Kick sensor, vehicle, and kicking motion detection method

Abstract

This kick sensor detects a kick motion of a user, and, in order to reduce erroneous detection in which a motion different from a kick motion is detected as a kick motion, comprises: a sensor unit that is provided to a vehicle and that detects the approach or separation of a subject; and a control unit that determines a motion of the subject on the basis of a detection result of the sensor unit. The control unit calculates a first distance by which the subject has approached the sensor unit and a second distance by which the subject has been separated from the sensor unit, and determines that a kick motion has been performed when the first distance is within a first distance range, the second distance is within a second distance range, and a first distance ratio obtained by dividing the second distance by the first distance is less than a first threshold value.

Description

[Technical Field]

[0001] The present invention relates to a kick sensor, a vehicle, and a method for detecting a kicking motion. [Background technology]

[0002] In vehicles such as automobiles, there are systems that detect a kicking motion by a user's legs or the like to open and close a back door, etc. Also, a kick sensor that detects a kicking motion by a user's legs or the like is known (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-96128 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for reducing false detections in kick sensors, where movements other than kicks are mistakenly determined to be kicking movements.

[0005] For example, the technology disclosed in Patent Document 1 detects motion by calculating the time when the sensor output value exceeds a threshold. This method has the problem that, for example, even if a movement is different from a kicking movement, if the time when the threshold value is exceeded is the same as that of a kicking movement, it may be determined to be a kicking movement.

[0006] One embodiment of the present invention has been made in consideration of the above-mentioned problems, and reduces the chance of a kick sensor that detects a kicking motion by a user mistakenly detecting a motion that is different from a kicking motion as a kicking motion. [Means for solving the problem]

[0007] In order to solve the above problem, a kick sensor according to one embodiment of the present invention is provided in a vehicle and comprises a sensor unit that detects the approach and departure of an object, and a control unit that determines the movement of the object based on the detection results of the sensor unit, wherein the control unit calculates a first distance at which the object approaches the sensor unit and a second distance at which the object moves away from the sensor unit, and determines that a kick action has been performed if the first distance is within a first distance range, the second distance is within a second distance range, and a first distance ratio obtained by dividing the second distance by the first distance is less than a first threshold value. [Effects of the Invention]

[0008] According to one embodiment of the present invention, in a kick sensor that detects a kicking motion by a user, it is possible to reduce the chance of a motion that is different from a kicking motion being mistakenly detected as a kicking motion. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of a system configuration of an in-vehicle system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram (1) for explaining an outline of processing according to the present embodiment. [Figure 3] FIG. 2 is a diagram (2) for explaining an outline of the processing according to the present embodiment. [Figure 4] FIG. 3 is a diagram for explaining an outline of the processing according to the present embodiment. [Figure 5] FIG. 4 is a diagram (4) for explaining an outline of the processing according to the present embodiment. [Figure 6] FIG. 5 is a diagram (5) for explaining an outline of the processing according to the present embodiment. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a computer according to the present embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of a functional configuration of a control unit according to the present embodiment. [Figure 9] 10 is a flowchart illustrating an example of a process for detecting a kicking motion according to the present embodiment. [Figure 10] 10 is a flowchart illustrating an example of a feature extraction process according to the present embodiment. [Figure 11A] 1 is a flowchart (1) illustrating an example of a distance ratio determination process according to the present embodiment. [Figure 11B] 10 is a flowchart (2) illustrating an example of a distance ratio determination process according to the present embodiment. [Figure 11C] 10 is a flowchart (3) illustrating an example of a distance ratio determination process according to the present embodiment. [Figure 11D] 10 is a flowchart (4) illustrating an example of a distance ratio determination process according to the present embodiment. [Figure 11E] 10 is a flowchart (5) illustrating an example of a distance ratio determination process according to the present embodiment. [Figure 11F] 10 is a flowchart (6) illustrating an example of a distance ratio determination process according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the accompanying drawings.

