Anyone had the Pedestrian Detection activate?

Discussion in 'Gen 4 Prius Technical Discussion' started by Jim in NC, Apr 5, 2019.

  1. Jim in NC

    Jim in NC Active Member

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    I've had my my Prius warning for BRAKE! stop me from hitting something in the garage, on secondary roads when I was quickly closing on another vehicle or when someone cut me off on the highway.

    Has anyone experienced the Pedestrian warning alarm? Does it stop the car? Is there a special message?
     
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  2. Elektroingenieur

    Elektroingenieur Senior Member

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    I don’t have any firsthand experience to share, fortunately, but according to New Car Features (more info), in vehicles that have the pedestrian detection function, it can operate any of the three pre-collision functions, depending on the situation:

    (1) Pre-collision warning

    When the system determines that the possibility of a frontal collision is high, a buzzer will sound and a warning message will be displayed on the multi-information display to urge the driver to take evasive action.

    (2) Pre-collision brake assist

    When the system determines that the possibility of a frontal collision is high, the system applies greater braking force in relation to how strongly the brake pedal is depressed.

    (3) Pre-collision braking

    When the system determines that the possibility of a frontal collision is high, the system warns the driver. If the system determines that the possibility of a frontal collision is extremely high, the brakes are automatically applied to help avoid the collision or reduce the collision speed.

    Another section explains, regarding pre-collision braking:

    (2) If the vehicle is stopped by the operation of the pre-collision braking function, the pre-collision braking function operation will be canceled after approximately 2 seconds. Depress the brake pedal as necessary.

    [ . . . ]

    (5) A large amount of braking force is applied while the pre-collision braking function is operating. Additionally, as the vehicle may creep after the pre-collision braking function has operated, the driver should depress the brake pedal as necessary.
    I believe the same message (“BRAKE !” or “ブレーキ!” or whatever) is always used.
     
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  3. alanclarkeau

    alanclarkeau Senior Member

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    I don't have pedestrian warning on mine, but yes, with normal warnings, it's Red and simply says BRAKE!, which fills the screen (from memory white print, red background).

    It primes the brakes, as you mentioned "(5) A large amount of braking force is applied while the pre-collision braking function is operating." At that stage, you only barely have to touch the brake pedal, and it applies full braking - a bit off-putting the first time, but I'm prepared for it now.

    It's like this (except the wheel is on the wrong side in this drawing)
    upload_2019-4-6_13-57-17.png
     
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  4. alanclarkeau

    alanclarkeau Senior Member

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    I've got a commute every Friday night where it will often catch me out twice within a kilometer, same road.

    First is a bend in the road, and if there's a car parked at a certain spot, the AEB thinks I'm going to hit it because it's at that stage directly in front of me [note that we drive on the LH side of the road]:
    upload_2019-4-6_14-44-22.png

    then only a couple of bends later, is this situation - not as often, possibly because there is a white line on the left of the road, but in the rain, it tends not to see white lines as well - maybe could just be the angle different - this is going uphill, the other is on a downhill slope:

    upload_2019-4-6_14-45-6.png

    If there's no traffic coming, I bear toward or straddle the centre-line which avoids it.
     
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  5. kithmo

    kithmo Couch Potato

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    It takes into account the speed you're going and also the steering angle, so in that scenario Alan I would think that if you approach more to the left then steer to the right before you get close enough to activate the warning it will not appear.
     
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  6. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Third gen with radar cruise tension the seat belts IIRC. And maybe does something with the headrests??
     
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  7. kithmo

    kithmo Couch Potato

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    I don't have the pedestrian warning sound and I thought I didn't have the pedestrian collision detection, but I did get the "BRAKE" warning when a guy stepped out in front of me in a car park.
     
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  8. ice9

    ice9 Active Member

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    I had one incident which activated the pre-collision braking system when I inadvertently went through a red light. I know it engaged because crossing-traffic had already stopped, and I had already steered clear to avoid a collision. That's when the brakes automatically engaged and brought me to a dead stop in the middle of the intersection (despite my attempt to proceed through it). I don't recall any pre-collision warning or buzzer, but under those circumstances I probably wouldn't have noticed the alarms since at the time I was 100% focused on avoiding a collision.

    I had mixed feeling about this (both annoyed and impressed at the same time). Although my experience pointed to a possible safety issue with the system (involuntary stopping in the middle of a busy intersection), I decided that the benefits probably outweighed the hazards. Had the lead car, crossing from my right, failed to stop, without the pre-collision breaking system there would surely have been an accident. WITH the pre-collision breaking system, the collision would have been avoided (had the other driver failed to stop) but, as it did, it would have left my vehicle exposed to crossing traffic coming from the left.
     
  9. 360texas

    360texas Member

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    Yes, when backing out of grocery store diagonal parking... I got repeating BEEP's ... while in reverse .... when another car about 20 feet away started to cross my backing path. Same thing occurred when a pedestrian about 5 feet away entered my back up path.

    Regarding the RED/white BREAK sign when slowly entering my garage and car front was slowly approaching an empty card board box (read object). Yes I forced the 'pre collision' to engaged just to experience the braking affect. IT WORKS
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    None of those things you described were PCS (Pre-Collision).

    The rear beeps are part of the Rear Cross traffic Alert which uses radars mounted behind the rear bumper. (The dame radars are used for the Blind Spot Monitoring System).

    The garage scenario is the Intelligent Clearance Sonar (ICS) that were activated. There are 12 sonar parking sensors around the car. Those deal with low speed such as the garage scenario.
     
  11. alanclarkeau

    alanclarkeau Senior Member

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    As @Tideland Prius said, it wasn't PCS. The Pre-Collision Braking or Warning only work at over 7mph (10km/hr).
    I suspect the sign said:
    upload_2019-7-3_10-9-36.png

    not BREAK. It's Lane Departure warning which advises, more gently, to have a BREAK:
    upload_2019-7-3_10-11-17.png
     
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