Browse Prior Art Database

METHOD FOR AUTOMATIC DOWNSHIFTING OF TRANSMISSION ON HILL DESCENT

IP.com Disclosure Number: IPCOM000243432D
Publication Date: 2015-Sep-21
Document File: 1 page(s) / 195K

Publishing Venue

The IP.com Prior Art Database

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 71% of the total text.

Page 01 of 1

METHOD FOR AUTOMATIC DOWNSHIFTING OF TRANSMISSION ON HILL DESCENT

Brake calipers typically engage and disengage to stop the vehicle motion. When a brake caliper becomes hot from over-usage, it may result in undesirable issues such as reduced braking function. Specifically, during a downhill drive, if a driver applies the brakes for a long period, the brake pads may overheat. This heat is transferred to the brake oil which in turn heats up, expands and results in the degradation of the critical braking function. When brake fluid heats up, the customer may sense this event as a brake pedal feeling that is "spongy". Additionally, the brake pads wear out more quickly. Customers may also experience a burnt smell from hot brakes. A preferred action when descending a steep hill is to utilize engine braking, i.e., shift the transmission into a lower gear (downshift) in order to allow the engine to absorb some of the momentum from the kinetic energy of the moving vehicle. Some customers do not know about this proper engine braking action. Furthermore, in future autonomous cars, there is no driver to perform the manual downshift.

Method

This method performs automatic downshifts when vehicle approaches a hill. A hill descend can easily be inferred from an onboard brake pressure (BP) sensor or similar inference method. When BP increases,
i.e., vehicle is going downhill, the transmission is automatically shifted to a lower gear that reduces the vehicle's speed but at same tim...