[0011] <System configuration> Fig. 1 is a diagram showing an example of the configuration of an in-vehicle system according to this embodiment. The in-vehicle system 1 is a system that detects a kicking motion by a user's leg 2 or the like using a kick sensor 100 provided in a vehicle 10 such as an automobile, and opens and closes the doors of the vehicle 10. In the example of Fig. 1, the in-vehicle system 1 includes the kick sensor 100 provided in the rear of the vehicle 10, and an electronic control unit (ECU: Electric Control Unit) 12 that controls the opening and closing of a back door (or trunk) 11.

[0012] The kick sensor 100 includes a sensor unit 101 that detects the approach and departure of an object, and a control unit 102 that determines the movement of the object based on the detection results of the sensor unit 101. The sensor unit 101 is, for example, a Doppler radar, and the control unit 102 acquires the speed of the object (the user's leg 2) approaching the sensor unit 101 and the speed of the object moving away from the sensor unit 101 based on the output signal of the sensor unit 101.

[0013] The control unit 102 accumulates the speed of the object while it is approaching the sensor unit 101, and calculates the distance by which the object has approached the sensor unit 101 (hereinafter referred to as the first distance). Similarly, the control unit 102 accumulates the speed of the object while it is moving away from the sensor unit 101, and calculates the distance by which the object has moved away from the sensor unit 101 (hereinafter referred to as the second distance).

[0014] In addition, the control unit 102 detects that a kicking motion has been performed by the user's leg 2, etc., based on the first distance at which the object approaches the sensor unit 101, the second distance at which the object moves away from the sensor unit 101, and the distance ratio between the first distance and the second distance, and outputs the detection result.

[0015] The electronic control unit 12 opens and closes the back door 11 of the vehicle 10 based on the detection result of the kick operation output from the control unit 102. Note that the system configuration of the in-vehicle system 1 shown in FIG. 1 is an example. For example, the control unit 102 of the kick sensor 100 and the electronic control unit 12 may be realized by a single ECU. Furthermore, the electronic control unit 12 may control the opening and closing of doors other than the back door 11 of the vehicle 10 based on the detection result from the kick sensor 100.

[0016] Furthermore, the sensor unit 101 is not limited to a Doppler radar that measures speed, but may be a pulse radar that measures distance, or an FM-CW (Frequency Modulated Continuous Wave radar) radar, etc. Furthermore, the sensor unit 101 is not limited to a radar, but may be, for example, an ultrasonic sensor that measures distance, etc.

[0017] Here, as an example, the following description will be given assuming that the sensor unit 101 is a Doppler radar. Doppler radar measures the speed of an object, making it easy to detect when an object begins to approach the sensor unit 101 or when the direction of the object's movement has reversed. In the following description, Doppler radar may be simply referred to as radar.

[0018] (Processing Overview) 2 to 6 are diagrams for explaining an outline of the processing according to this embodiment. As shown in Fig. 2, the sensor unit 101 detects the approach and departure of the user's leg 2 by transmitting a signal within a radar detection range 201 and measuring the amplitude of the received signal that is reflected by an object.

[0019] The kicking motion has four states: standby (S1) in which the leg 2 is stationary, approach (S2) in which the leg 2 is approaching the sensor unit 101, separation (S3) in which the leg 2 is moving away from the sensor unit 101, and end (S4) in which the kick has ended and the leg is stationary. When these four states are observed with a Doppler radar, observation data such as that shown in Figure 3 is obtained.

[0020] In Fig. 3, the horizontal axis represents the passage of time, and the vertical axis represents the velocity 301 of the object (user's leg 2). In Fig. 3, velocity 301 becomes a positive value from time t1, indicating an approaching (S2) state in which the object is approaching the sensor unit 101. Furthermore, velocity 301 becomes zero at time t2, and then becomes a negative value, indicating a separating (S3) state in which the object is moving away from the sensor unit 101. Furthermore, velocity 301 becomes zero from time t3, indicating an end (S4) state in which the kicking motion has ended.

