Drowsy Driver Detection: Notes
DESCRIPTION
| 1. | Refer to ADAPTIVE CRUISE CONTROL (ACC) RADAR - Can also be referred to as the Driver Assistance System Module (DASM). |
| 2. | Refer to INSTRUMENT PANEL CLUSTER (IPC) . |
| 3. | Refer to BODY CONTROL MODULE (BCM) . |
Drowsy Driver Detection (DDD) is a driver assistance system designed to detect when a driver is getting drowsy which could potentially affect their ability to operate a motor vehicle. The system is also capable of alerting the driver when the possibility of the driver falling asleep increases. The DDD system monitors steering wheel inputs (micro steering) to determine drowsiness. When drowsiness is detected, the DDD system will request an audible and visual warning to alert the driver.
OPERATION
The DDD system is set to be available when the following conditions are met:
- No DDD system faults are present
- Vehicle speed does not exceed 200 km/h (124 mph)
When criteria is met the ACC radar transmits a Controller Area Network (CAN) message indicating that the system is actively monitoring for DDD.
Once the DDD system is available, the ACC Radar monitors the steering wheel inputs to create a range of acceptable tolerances. Those inputs are:
- Counterclockwise positive angle
- Steering speed value
The ACC radar also receives the following signals as part of the DDD algorithm:
- Accelerator pedal position
- Brake pedal status, brake and driver brake pedal torque signals
- External lights and headlamp switch signals (i.e hazard, fog, switch positions)
- Turn signal indicators
- Steering wheel switch commands
- Engine speed signals
- Engine status signal
- Cruise control (normal or adaptive) state
- Wheel speed
- Active Lane Management (ALM) steering control request
- Steering column torque signal
Other inputs used:
- ALM information from the camera to detect lane crossing
- Detection of a jerk in the steering wheel movement that is outside of the tolerance band that has been mapped by the DDD system at the beginning of the ignition cycle
When using the signals and systems to determine the DDD algorithm, when there is a suspected instance of a drowsy driver the DDD system will trigger an alert. The alert will be a visual and an audible alert. The ACC radar is in control of the activation and deactivation of these warnings by transmitting a signal to alert the driver. This signal will be continuously transmitted until the ACC radar receives signal from the steering wheel switch command. This command is initiated by the customer selected "OK" on the hard switch. The IPC will then activate a drowsiness detected stored message.
Whenever there is a fault detected in any of the systems and inputs used by the DDD algorithm, the ACC radar will disable the DDD system, set a Diagnostic Trouble Code (DTC) and then alert the driver that the system is not available via a message on the IPC.