JP7143711B2 - Vehicle speed sensor failure detector - Google Patents

Description

The present disclosure relates to a vehicle speed sensor failure detection device.

A vehicle speed measuring device is disclosed in Patent Document 1. The vehicle speed measuring device includes a vehicle speed sensor and a vehicle speed calculator. The vehicle speed sensor includes a vehicle speed pulse generator and a vehicle stop pulse generator. A vehicle speed pulse generator generates a vehicle speed pulse signal. The vehicle stop pulse generator generates a vehicle speed signal with a predetermined frequency even when the vehicle speed is zero.

The vehicle speed calculator calculates the vehicle speed based on the vehicle speed pulse signal. The vehicle speed calculation unit determines that the signal from the vehicle speed sensor is interrupted when the vehicle speed signal of the predetermined frequency cannot be detected. Interruption of the signal from the vehicle speed sensor corresponds to failure of the vehicle speed sensor.

JP 2006-58197 A

In the technique described in Patent Document 1, it is necessary to provide a vehicle stop pulse generator in order to detect a failure of the vehicle speed sensor. The present disclosure provides a vehicle speed sensor failure detection device capable of detecting a vehicle speed sensor failure without necessarily including a vehicle stop pulse generator.

One aspect of the present disclosure is a first signal acquisition unit configured to acquire a first signal representing vehicle speed from a vehicle speed sensor, and a second signal representing accelerator opening from an accelerator opening sensor. and a specific state in which the vehicle speed represented by the first signal is 0 and the accelerator opening represented by the second signal exceeds a preset reference value is set in advance. a continuation determination unit configured to determine whether or not the specific state continues for a reference time or longer; and if the continuation determination unit determines that the specific state has continued for the reference time or longer, the vehicle speed sensor fails. and a vehicle speed sensor failure detection device.

A vehicle speed sensor failure detection device that is one aspect of the present disclosure can detect a vehicle speed sensor failure without necessarily including a vehicle stop pulse generator.

1 is a block diagram showing a configuration of a vehicle speed sensor failure detection device 1 and members related thereto; FIG. 1 is a block diagram showing a functional configuration of a vehicle speed sensor failure detection device 1; FIG. 4 is a flowchart showing processing executed by the vehicle speed sensor failure detection device 1;

Exemplary embodiments of the present disclosure are described with reference to the drawings.
<First embodiment>
1. Configuration of Vehicle Speed Sensor Failure Detecting Device 1 The configuration of the vehicle speed sensor failure detecting device 1 and related members will be described with reference to FIGS. 1 and 2. FIG. A vehicle speed sensor failure detection device 1 is mounted on a vehicle. As shown in FIG. 1 , the vehicle includes a vehicle speed sensor 3 , an accelerator opening sensor 5 , and a notification unit 7 in addition to the vehicle speed sensor failure detection device 1 .

Vehicle speed sensor 3 outputs a first signal to vehicle speed sensor failure detection device 1 . The first signal is a vehicle speed pulse signal. The first signal is a signal representing vehicle speed.
The accelerator opening sensor 5 outputs a second signal to the vehicle speed sensor failure detection device 1 . The second signal is a signal representing the degree of opening of the accelerator. The unit of accelerator opening is %. The accelerator opening is 0% when the driver does not step on the accelerator at all. The accelerator opening is 100% when the driver depresses the accelerator to the upper limit.

The vehicle speed sensor failure detection device 1 includes a microcomputer having a CPU 9 and a semiconductor memory such as RAM or ROM (hereinafter referred to as memory 11). Each function of the vehicle speed sensor failure detection device 1 is realized by the CPU 9 executing a program stored in a non-transitional substantive recording medium. In this example, the memory 11 corresponds to a non-transitional substantive recording medium storing programs. Also, by executing this program, a method corresponding to the program is executed. The vehicle speed sensor failure detection device 1 may include one microcomputer, or may include a plurality of microcomputers.

The vehicle speed sensor failure detection device 1 includes a first signal acquisition unit 13, a second signal acquisition unit 15, a continuation determination unit 17, and a failure detection unit 19, as shown in FIG. The continuation determination unit 17 includes a first determination unit 21 , a count addition unit 23 , a reset unit 25 and a second determination unit 29 .

The method of realizing the function of each part included in the vehicle speed sensor failure detection device 1 is not limited to software, and a part or all of the function may be realized using one or more pieces of hardware. For example, when the above functions are realized by an electronic circuit that is hardware, the electronic circuit may be realized by a digital circuit, an analog circuit, or a combination thereof.

