eEMOTIV
20-04-2009, 02:19 PM
Original post by DavesZ#3 on http://my350z.com
Full thread http://my350z.com/forum/2003-2008-nissan-350z/251136-tcs-vdc-difference.html#post7226480
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VDC Function
In addition to the TCS/ABS function, the driver steering amount and brake operation amount are detected from the steering angle sensor and pressure sensor, and the vehicle's driving status (amount of understeering / over-steering) is determined from information from the yaw rate sensor/side G sensor, wheel sensor, etc., and this information is used to improve vehicle stability by controlling the braking and engine power to all four wheels.
The SLIP indicator lamp flashes to inform the driver of VDC operation.
During VDC operation, the body and brake pedal lightly vibrate and mechanical noises may be heard. This is normal.
The ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp might turn on when the vehicle is subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the engine is running. In this case, restart the engine on a normal road, and if the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off, there is no problem.
TCS Function
The wheel spin of the drive wheels is detected by the VDC/TCS/ABS control unit from the wheel speed signals from the four wheels, so if wheel spin occurs, the rear wheel right and left brake fluid pressure
control and engine fuel cut are conducted while the throttle value is restricted to reduce the engine torque and decrease the amount of wheel spin. In addition, the degree the throttle is opened is controlled to
achieve the optimum engine torque.
Depending on road circumstances, the driver may have a sluggish feel. This is normal, because the optimum traction has the highest priority under TCS operation.
TCS may be activated any time the vehicle suddenly accelerates, suddenly downshifts, or is driven on a road with a varying surface friction coefficient.
During TCS operation, it informs a driver of system operation by flashing SLIP indicator lamp.
__________________
Reply posted by eEMOTIV
G'day everyone,
Pardon the late reply but we were told about this thread and suggested that we might like to contribute.
There’s an element to the VDC’s operation that probably needs to be added to this and that is the issue of ideal vehicle path relative to actual. All ESP, DSC and VDC systems work by comparing the actual vehicle behaviour against a model of the manufacturers “ideal” and that is certainly true with the 350Z system which is based on the Bosch ESP technology. This is important to understand because by “ideal” we’re talking about the manufacturers view and not some sort of objective handling truth “ideal”.
With oversteer being the scariest outcome for car companies , the engineers need to make sure that even a sporty car has strict limits to what it can do dynamically and these are often set by the marketing department. That can be both a good and bad thing because the same chassis or vehicle released by 2 different brands will have a different dynamic personality set by the VDC (ESP or DSC) system. A real world example would be the G35 vs the 350Z. Similar chassis though the G35 is longer however the yaw and slip tolerances in the G35 are very different to the 350Z. That is, Nissan allows more aggressive (riskier to the driver) behaviour in the 350Z via the VDC and TCS algorithm than the G35 which is meant to be an executive sedan but with a sportier feel.
DavesZ#3, the other aspect I’d add to the summary is that TCS plays a big part in handling and cornering in the area of throttle steer and the VDC/TCS do work in tandem. There’s overlap in their function and implementation, more about that here http://my350z.com/forum/7226344-post23.html
Anyway, hope that helps the discussion, please feel free to ask us any further questions on the system as we’ve been playing with it for some time.
Best
Ed
ed@eemtoiv.com
www.eEMOTIV.com
__________________
eEMOTIV.com
Full thread http://my350z.com/forum/2003-2008-nissan-350z/251136-tcs-vdc-difference.html#post7226480
-------------------------------------------------
VDC Function
In addition to the TCS/ABS function, the driver steering amount and brake operation amount are detected from the steering angle sensor and pressure sensor, and the vehicle's driving status (amount of understeering / over-steering) is determined from information from the yaw rate sensor/side G sensor, wheel sensor, etc., and this information is used to improve vehicle stability by controlling the braking and engine power to all four wheels.
The SLIP indicator lamp flashes to inform the driver of VDC operation.
During VDC operation, the body and brake pedal lightly vibrate and mechanical noises may be heard. This is normal.
The ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp might turn on when the vehicle is subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the engine is running. In this case, restart the engine on a normal road, and if the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off, there is no problem.
TCS Function
The wheel spin of the drive wheels is detected by the VDC/TCS/ABS control unit from the wheel speed signals from the four wheels, so if wheel spin occurs, the rear wheel right and left brake fluid pressure
control and engine fuel cut are conducted while the throttle value is restricted to reduce the engine torque and decrease the amount of wheel spin. In addition, the degree the throttle is opened is controlled to
achieve the optimum engine torque.
Depending on road circumstances, the driver may have a sluggish feel. This is normal, because the optimum traction has the highest priority under TCS operation.
TCS may be activated any time the vehicle suddenly accelerates, suddenly downshifts, or is driven on a road with a varying surface friction coefficient.
During TCS operation, it informs a driver of system operation by flashing SLIP indicator lamp.
__________________
Reply posted by eEMOTIV
G'day everyone,
Pardon the late reply but we were told about this thread and suggested that we might like to contribute.
There’s an element to the VDC’s operation that probably needs to be added to this and that is the issue of ideal vehicle path relative to actual. All ESP, DSC and VDC systems work by comparing the actual vehicle behaviour against a model of the manufacturers “ideal” and that is certainly true with the 350Z system which is based on the Bosch ESP technology. This is important to understand because by “ideal” we’re talking about the manufacturers view and not some sort of objective handling truth “ideal”.
With oversteer being the scariest outcome for car companies , the engineers need to make sure that even a sporty car has strict limits to what it can do dynamically and these are often set by the marketing department. That can be both a good and bad thing because the same chassis or vehicle released by 2 different brands will have a different dynamic personality set by the VDC (ESP or DSC) system. A real world example would be the G35 vs the 350Z. Similar chassis though the G35 is longer however the yaw and slip tolerances in the G35 are very different to the 350Z. That is, Nissan allows more aggressive (riskier to the driver) behaviour in the 350Z via the VDC and TCS algorithm than the G35 which is meant to be an executive sedan but with a sportier feel.
DavesZ#3, the other aspect I’d add to the summary is that TCS plays a big part in handling and cornering in the area of throttle steer and the VDC/TCS do work in tandem. There’s overlap in their function and implementation, more about that here http://my350z.com/forum/7226344-post23.html
Anyway, hope that helps the discussion, please feel free to ask us any further questions on the system as we’ve been playing with it for some time.
Best
Ed
ed@eemtoiv.com
www.eEMOTIV.com
__________________
eEMOTIV.com