CONTROL DEVICE FOR USE IN VEHICLE, ADAPTED TO CONTROL SAFETY MEASURES AGAINST ELECTRIC POWER SUPPLY FAILURE

• US 20130060412A1
• Filed: 04/20/2011
• Published: 03/07/2013
• Est. Priority Date: 05/17/2010
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Nakagawara, Hidemitsu, Nabeshima, Hisahiro
• Granted Patent: US 8,880,260 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60T 1/005 by locking of wheel or transmission rotation
• CPC Class Codes: B60T 1/062 acting on transmission parts
• CPC Class Codes: B60T 13/746 and mechanical transmission of the braking action
• CPC Class Codes: B60T 17/221 Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M
• CPC Class Codes: B60T 2270/414 Power supply failure
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: F16H 2061/1292 the failing part is the power supply, e.g. the electric power supply
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: F16H 63/3458 with electric actuating means, e.g. shift by wire

Abstract

A vehicular power supply failure time safety measures control apparatus for a vehicle equipped with an electric park lock mechanism includes a means to detect a power supply failure in a park lock power supply, and a means to examine an electric storage state of the park lock power supply after the time of the power supply failure. The control apparatus further includes a park lock means to lock rotation of the wheel by operating the park lock mechanism when the electric storage state of the park lock power supply approaches a lower limit of the electric storage state ensuring the operation of the park lock mechanism.

Claims

1. A vehicular power supply failure time safety measures control apparatus for a vehicle equipped with an electric park lock mechanism to lock rotation of a wheel, the power supply failure time safety measures control apparatus comprising:

a power supply failure detecting means to detect occurrence of one of charge inability and charge malfunction in a park lock power supply of the park lock mechanism;

an electric storage state examining means to examine an electric storage state of the park lock power supply on and after a time of detection of the power supply failure by the power supply failure detecting means; and

a park lock means to lock rotation of the wheel by operating the park lock mechanism, under a vehicle speed condition allowing rotation lock of the wheel with the park lock mechanism, when the electric storage state of the park lock power supply judged by the electric storage state examining means approaches a lower limit of the electric storage state ensuring operation of the park lock mechanism.

2. The vehicular power supply failure time safety measures control apparatus as claimed in claim 1:

wherein the vehicle is an electrically powered vehicle using an electric motor driven with electric power from a higher voltage power supply as at least part of a power source to move the vehicle, and using, as the park lock power supply, a lower voltage power supply charged with the electric power from the higher voltage power supply; and

wherein the power supply failure detecting means is configured to detect one of a failure in the higher voltage power supply, a failure in the lower voltage power supply, and a failure of a charging control system provided between the higher voltage power supply and the lower voltage power supply, for the lower voltage power supply, and thereby to detect the occurrence of the power supply failure including one of the charge inability and the charge malfunction in the park lock power supply.

3. The vehicular power supply failure time safety measures control apparatus as claimed in claim 1, wherein the electric storage state examining means is configured to examine the electric storage state of the park lock power supply by monitoring a voltage of the park lock power supply.

4. The vehicular power supply failure time safety measures control apparatus as claimed in claim 1, wherein the electric storage state examining means is configured to measure an elapsed time from a time of the detection of the power supply failure by the power supply failure detecting means, and to judge the electric storage state of the park lock power supply from the elapsed time.

5. The vehicular power supply failure time safety measures control apparatus as claimed in claim 1:

wherein the vehicle is arranged to use the electric power from the park lock power supply to assist a braking force; and

wherein the vehicular power supply failure time safety measures control apparatus further comprises a vehicle speed limiting means to limit a vehicle speed to prevent the vehicle speed from being increased beyond an upper limit speed by a driving force control of the wheel while the electric storage state of the park lock power supply judged by the electric storage state examining means is in a region capable of stopping the vehicle with a regular assistance for the braking force.

6. The vehicular power supply failure time safety measures control apparatus as claimed in claim 5, wherein the vehicle speed limiting means is configured to set the upper limit speed to a vehicle speed value capable of stopping the vehicle with the regular assistance for the braking force even in the above-mentioned electric storage state, in accordance with the electric storage state of the park lock power supply judged by the electric storage state examining means.

7. The vehicular power supply failure time safety measures control apparatus as claimed in claim 5, wherein the vehicular power supply failure time safety measures control apparatus further comprises a stop warning means to produce a warning to indicate a stop of the vehicle while the electric storage state of the park lock power supply judged by the electric storage state examining means is in the region capable of stopping the vehicle with the regular assistance for the braking force.

8. The vehicular power supply failure time safety measures control apparatus as claimed in claim 1, wherein the vehicle is arranged to use the electric power from the park lock power supply to assist a braking force;

and

wherein the vehicular power supply failure time safe measures control apparatus further comprises a driving force cutting means to reduce a driving force of the wheel to zero after the electric storage state of the park lock power supply judged by the electric storage state examining means enters a region incapable of stopping the vehicle with a regular assistance for the braking force.

9. The vehicular power supply failure time safety measures control apparatus as claimed in claim 8, wherein the vehicular power supply failure time safety measures apparatus further comprises a park warning means to indicate stoppage of the vehicle and application of a parking brake after the electric storage state of the park lock power supply judged by the electric storage state examining means enters the region incapable of stopping the vehicle with the regular assistance for the braking force.