The notification unit 7 has a function of notifying by voice and display.
2. Processing Executed by Vehicle Speed Sensor Failure Detection Device 1 Processing repeatedly executed by the vehicle speed sensor failure detection device 1 at a constant cycle will be described with reference to FIG. At step 1 in FIG. 3 , the first signal acquisition unit 13 acquires the first signal from the vehicle speed sensor 3 .

In step 2 , the second signal acquisition unit 15 acquires the second signal from the accelerator opening sensor 5 .
In step 3, the first determination unit 21 determines whether or not the vehicle speed indicated by the first signal acquired in step 1 is 0 km/hr. If the vehicle speed represented by the first signal is 0 Km/hr, the process proceeds to step 4; If the vehicle speed represented by the first signal exceeds 0 km/hr, the process proceeds to step 8; The first signal when the vehicle speed is 0 km/hr is a vehicle speed pulse signal without vehicle speed pulses. The first signal when the vehicle speed exceeds 0 Km/hr is a vehicle speed pulse signal with vehicle speed pulses.

In step 4, the first determination unit 21 determines whether or not the accelerator opening indicated by the second signal acquired in step 2 exceeds 0%. If the accelerator opening indicated by the second signal exceeds 0%, the process proceeds to step 5 . If the accelerator opening indicated by the second signal is 0%, the process proceeds to step 9 . 0% corresponds to the reference value.

In step 5, the count addition unit 23 increments the count by one.
In step 6, the second judging unit 29 judges whether the count has reached a preset threshold. If the count reaches the threshold, the process proceeds to step 7; If the count has not reached the threshold, the process ends. Reaching the threshold value in the count corresponds to continuing the specific state for the reference time or longer. The time it takes for the count to reach the threshold from 0 without being prematurely reset corresponds to the reference time. The reference time is, for example, 5 minutes.

At step 7 , the failure detection unit 19 detects failure of the vehicle speed sensor 3 . The failure detection unit 19 outputs a signal indicating failure detection to the notification unit 7 . The notification unit 7 notifies that the vehicle speed sensor 3 is out of order by voice and display. The notification unit 7 may transmit information indicating that the vehicle speed sensor 3 is out of order to the outside of the vehicle. The notification unit 7 may store information indicating that the vehicle speed sensor 3 is out of order.

In step 8, the reset unit 25 determines whether the continuity condition defined below is satisfied.
Continuity condition: The first judgment unit 21 judges that the vehicle speed represented by the first signal exceeds 0 Km/hr in the above-mentioned step 3 N times or more consecutively.

If the continuity condition is satisfied, the process proceeds to step 9; If the continuity condition is not satisfied, the process ends. N is a natural number of 2 or more.
In step 9 the reset unit 25 resets the count to zero. The reset unit 25 corresponds to a vehicle speed reset unit and an accelerator opening reset unit.

3. Effect of the vehicle speed sensor failure detection device 1 (1A) When the vehicle speed sensor 3 has failed, the vehicle speed represented by the first signal is 0 km/hr, and the accelerator opening represented by the second signal exceeds 0%. continues. If the specific state continues, the vehicle speed sensor failure detection device 1 continues to increment the count, and the count reaches the threshold. Therefore, the vehicle speed sensor failure detection device 1 can detect failure of the vehicle speed sensor 3 .

(1B) The vehicle speed sensor failure detection device 1 can detect a failure of the vehicle speed sensor 3 without necessarily including a vehicle stop pulse generator.
(1C) Even if the vehicle speed sensor 3 is not out of order, the specific state may occur for a short period of time. For example, when the parking brake is on and the driver depresses the accelerator while the shift is in N or P, a specific state is entered for a short period of time. The vehicle speed sensor failure detection device 1 does not detect failure of the vehicle speed sensor 3 unless the specific state continues for a reference time or longer. Therefore, according to the vehicle speed sensor failure detection device 1, it is possible to prevent erroneous determination that the vehicle speed sensor 3 is in failure when the vehicle speed sensor 3 is in a specific state for a short period of time without failure.

As the reference time is longer, the above erroneous determination can be further suppressed. The reference time is, for example, preferably 1 minute or longer, more preferably 3 minutes or longer, and particularly preferably 5 minutes or longer.
(1D) The vehicle speed sensor failure detection device 1 determines whether the vehicle speed represented by the first signal is 0 and determines whether the accelerator opening represented by the second signal exceeds 0%. repeat in a cycle of The vehicle speed sensor failure detection device 1 increments the count each time it determines that the vehicle speed represented by the first signal is 0 and the accelerator opening represented by the second signal exceeds 0%. The vehicle speed sensor failure detection device 1 determines whether or not the count has reached a preset threshold. The vehicle speed sensor failure detection device 1 detects failure of the vehicle speed sensor 3 when determining that the count has reached the threshold value. Therefore, the vehicle speed sensor failure detection device 1 can detect failure of the vehicle speed sensor 3 with a simple configuration.