[0021] 3, the control unit 102 calculates a first distance, which is the distance the object approaches the sensor unit 101, and a second distance, which is the distance the object moves away from the sensor unit 101. For example, the control unit 102 accumulates the speed of the object while it is approaching the sensor unit 101 to calculate the first distance, and accumulates the speed of the object while it is moving away from the sensor unit 101 to calculate the second distance.

[0022] When the first distance x and the second distance y calculated by the control unit 102 are plotted on the x and y coordinates to show the relationship between the first distance x and the second distance y of a plurality of movements, a graph 400 such as that shown in Fig. 4 is obtained. The graph 400 shows an example of data 401 obtained from a kicking movement and data 402 obtained from a movement other than a kicking movement.

[0023] Here, actions other than kicking actions include, for example, actions such as wiping the area around the bumper of the vehicle 10, walking around the bumper, bringing an object close to the bumper, moving a ball or the like under the bumper, splashing water around the bumper, unloading luggage into the trunk of the vehicle 10, moving one's legs while sitting in the trunk, getting in and out of the vehicle, or leaving the vehicle 10 in a rainy environment.

[0024] In Figure 4, x min is the lower limit of the first distance x, and x max is the upper limit of the first distance x. min is a threshold value for excluding, as a kicking motion, a motion in which the first distance x at which the object approaches the sensor unit 101 is too small. max is a threshold value for excluding, as a kicking motion, a motion in which the first distance x at which the object approaches the sensor unit 101 is too large.

[0025] Similarly, y min is the lower limit of the second distance y, and y max is the upper limit of the second distance y. min is a threshold value for excluding, as a kicking motion, a motion in which the second distance y by which the object moves away from the sensor unit 101 is too small.max is a threshold value for excluding, as a kicking motion, a motion in which the second distance y by which the object moves away from the sensor unit 101 is too large.

[0026] In the example of FIG. 4, the lower limit x of the first distance x min is the lower limit y of the second distance y min When the distance between the vehicle 10 and the user is very short, the user often steps back a little after performing the kicking motion. Therefore, the lower limit value x of the first distance x is min the lower limit y of the second distance y min By making it smaller, the control unit 102 can accurately detect the kicking motion even when the distance between the vehicle 10 and the user is extremely short.

[0027] The control unit 102 determines whether the calculated first distance x is x min From x max If the calculated second distance y is not within the first distance range from y min From y max If the detected motion is not within the second distance range, the control unit 102 determines that the motion is not a kicking motion. This allows the control unit 102 to reduce the number of times that a motion other than a kicking motion is mistakenly detected as a kicking motion.

[0028] However, since the first distance range and the second distance range need to be set wide to take into account individual differences, it is difficult to sufficiently prevent movements that are different from kicking movements from being mistakenly detected as kicking movements.

[0029] Therefore, in this embodiment, the distance ratio between the first distance at which the object approaches the sensor unit 101 and the second distance at which the object moves away from the sensor unit 101 is used as a feature for detecting a kicking motion.

[0030] A person with a long first distance x in a kicking motion will also have a long second distance y, and a person with a short first distance x will also have a short second distance y. Therefore, the ratio of the first distance x to the second distance y varies little among individuals, and the range within which a kicking motion is determined to have been performed can be set narrowly.

[0031] Specifically, the control unit 102 determines that a kicking motion has been performed when the first distance x is within a first distance range, the second distance y is within a second distance range, and the distance ratio of the first distance x to the second distance y is within a predetermined range.

[0032] For example, when a user performs a kicking motion while approaching vehicle 10, many people move their leg behind their supporting leg, kick up, and then align their kicking leg next to their supporting leg. Therefore, the first distance x is often greater than the second distance y, and if the second distance y is excessively greater than the first distance x, it is unlikely that the motion is a kicking motion.

[0033] Therefore, in this embodiment, as shown in Fig. 5, a first distance ratio obtained by dividing the second distance y by the first distance x is used to determine whether a kicking motion or a motion other than a kicking motion is represented by a first threshold value 501. For example, the control unit 102 determines that a kicking motion has been performed when the first distance x is within the first distance range, the second distance y is within the second distance range, and the first distance ratio obtained by dividing the second distance y by the first distance x is less than the first threshold value 501. This allows the control unit 102 to further reduce the likelihood of erroneously determining that data 402 obtained by a motion other than a kicking motion, for example, in the area 403 of Fig. 5, is a kicking motion.

