JP6228829B2 - Electronic key - Google Patents

Description

  The present invention relates to an electronic key.

  2. Description of the Related Art Conventionally, an electronic key that performs locking / unlocking of a vehicle door, permission to start an engine, and the like through wireless communication with a vehicle side is known. The electronic key is provided with various switches such as a lock switch and an unlock switch for locking and unlocking the vehicle door, and a window opening switch and a window closing switch for electrically opening and closing the vehicle window. The user can perform the above-described various controls by operating each switch of the electronic key even at a position away from the vehicle (see, for example, Patent Document 1).

  In the electronic key described in Patent Document 1, when operating each switch, the user has to take out the electronic key stored in his / her clothes pocket, etc., visually confirm the desired switch, and press the switch. Such work is troublesome for the user.

  In view of this, the electronic key described in Patent Document 2 is considered to be configured so that it can be operated by tapping the electronic key. The electronic key has a built-in acceleration sensor. The electronic key determines the presence or absence of a tapping operation based on the detection result of the acceleration sensor.

JP 7-54525 A JP 2010-275701 A

  For example, the electronic key described in Patent Document 1 is used for an electronic key when the acceleration detected by the acceleration sensor is equal to or greater than a threshold and the acceleration detection period that is equal to or greater than the threshold is less than the threshold time. To determine that a tapping operation has been performed. In this configuration, it is possible to determine that the electronic key has been tapped by mistake by satisfying the above condition by the acceleration generated when the electronic key falls (referred to as free fall, the same applies hereinafter) and collides with the ground. There is.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an electronic key with improved determination accuracy relating to the presence or absence of a tapping operation.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
An electronic key that solves the above problem includes an acceleration sensor that detects an acceleration generated in an electronic key carried by a user, and a determination unit that determines presence or absence of a hitting operation based on a detection result of the acceleration sensor. The means is that the acceleration detected through the acceleration sensor is equal to or greater than a first threshold value set to be less than an acceleration assumed to occur at the time of hitting the electronic key, and an acceleration of the hitting operation is increased. It is determined that a hit operation has been performed on the condition that the detected acceleration is equal to or less than a second threshold value after a certain period of time assumed to have no effect.

  According to this configuration, the determination means is detected when the acceleration detected through the acceleration sensor is equal to or more than the first threshold and when a certain time is assumed that the influence of the acceleration accompanying the hitting operation is eliminated. It is determined that the hit operation has been performed on the condition that the acceleration is equal to or less than the second threshold value. For this reason, for example, when an electronic key falls, the electronic key collides with the ground, the electronic key bounces by the collision, and the electronic key collides with the ground again. For this reason, when the electronic key is dropped, the acceleration detected through the acceleration sensor by the first collision is equal to or higher than the first threshold, but the acceleration detected by the second collision after a predetermined time has passed. The second threshold is exceeded. Therefore, when the electronic key is dropped, it can be prevented that it is erroneously determined that there is a hitting operation. For this reason, it is possible to improve the determination accuracy related to the presence or absence of the hitting operation.

Regarding the electronic key, it is preferable that the determination unit determines that a hit operation has been performed on the condition that 0G is not detected in addition to the two conditions.
When the electronic key is falling, the acceleration sensor detects 0G. Focusing on this point, according to the above configuration, the determination unit determines that a hit operation has been performed on the condition that 0G is not detected in addition to the above two conditions. That is, when 0G is detected, the determining means does not determine that the electronic key has been dropped and that it is a hitting operation. As described above, by increasing the determination conditions related to the hit operation, it is possible to improve the determination accuracy related to the presence or absence of the hit operation.

  With respect to the electronic key, it is preferable that the second threshold value is set to be smaller than the first threshold value and to be smaller than an acceleration caused by a second collision on the ground after the electronic key bounces.

  According to this configuration, the second threshold value is set to be smaller than the first threshold value and smaller than the acceleration caused by the second and subsequent collisions with the ground due to the bounce of the electronic key. Therefore, when the electronic key is dropped, erroneous determination that a hit operation has been performed is more reliably suppressed.

With respect to the electronic key, it is preferable that the predetermined time is set to a time from when the electronic key is dropped and collides with the ground until the second collision with the ground.
According to this configuration, the predetermined time is set to the time from when the electronic key falls and collides with the ground until the second collision with the ground. Therefore, when the electronic key is dropped, erroneous determination that a hit operation has been performed is more reliably suppressed.

According to the present invention, it is possible to more accurately determine the presence or absence of a hitting operation on an electronic key.