(1E) The vehicle speed sensor failure detection device 1 resets the count on the condition that the vehicle speed represented by the first signal is determined to be not 0 a plurality of times in succession. Therefore, when the vehicle speed represented by the first signal is temporarily determined to be not 0 due to the influence of noise or the like, the vehicle speed sensor failure detection device 1 does not reset the count. Therefore, the vehicle speed sensor failure detection device 1 can detect failure of the vehicle speed sensor 3 more accurately.

(1F) The vehicle speed sensor failure detection device 1 resets the count under the condition that the accelerator opening represented by the second signal is determined to be 0%. Therefore, the vehicle speed sensor failure detection device 1 can detect failure of the vehicle speed sensor 3 more accurately.
<Other embodiments>
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made.

(1) The first signal may be a signal other than the vehicle speed pulse signal.
(2) The reference value used in step 4 may be a value other than 0%. The reference value used in step 4 may be, for example, 1%, 3%, 5%, or the like.

(3) The vehicle speed sensor failure detection device 1 may estimate the duration of the specific state by a method other than adding counts.
(4) If the determination in step 3 is negative, the process may always proceed to step 9 to reset the count. If a negative determination is made in step 3, the count may not be reset. If a negative determination is made in step 4, the count may not be reset.

(5) The vehicle speed sensor failure detection device 1 may be a device fixed to the vehicle or a portable device. The vehicle speed sensor failure detection device 1 may be a smart phone, a tablet terminal, or the like.

(6) A plurality of functions possessed by one component in the above embodiment may be realized by a plurality of components, or a function possessed by one component may be realized by a plurality of components. . Also, a plurality of functions possessed by a plurality of components may be realized by a single component, or a function realized by a plurality of components may be realized by a single component. Also, part of the configuration of the above embodiment may be omitted. Also, at least part of the configuration of the above embodiment may be added or replaced with respect to the configuration of the other above embodiment.

(7) In addition to the vehicle speed sensor failure detection device described above, a system having the vehicle speed sensor failure detection device as a component, a program for causing a computer to function as the vehicle speed sensor failure detection device, a semiconductor memory storing this program, etc. The present disclosure can also be implemented in various forms such as a non-transitional physical recording medium, a vehicle speed sensor failure detection method, and the like.

DESCRIPTION OF SYMBOLS 1... Vehicle speed sensor failure detection apparatus 3... Vehicle speed sensor 5... Accelerator opening sensor 7... Notification part 9... CPU 11... Memory 13... First signal acquisition unit 15... Second signal acquisition unit 17 continuation determination unit 19 failure detection unit 21 first determination unit 23 count addition unit 25 reset unit 29 second determination unit

Claims (2)

a first signal acquisition unit configured to acquire a first signal indicative of vehicle speed from a vehicle speed sensor;
a second signal acquisition unit configured to acquire a second signal representing the accelerator opening from the accelerator opening sensor;
Determining whether or not a specific state in which the vehicle speed indicated by the first signal is zero and the degree of opening of the accelerator indicated by the second signal exceeds a preset reference value continues for a preset reference time or longer. a continuation determination unit configured to
a failure detection unit that detects a failure of the vehicle speed sensor when the continuation determination unit determines that the specific state continues for the reference time or longer;
with
The continuation determination unit
A first determination unit that repeatedly determines whether the vehicle speed represented by the first signal is 0 and determines whether the accelerator opening represented by the second signal exceeds the reference value at regular intervals. When,
a count addition unit that adds a count each time the first determination unit determines that the vehicle speed represented by the first signal is 0 and the accelerator opening represented by the second signal exceeds the reference value;
a vehicle speed reset unit for resetting the count on condition that the first determination unit continuously determines that the vehicle speed represented by the first signal is not zero;
a second determining unit configured to determine whether the count has reached a preset threshold;
an accelerator opening reset unit that resets the count on condition that the first determination unit determines that the accelerator opening represented by the second signal is equal to or less than the reference value;
A vehicle speed sensor failure detection device. The vehicle speed sensor failure detection device according to claim 1 ,
The vehicle speed sensor failure detection device, wherein the first signal is a vehicle speed pulse signal.

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