[0034] Preferably, in this embodiment, as shown in Fig. 6, a second threshold value 601 is further set to determine whether a second distance ratio obtained by dividing the first distance x by the second distance y indicates a kicking motion or a motion other than a kicking motion. Furthermore, the control unit 102 determines that a kicking motion has been performed when the first distance x is within the first distance range, the second distance y is within the second distance range, and the second distance ratio obtained by dividing the first distance x by the second distance y is less than the second threshold value 601. This allows the control unit 102 to further prevent, for example, data 602 obtained by a motion other than a kicking motion, which is in the area 404 of Fig. 6, from being erroneously determined to be a kicking motion.

[0035] As described above, according to this embodiment, it is possible to reduce the chance that the kick sensor 100 that detects a kicking motion by a user mistakenly detects a motion that is different from a kicking motion as a kicking motion.

[0036] <Hardware configuration> The control unit 102 of the kick sensor 100 and the electronic control device 12 have, for example, the hardware configuration of a computer 700 as shown in FIG.

[0037] 7 is a diagram showing an example of the hardware configuration of a computer according to this embodiment. The computer 700 includes, for example, a processor 701, a memory 702, a storage device 703, a communication I / F (Interface) 704, an external connection I / F 705, and a bus 706.

[0038] The processor 701 is, for example, an arithmetic device such as a CPU (Central Processing Unit) that realizes various functions by executing predetermined programs stored in a storage medium such as a storage device 703 or a memory 702. The memory 702 includes, for example, a RAM (Random Access Memory), which is a volatile memory used as a work area or the like for the processor 701, and a ROM (Read Only Memory), which is a non-volatile memory that stores programs such as startup programs for the processor 701. The storage device 703 is a large-capacity storage device that stores an OS (Operating System), programs such as applications, and various data, information, and the like, and is realized by, for example, an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0039] The communication I / F 704 is an interface for connecting the computer 700 to a communication network such as an in-vehicle network to communicate with other devices. The external connection I / F 705 is an interface for connecting an external device such as the sensor unit 101 to the computer 700. The bus 706 is commonly connected to the above components and transmits, for example, address signals, data signals, and various control signals.

[0040] 7 is an example. For example, the processor 701 may further include, in addition to a CPU, a DSP (Digital Signal Processor) or a GPU (Graphics Processing Unit). The processor 701 may be implemented by a hardware device such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The computer 700 may be implemented by an MCU (Micro Controller Unit) or an SoC (System on a chip).

[0041] <Functional configuration> 8 is a diagram showing an example of the functional configuration of the control unit according to this embodiment. The control unit 102 of the kick sensor 100 realizes a signal processing unit 801, an extraction unit 802, a detection unit 803, etc., by, for example, the processor 701 executing a predetermined program. Note that at least a part of the above functional configurations may be realized by hardware.

[0042] The signal processing unit 801 executes signal processing to acquire the velocity of an object, the amplitude value of the received signal, and the like from the received signal output by the sensor unit 101. For example, if the sensor unit 101 is a radar, the signal processing unit acquires an RSSI (Received Signal Strength Indicator) indicating the strength of the received signal as the amplitude value.

[0043] The extraction unit 802 extracts a first distance x at which the object approaches the sensor unit 101 and a second distance y at which the object moves away from the sensor unit 101 from the speed of the object output by the signal processing unit 801. For example, the extraction unit 802 accumulates the speed while the object is approaching the sensor unit 101 to calculate the first distance x, and accumulates the speed while the object is moving away from the sensor unit 101 to calculate the second distance y.

[0044] Furthermore, the extraction unit 802 stores (or outputs) the maximum amplitude value A of the received signal received from the start of measurement of the first distance x until the end of measurement of the second distance y.