The block diagram of an electronic key system. The flowchart which showed the process sequence which a microcomputer performs. The graph which showed transition of the acceleration detected by the acceleration sensor at the time of hitting operation with respect to an electronic key. The graph which showed transition of the acceleration detected by the acceleration sensor at the time of fall of an electronic key. The graph which showed transition of the acceleration detected by the acceleration sensor at the time of throwing up an electronic key.

Hereinafter, an embodiment in which an electronic key is embodied in an electronic key system will be described with reference to FIGS. In this embodiment, the vehicle is equipped with a wireless key system as the electronic key system 1 . As shown in FIG. 1, the wireless key system is a system that performs remote control of a vehicle through unidirectional wireless communication from the electronic key 2 to the in-vehicle device 3 that is triggered by a tapping operation on the electronic key 2.

(Configuration of electronic key 2)
As shown in FIG. 1, the electronic key 2 includes a microcomputer 23, a transmission circuit 24, a transmission antenna 25, and an acceleration sensor 21. The microcomputer 23 is an example of a determination unit.

  The acceleration sensor 21 outputs the acceleration applied when the electronic key 2 is hit to the microcomputer 23 as a detection result. The acceleration sensor 21 may be a mechanical type, an optical type, a semiconductor type, or the like, but any sensor that can be built in the electronic key 2 and can detect an impact (acceleration) on the electronic key 2 may be used.

  The microcomputer 23 includes a nonvolatile memory 23a. In the memory 23a, there are a threshold value for determining whether or not the acceleration detected by the acceleration sensor 21 is due to a hitting operation related to locking / unlocking of the vehicle door, an ID code individually set for each electronic key 2, and the like. It is remembered. The microcomputer 23 determines the presence or absence of a hitting operation based on the detection result of the acceleration sensor 21.

Specifically, the microcomputer 23 determines that the electronic key 2 has been hit when the following first to third conditions are satisfied.
First condition: Do not detect 0G for a certain period of time Ta or more Second condition: Detect acceleration that is greater than or equal to the first threshold Tth1, and the acceleration detection period Tc that is greater than or equal to the first threshold Tth1 is within the threshold time Ttha The third condition is that the detected threshold is equal to or less than the second threshold Tth2 at the time tb when a certain time Tb has elapsed from the time ta when the detected acceleration is equal to or greater than the first threshold Tth1. The first threshold Tth1 is the electronic key 2 The acceleration is set to be less than the acceleration expected to occur during the tapping operation. The threshold time Ttha is set based on the time during which an acceleration equal to or greater than the first threshold Tth1 is detected when the electronic key 2 is hit. The second threshold value Tth2 is set to be smaller than the first threshold value Tth1 and smaller than the acceleration generated by the second collision with the ground when the electronic key 2 bounces (bounces). Further, the predetermined time Tb is set to a time when it is assumed that the influence of the acceleration accompanying the hitting operation on the electronic key 2 is eliminated. Specifically, the fixed time Tb is set to a time from when the electronic key 2 falls and first collides with the ground to the second collision with the ground. Further, the fixed time Ta is set based on the average drop time of the electronic key 2.

In accordance with the flowchart of FIG. 2, the microcomputer 23 determines whether or not the first to third conditions are satisfied.
Specifically, first, the microcomputer 23 determines whether or not the first condition is satisfied (S101). When the microcomputer 23 determines that the first condition is satisfied (YES in S101), the microcomputer 23 determines whether or not the second condition is satisfied (S102). Next, when determining that the second condition is satisfied (YES in S102), the microcomputer 23 determines whether or not the third condition is satisfied (S103). If the microcomputer 23 determines that the third condition is satisfied (YES in S103), the microcomputer 23 determines that the operation is a tapping operation on the electronic key 2 (S10 4 ).

  On the other hand, when the microcomputer 23 determines that any one of the first to third conditions is not satisfied (NO in S101 to S103), the microcomputer 23 determines that the electronic key 2 is not hit (S105). As described above, the microcomputer 23 determines whether or not the electronic key 2 is hit.

  When the microcomputer 23 determines that the electronic key 2 is a hit operation, the microcomputer 23 generates an unlocking / unlocking request signal including an operation code for requesting the vehicle to switch the door locking / unlocking state and the ID code of the electronic key 2. To do. Then, the microcomputer 23 outputs this locking / unlocking request signal to the transmission circuit 24. The transmission circuit 24 modulates the lock / unlock request signal input from the microcomputer 23 into a radio wave of a predetermined frequency band. In the present embodiment, the predetermined frequency band is a UHF (Ultra High Frequency) band. The transmission antenna 25 wirelessly transmits the locking / unlocking request signal modulated by the transmission circuit 24.

