diagnosis by Fault type.
A. Sensor fault (sensor circuit fault or sensor cell breakdown)-> INDICATOR displays that fault.
B. Sensor WIRE fault (OPEN or GROUND SHORT)-> INDICATOR displays that fault.
C. Sensor drive device of ECU fault-> INDICATOR display as if the sensor has a fault.
6. Sensor fault alarm sound output specification.
In system initial starting, if it has fault sensor, it sounds as below.
** Acceptable wave error range: ±10%
** After sensor fault alarm sound are sent, the other sensors work normally.
** There is no fault alarm when the fault occurs during working normally.
** Alarm sound comes from CLUSTER and period and alarm lasting time of alarm could be changed (If it has any changes, cluster firm must notify Body Control Design team and Chassis Safety control team and MOBIS of changes)
7. Sensor fault display method.
Indicator lights only Fault sensor and when the sensor fault is released, faulty display will be disappeared.But, it is supposed to display the fault when it occurs on the work.