[0045] The detection unit 803 detects a kicking motion based on the first distance x and the second distance y extracted by the extraction unit 802. For example, as described with reference to FIGS. 4 and 5, the detection unit 803 determines that a kicking motion has been performed when the first distance x is within the first distance range, the second distance y is within the second distance range, and the first distance ratio y / x is less than the first threshold value 501.

[0046] Preferably, the detection unit 803 further determines that a kicking motion has been performed when the first distance x is within a first distance range, the second distance y is within a second distance range, and the second distance ratio x / y is less than a second threshold 601, as described in FIG. 6 .

[0047] 8 is an example. The control unit 102 may have any functional configuration as long as it can execute the processes of the signal processing unit 801, the extraction unit 802, and the detection unit 803 described above.

[0048] <Processing flow> Next, the process flow of the kick motion detection method according to this embodiment will be described.

[0049] (Kick motion detection process) Fig. 9 is a flowchart showing an example of a kick motion detection process according to this embodiment. This process shows an example of a kick motion detection process executed by the control unit 102 of the kick sensor 100 having the functional configuration shown in Fig. 8 in the in-vehicle system 1 shown in Fig. 1, for example.

[0050] In step S901, the control unit 102 initializes the first distance x, the second distance y, the maximum amplitude A, and the counter count.

[0051] In step S902, the control unit 102 executes a feature extraction process to calculate a first distance x, a second distance y, a maximum amplitude A, and the like from the received signal output by the sensor unit 101. Note that the specific processing content of the feature extraction process will be described later.

[0052] In step S903, the control unit 102 determines whether the first distance x at which the object approaches the sensor unit 101 is within the first distance range described with reference to FIG. 4 (x min <x<x max If the first distance x is within the first distance range, the control unit 102 causes the process to proceed to step S904. On the other hand, if the first distance x is not within the first distance range, the control unit 102 returns the process to step S902.

[0053] In step S904, the control unit 102 determines whether the second distance by which the object is separated from the sensor unit 101 is within the second distance range (y min <y<y max If the second distance y is within the second distance range, the control unit 102 shifts the process to step S905. On the other hand, if the second distance y is not within the second distance range, the control unit 102 returns the process to step S902.

[0054] In step S905, the control unit 102 determines whether the maximum amplitude value A is equal to or greater than the predetermined value A Th Is it greater than or equal to (A Th ≦A) where A Th It is assumed that a threshold value for determining whether a received signal is noise or not is set in advance.

[0055] The maximum amplitude value A is the specified value A Th If the maximum amplitude value A is equal to or greater than the predetermined value A, the control unit 102 advances the process to step S906. Th If not, the control unit 102 determines that the received signal is noise, and returns the process to step S902.

[0056] Through the process of step S905, the control unit 102 can reduce the misdetection of the kick operation due to noise. For example, when the radio wave reflected by the ground is further reflected by an object and returns, or when the first distance x and the second distance y similar to the kick operation are detected by external radio waves such as the radar of another vehicle. On the other hand, most of the radio waves other than the radio wave directly reflected by the radio wave transmitted by the sensor unit 101 have a weak electric field strength. Therefore, through the process of step S905, the kick operation can be accurately determined based only on the radio wave directly reflected by the radio wave transmitted by the sensor unit 101.

[0057] In steps S906 and S907, the control unit 102 adds 1 to the counter count and determines whether the value of the counter count exceeds a predetermined value (count Th ), or (count Th < count). When the value of the counter count exceeds the predetermined value, the control unit 102 transfers the process to step S908. On the other hand, when the value of the counter count does not exceed the predetermined value, the control unit 102 returns the process to step S902.

[0058] Through the processes of steps S906 and S907, after the control unit 102 satisfies the condition that the first distance x is within the first distance range and the second distance y is within the second distance range, after a predetermined time has elapsed, it starts to determine the distance ratio between the first distance x and the second distance y.