On the other hand, when the microcomputer 23 determines that it is not a hit operation with respect to the electronic key 2, it does not wirelessly transmit the locking / unlocking request signal.
(Configuration of in-vehicle device 3)
As shown in FIG. 1, the in-vehicle device 3 includes a receiving antenna 31, a receiving circuit 32, and an in-vehicle control unit 33.

  The in-vehicle control unit 33 includes a non-volatile memory 33a, and the memory 33a stores the same ID code as the ID code of the electronic key 2 suitable for the vehicle on which the in-vehicle device 3 is mounted.

  The receiving antenna 31 receives the lock / unlock request signal wirelessly transmitted from the electronic key 2. The reception circuit 32 demodulates the lock / unlock request signal received by the reception antenna 31 to generate a reception signal, and outputs the reception signal to the in-vehicle control unit 33. When the verification of the ID code included in the received signal and the ID code stored in the memory 33a is established, the in-vehicle control unit 33 switches the lock to the door control device 40 according to the operation code included in the received signal. A command signal is output. Upon receiving the locking / unlocking switching command signal, the door control device 40 switches the door locking / unlocking state.

(Function)
Next, according to FIGS. 3 to 5, the change in acceleration when the electronic key 2 is hit, when the electronic key 2 is dropped, and when the electronic key 2 is thrown up, and the first to the above-described first to the above. The success or failure of the third condition will be described.

  As shown in FIG. 3, when the electronic key 2 is located in the hand, the acceleration sensor 21 is in a state of detecting an acceleration of about 1G. When the electronic key 2 is hit from this state, the acceleration of the convex waveform S1 is detected. In the convex waveform S1 accompanying the hitting operation in FIG. 3, the first condition is satisfied because 0G is not detected. Moreover, since the acceleration more than 1st threshold value Tth1 is detected and the detection period Tc becomes less than threshold time Ttha, 2nd conditions are also satisfy | filled. Furthermore, since the detected acceleration becomes equal to or less than the second threshold value Tth2 at time tb after a certain time Tb has elapsed since time ta when the detected threshold value becomes equal to or greater than the first threshold value Tth1, the third condition is also satisfied. Therefore, the microcomputer 23 determines that there has been a tapping operation on the electronic key 2 assuming that the first to third conditions are satisfied, and wirelessly transmits a locking / unlocking request signal.

  Next, as shown in FIG. 4, when the electronic key 2 falls and collides with the ground, when the fall starts, the detected acceleration changes from 1G to 0G, and the fall continues. 0G is maintained throughout. When the electronic key 2 first collides with the ground, the acceleration of the first convex waveform S1 is detected. Thereafter, when the electronic key 2 bounces and the electronic key 2 collides with the ground again, the acceleration of the second convex waveform S2 smaller than the first convex waveform S1 is detected.

  If the drop time of the electronic key 2 is equal to or longer than the predetermined time Ta, 0G equal to or longer than the predetermined time Ta is detected, so the first condition is not satisfied. On the other hand, if the drop time of the electronic key 2 is less than the predetermined time Ta, 0G longer than the predetermined time Ta is not detected, so the first condition is satisfied. Thus, even when the electronic key 2 is falling, the first condition may be satisfied. Further, since the acceleration of the first threshold Tth1 is detected by the first convex waveform S1 and the detection period Tc is within the threshold time Ttha, the second condition is also satisfied.

  Even if the first and second conditions are satisfied, a certain time Tb has elapsed since the time ta when the acceleration detected by the second convex waveform S2 is equal to or greater than the first threshold Tth1. Since acceleration exceeding the second threshold Tth2 is detected at time tb, the third condition is not satisfied. Therefore, the microcomputer 23 determines that there is no tapping operation with respect to the electronic key 2 on the assumption that at least the third condition is not satisfied, and does not wirelessly transmit the locking / unlocking request signal.

  Next, as shown in FIG. 5, when the electronic key 2 is thrown up, an acceleration equal to or greater than the first threshold value Tth1 is detected, but since the detection period Tc exceeds the threshold time Ttha, at least the second threshold value Tth1 is detected. The condition is not met. Therefore, the microcomputer 23 determines that there is no tapping operation with respect to the electronic key 2 on the assumption that at least the second condition is not satisfied, and does not wirelessly transmit the locking / unlocking request signal.

