1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Dynamic Radar Cruise Control Question

Discussion in 'Prius v Technical Discussion' started by Cactus Hybrid, Jan 22, 2012.

  1. Cactus Hybrid

    Cactus Hybrid Member

    Joined:
    Apr 1, 2007
    129
    46
    0
    Location:
    Paradise Valley, Arizona
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I have checked most of the posts on Dynamic Radar Cruise Control (DRCC) but none answer my question clearly.

    Here is the scenario...The vehicle in front has cruise control set at 55 MPH, I have my cruise control set at 75 MPH. As I approach the car in front of me, I feel my Prius slowing down. I'm curious what happens with the brake lights.

    I assume when the friction brakes are used, the brake lights come on as my Prius approaches the car travelling slower..Do the friction brakes remain engaged to keep the distance?

    Also, does my Prius "ride the brakes" to maintain the constant distance between me and the car ahead? Does it pulse the brakes? Does it release and engage, release and engage?

    I'm wondering if I'm driving the drivers behind me crazy or not..

    Thanks

    The link below is a nice video abut the DRCC..

     
    #1 Cactus Hybrid, Jan 22, 2012
    archiveman2977 likes this.
  2. PRPrius

    PRPrius Active Member

    Joined:
    Jul 5, 2004
    327
    198
    2
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Advanced
    1) The brake lights will illuminate if the cruise control engages the friction brakes.
    2) Depending at the approach rate, the Prius may not have to use the brakes at all.
    a) It will reduce engine power
    b) if necessary the car will use regeneration to slow the
    car at a higher rate.
    c) if higher decelearation rate is needed, the car will engage the friction brakes with brake lights.
     
    #2 PRPrius, Jan 22, 2012
    archiveman2977 and Cactus Hybrid like this.
  3. PRPrius

    PRPrius Active Member

    Joined:
    Jul 5, 2004
    327
    198
    2
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Advanced
    As far as riding the brakes, it all deppends on the following distance. The longer the distance, the more the car can use power cuts and regeneration to slow down the car. If you are using the short following distance setting, the car may have to use the friction brakes more often. It also depends on the driver that you are following.
     
    #3 PRPrius, Jan 22, 2012
  4. Cactus Hybrid

    Cactus Hybrid Member

    Joined:
    Apr 1, 2007
    129
    46
    0
    Location:
    Paradise Valley, Arizona
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Thanks for the quick response....
     
    #4 Cactus Hybrid, Jan 22, 2012
  5. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    45,024
    16,242
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Why would the car ride the brakes? Would you ride the brakes following a car at 55mph? The cruise could do exactly what you do - slow the car down (and use the brakes if more reduction in speed is necessary) and then maintain speed with the accelerator pedal (you can feel the accelerator pedal move down as it accelerates).

    What he's saying is that if you use the SHORT distance, the car will have less distance to slow down by letting the accelerator off so it would have to use the brakes to slow you down. With a LONG setting, the car has much more space (as a buffer) and would be more inclined to slow down gradually.
     
    #5 Tideland Prius, Jan 22, 2012
    archiveman2977 likes this.
  6. Pixel91

    Pixel91 New Member

    Joined:
    Jun 16, 2012
    1
    0
    0
    Location:
    Marolles en Hurepoix - Essonne (France)
    Vehicle:
    2008 Prius
    Model:
    II
    I think the question is :
    "Do the brake lights turn on when the car is using regeneration to slow down ?"
    In fact, they do turn on if you press the brake pedal to slow down.
    Not necessarily when the cruise system uses regeneration to slow down.
    If you want to know, just ask a friend to follow you with his car, as you are using the cruise control !
    He can tell you by phone when your brake lights are on.
    Or temporarily connect a 12v buzzer in parallel with your brake lights ! :)
     
    #6 Pixel91, Jun 16, 2012
(You must log in or sign up to post here.)