[0059] If the determination is made immediately after the conditions that both the first distance x and the second distance y are within the predetermined range are satisfied, there is a problem that even if the target object moves at a high speed (so fast that it cannot be a kick operation) and finally y > y max occurs, it will be misjudged as a kick operation. Also, when moving while performing a kick operation (for example, moving backward immediately after the kick operation), the speed does not become 0 for a while even after the kick is completed. Therefore, if the determination is made based on the condition that the speed = 0, there is a problem that the determination will be delayed.

[0060] To solve the above two problems, the control unit 102 starts determining the distance ratio between the first distance x and the second distance y after a predetermined time has elapsed since the condition that the first distance x and the second distance y are within a predetermined range is satisfied. Also, the control unit 103 can make an early kick determination even for fast kicking motions by matching the predetermined time to a fast kicking motion. For example, the control unit 102 can accurately determine the kicking motion even for slow kicking motions by repeatedly making the determination after starting the determination.

[0061] In step S908, the control unit 102 determines whether the distance ratio, which is the ratio of the first distance x to the second distance y, is within a predetermined range. As one example, the control unit 102 determines whether the first distance ratio y / x, obtained by dividing the second distance y by the second distance x, is less than the first threshold value 501 described in FIG. 5. As another example, the control unit 102 determines whether the first distance ratio y / x is less than the first threshold value 501 and whether the first distance ratio x / y, obtained by dividing the first distance x by the second distance y, is less than the second threshold value 601 described in FIG. 6.

[0062] If the distance ratio, which is the ratio of the first distance x to the second distance y, is within the predetermined range, the control unit 102 shifts the process to step S909. On the other hand, if the distance ratio, which is the ratio of the first distance x to the second distance y, is not within the predetermined range, the control unit 102 returns the process to step S902.

[0063] In step S909, the control unit 102 determines that a kicking motion has been performed, outputs a detection result indicating that a kicking motion has been detected, for example, to the electronic control unit 12, and returns the process to step S901. For example, the electronic control unit 12 opens the back door 11 of the vehicle 10 based on the detection result output by the control unit 102.

[0064] By the process of FIG. 9, the kick sensor 100 can reduce the chance of mistakenly detecting a movement that is different from a kicking movement as a kicking movement.

[0065] (Feature extraction processing) Fig. 10 is a flowchart showing an example of feature extraction processing according to this embodiment. This processing shows an example of feature extraction processing executed by the control unit 102 of the kick sensor 100 in step S902 of Fig. 9. Note that here, the standby (S1) state described in Fig. 2 will be called "Idle," the approaching (S2) state will be called "Close," and the leaving (S3) state will be called "Leave."

[0066] In step S1001, the control unit 102 acquires the velocity v of the object and the amplitude a of the received signal from the received signal output by the sensor unit 101.

[0067] In step S1002, the control unit 102 determines whether Close (approach) or Leave (leave) has continued for T seconds. Here, it is assumed that the duration T for resetting the first distance x and the second distance y when the object continues to approach the sensor unit 101 or continues to move away from the sensor unit 101 is set in advance for T seconds. If the velocity v of the object is a positive value, the control unit 102 sets the Status to Close through processing described below. Also, if the velocity v of the object is a negative value, the control unit 102 sets the Status to Leave. In other words, the control unit 102 determines whether the duration of velocity v>0 exceeds T or the duration of velocity v<0 exceeds T.

[0068] If Close or Leave continues for T seconds, the control unit 102 shifts the process to step S1003. On the other hand, if Close or Leave does not continue for T seconds, the control unit 102 shifts the process to step S1004.

[0069] In step S1003, the control unit 102 initializes the values ​​of the first distance x, the second distance y, the maximum amplitude A, and the counter count. If the object continues to move at a speed that is too slow for a normal kicking motion, the control unit 102 determines that the kicking motion has not started, and by performing initialization, it is possible to reduce erroneous determination of the kicking motion by the control unit 102.

[0070] In step S1004, the control unit 102 determines whether the Status indicating the current state is Idle (standby). If the Status is Idle, the control unit 102 causes the process to proceed to step S1005. On the other hand, if the Status is not Idle, the control unit 102 causes the process to proceed to step S1010.