  In addition, for example, it is assumed that the electronic key 2 is continuously swung twice. In this case, even if the second condition is satisfied by the first swing operation, the acceleration exceeding the second threshold Tth2 is detected at time tb by the convex waveform of the acceleration accompanying the second swing operation. The third condition is not satisfied. Therefore, the microcomputer 23 determines that there is no tapping operation with respect to the electronic key 2 on the assumption that at least the third condition is not satisfied, and does not wirelessly transmit the locking / unlocking request signal.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) The microcomputer 23 detects the acceleration detected through the acceleration sensor 21 after the elapse of a predetermined time Tb that is assumed to be equal to or greater than the first threshold value Tth1 and the influence of the acceleration accompanying the hitting operation is eliminated. It is determined that the hit operation has been performed on the condition that the acceleration is equal to or less than the second threshold value Tth2. For this reason, for example, when the electronic key 2 falls, the electronic key 2 first collides with the ground, the electronic key 2 bounces due to the collision, and the electronic key 2 collides with the ground again. For this reason, although the acceleration detected through the acceleration sensor 21 by the first collision becomes equal to or greater than the first threshold Tth1, the acceleration detected by the second collision after the lapse of the predetermined time Tb has the second threshold Tth2. Exceed. Therefore, when the electronic key 2 falls, it can be suppressed that it is determined that there is a hitting operation by mistake. For this reason, it is possible to improve the determination accuracy related to the presence or absence of the hit operation.

  (2) When the electronic key 2 is falling, the acceleration sensor 21 detects 0G. Focusing on this point, in addition to the above two conditions, the microcomputer 23 determines that there has been a tapping operation on the condition that 0G for a predetermined time Ta or more is not detected. That is, when the microcomputer 23 detects 0G that is equal to or longer than the predetermined time Ta, the microcomputer 23 does not determine that the electronic key 2 has been dropped and is a hit operation. For this reason, it is possible to improve the determination accuracy related to the presence or absence of the hitting operation.

  (3) The second threshold value Tth2 is set to be smaller than the first threshold value Tth1 and smaller than the acceleration generated by the second collision with the ground when the electronic key 2 bounces. Therefore, when the electronic key 2 is dropped, erroneous determination that the hit operation has been performed is more reliably suppressed.

  (4) The fixed time Tb is set to the time from when the electronic key 2 falls and first collides with the ground until the second collision with the ground. Therefore, when the electronic key 2 is dropped, erroneous determination that the hit operation has been performed is more reliably suppressed.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above embodiment, the first condition is that 0G that is equal to or longer than the predetermined time Ta is not detected, but the first condition may be that 0G is not detected.

  In the above-described embodiment, the second condition is that an acceleration greater than or equal to the first threshold value Tth1 is detected and the detection period Tc is within the threshold time Ttha, but the second condition is that the first condition is It is also possible to detect an acceleration equal to or greater than the threshold value Tth1.

The microcomputer 23 may omit the first condition.
In the above embodiment, the fixed time Tb is measured from the time ta when the detected acceleration is equal to or greater than the first threshold value Tth1, but not limited to this, the fixed time Tb includes the detected acceleration. You may measure from the time which became 1st threshold value Tth1 or less after becoming 1st threshold value Tth1 or more.

Next, the technical idea that can be grasped from the embodiment will be described together with the effects.
(B) In addition to the above two conditions, the determination means is an electronic key that determines that there has been a tapping operation on condition that 0G longer than a predetermined time set based on the drop time of the electronic key is not detected.

  DESCRIPTION OF SYMBOLS 1 ... Electronic key system, 2 ... Electronic key, 3 ... In-vehicle apparatus, 21 ... Acceleration sensor, 23 ... Microcomputer, 33 ... In-vehicle control part.

Claims (2)

An acceleration sensor for detecting acceleration generated in an electronic key carried by the user;
Determination means for determining the presence or absence of a hitting operation based on the detection result of the acceleration sensor,
The determination means detects that the acceleration detected through the acceleration sensor is equal to or higher than a first threshold value set to be less than an acceleration assumed to be generated when the electronic key is hit, and is detected through the acceleration sensor. The time when the measured acceleration is greater than or equal to the first threshold is within the threshold time, and the moment when the acceleration detected through the acceleration sensor is greater than or equal to the first threshold or detected through the acceleration sensor After the acceleration becomes equal to or higher than the first threshold , the detected acceleration is detected when a certain time elapses from the moment the acceleration becomes equal to or lower than the first threshold. An electronic key that determines that a hit operation has been performed on condition that the second threshold value or less. The electronic key according to claim 1, wherein
The judgment unit may, in addition to the three conditions, the electronic key to determine that there is a beating operation on condition that the falling does not detect the specified time or more 0G time is set based on the electronic key.