Speed limiter

• US 9,085,237 B2
• Filed: 10/03/2011
• Issued: 07/21/2015
• Est. Priority Date: 10/03/2011
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Kii, Yuji, Maruyama, Tasuku, Matsuura, Munenori
• Primary Examiner(s): Moulis, Thomas
• Application Number:
  US13/200,823
• Publication Number:
  US 20130085655A1
• Time in Patent Office: 1,387 Days
• Field of Search: 701/70, 701/93, 701/94, 701/96, 701/102, 701/110, 701/115, 123/349, 123/350, 123/351, 123/361, 123/399
• US Class Current: 1/1
• CPC Class Codes: B60K 2031/0091 Speed limiters or speed cutters
• CPC Class Codes: B60K 2310/244 changing target speed or setting a new target speed, e.g. changing algorithms
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60K 31/02 including electrically actuated servomechanism including an electric control system or a servomechanism in which the vehicle velocity affecting element is actuated electrically
• CPC Class Codes: B60K 31/042 where at least one electrical quantity is set by the vehicle operator
• CPC Class Codes: B60K 31/18 including a device to audibly, visibly, or otherwise signal the existence of unusual or unintended speed to the driver of the vehicle devices primarily intended for indicating speed to other traffic B60Q1/54
• CPC Class Codes: B60K 31/185 connected to the speedometer display, e.g. by sensors or switches responsive to the position of the indicator needle arrangement of pointers in automobile speedometers for indicating predetermined speeds by the detection of the position of the indicator needle G01P1/11
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2555/60 Traffic rules, e.g. speed limits or right of way
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60Y 2400/3015 Optical cameras
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 41/0205 using an auxiliary engine speed control engine speed control per se F02D31/00
• CPC Class Codes: F02N 2300/306 with external senders or receivers, e.g. receiving signals from traffic lights, other vehicles or base stations

Abstract

Provided is a speed limiter, wherein a vehicle speed is detected, and a speed limit displayed on a speed sign is detected based on an image captured by a front monitoring camera. A speed difference between the vehicle speed and the speed limit is calculated, and an accelerator sensitivity gain is set using the speed difference as a parameter. Then an accelerator opening degree is corrected with the accelerator sensitivity gain to obtain a pseudo accelerator opening degree. A target throttle opening degree is set based on the pseudo accelerator opening degree and an engine rpm.

Claims

1. A speed limiter comprising:

a capturer for capturing a front of a subject vehicle;

a vehicle speed detector for detecting a speed of the subject vehicle;

an accelerator opening detector for detecting an accelerator opening degree that indicates a depressing amount of an accelerator pedal operated by a driver;

an engine rpm detector for detecting an engine rpm;

a speed limit detector for detecting a speed limit displayed on a speed sign, based on an image captured by the capturer;

an accelerator sensitivity gain setter for setting an accelerator sensitivity gain corresponding to a speed excess if an overspeed is detected based on a speed difference between a vehicle speed detected by the vehicle speed detector and a speed limit detected by the speed limit detector;

a pseudo accelerator opening setter for setting a pseudo accelerator opening degree by correcting an accelerator opening detected by the accelerator opening detector with an accelerator sensitivity gain set by the accelerator sensitivity gain setter; and

a target throttle opening setter for setting a target throttle opening degree based on a pseudo accelerator opening degree set by the pseudo accelerator opening setter and an engine rpm detected by the engine rpm detector.

2. The speed limiter according to claim 1, wherein even if an overspeed is detected, the accelerator sensitivity gain setter sets the accelerator sensitivity gain as a value that does not correct the accelerator opening degree within a preset time and outputs a warning signal notifying the overspeed to an alarm.

3. The speed limiter according to claim 1, wherein even if an overspeed is detected, the accelerator sensitivity gain setter sets the accelerator sensitivity gain as a value that does not correct the accelerator opening degree in the case in which the speed difference falls within a predetermined range.

4. The speed limiter according to claim 2, wherein even if an overspeed is detected, the accelerator sensitivity gain setter sets the accelerator sensitivity gain as a value that does not correct the accelerator opening degree in the case in which the speed difference falls within a predetermined range.

5. The speed limiter according to claim 1, wherein the accelerator opening degree is controlled serially as a pseudo accelerator opening degree corresponding to the speed excess which has been pressed by the driver according to the depressing amount of the accelerator pedal operated by the driver.

6. The speed limiter according to claim 1, wherein the throttle opening degree is proportional to a depressing amount of the accelerator pedal operated by the driver.

7. The speed limiter according to claim 1, further comprising a warning device configured to notify the driver if the overspeed is detected.

8. The speed limiter according to claim 1, wherein if an overspeed is detected, only the accelerator sensitivity gain decreases, and a subsequent speed increase is made by an operation of the accelerator pedal by the driver.

9. The speed limiter according to claim 1, wherein the accelerator opening degree is controlled as a pseudo accelerator opening degree corresponding to the speed excess which has been pressed by the driver according to the depressing amount of the accelerator pedal operated by the driver.

10. The speed limiter according to claim 1, wherein a plurality of accelerator sensitivity gain values are stored, each corresponding to a different speed of the subject vehicle, and

wherein the accelerator sensitivity gain setter sets the accelerator sensitivity gain according to the different speed of the subject vehicle corresponding to one of the plurality of sensitivity gain values.

11. The speed limiter according to claim 2, wherein a plurality of accelerator sensitivity gain values are stored, each corresponding to a different speed of the subject vehicle, and

wherein the accelerator sensitivity gain setter sets the accelerator sensitivity gain according to the different speed of the subject vehicle corresponding to one of the plurality of sensitivity gain values.

12. The speed limiter according to claim 1, wherein, if an overspeed is detected, the acceleration sensitivity gain is not set immediately by the accelerator sensitivity gain setter.

13. The speed limiter according to claim 1, wherein, if an overspeed is detected, the accelerator sensitivity gain setter sets the accelerator sensitivity gain as a constant value for a predetermined time.

14. The speed limiter according to claim 1, wherein, if an overspeed is detected, the accelerator sensitivity gain setter sets the accelerator sensitivity gain as a same value as a current value for a predetermined time.

15. The speed limiter according to claim 2, wherein if an overspeed is detected, only the accelerator sensitivity gain decreases, and a subsequent speed increase is made by an operation of the accelerator pedal by the driver.