[0071] In step S1005, the control unit 102 determines whether the velocity v of the object is greater than 0 (whether v>0). If the velocity v is greater than 0, the control unit 102 causes the process to proceed to step S1006. On the other hand, if the velocity v is equal to or less than 0, the control unit 102 ends the process of FIG. 10.

[0072] In step S1006, the control unit 102 sets the Status indicating the current state to Close.

[0073] In step S1007, the control unit 102 updates the first distance x by multiplying the first distance x at which the object approaches the sensor unit 101 by (speed v)×(execution cycle t).

[0074] In steps S1008 and S1009, the control unit 102 determines whether the acquired amplitude a is greater than the maximum amplitude A, and if the amplitude a is greater than the maximum amplitude A, updates the maximum amplitude A to the value of the amplitude a.

[0075] On the other hand, when the process proceeds from step S1004 to step S1010, the control unit 102 determines whether the Status indicating the current state is Close (approaching). If the Status is Close, the control unit 102 proceeds to step S1011. On the other hand, if the Status is not Close, the control unit 102 proceeds to step S1014.

[0076] In step S1011, the control unit 102 determines whether the velocity v of the object is greater than 0 (v>0). If the velocity v is greater than 0, the control unit 102 causes the process to proceed to step S1007. On the other hand, if the velocity v is equal to or less than 0, the control unit 102 causes the process to proceed to step S1012.

[0077] In step S1007, the control unit 102 updates the first distance x by adding (speed v)×(execution cycle t) to the first distance x at which the object approaches the sensor unit 101.

[0078] In step S1012, the control unit 102 sets the Status indicating the current state to Leave.

[0079] In step S1013, the control unit 102 updates the second distance y by multiplying the second distance y, the distance the object has moved away from the sensor unit 101, by (speed v) × (execution cycle t), and proceeds to step S1008. In this embodiment, in step S1013, the second distance y is multiplied using a subtraction formula to make it a positive value. Even if the formula in S1013 is changed to y = y + vt, the same determination result can be obtained by changing the sign of the threshold value in the determination formula described below or the direction of the inequality sign.

[0080] On the other hand, when the process proceeds from step S1010 to S1014, the control unit 102 determines whether the velocity v of the object is less than 0 (whether v<0). At this time, the Status indicating the current state is neither Idle nor Close, so it becomes Leave. If the velocity v is less than 0, the control unit 102 proceeds to step S1013. In step S1013, the control unit 102 updates the second distance y by multiplying the second distance y, the distance the object is away from the sensor unit 101, by (velocity v)×(execution cycle t). On the other hand, if the velocity v is greater than or equal to 0, the control unit 102 proceeds to step S1015.

[0081] In step S1015, the control unit 102 sets the Status indicating the current state to Idle. In step S1016, the control unit 102 initializes the first distance x, the second distance y, the maximum amplitude A, and the counter count, and then the process returns to step S1005.

[0082] 10, the control unit 102 of the kick sensor 100 can calculate the first distance x, the second distance y, the maximum amplitude A, and the like from the received signal output by the sensor unit 101.

[0083] (Distance ratio determination process) Here, we will explain variations of the distance ratio determination process in step S908 of Figure 9, in which the control unit 102 of the kick sensor 100 determines whether the distance ratio between the first distance x and the second distance y is within a predetermined range.

[0084] As an example, in step S908 of FIG. 9, as shown in FIG. 11A, the control unit 102 determines whether the first distance ratio y / x obtained by dividing the second distance y by the first distance x is equal to or greater than the first threshold ratio described with reference to FIG. Th It is determined whether the first distance ratio y / x is less than 1. Th If the ratio is less than 1, the control unit 102 determines that the distance ratio between the first distance x and the second distance is within a predetermined range, and moves the process to step S909. Th If it is not less than 1, the control unit 102 determines that the distance ratio between the first distance x and the second distance is not within a predetermined range, and returns the process to step S902. By this process, the control unit 102 can determine that the motion is not a kicking motion when the second distance y is excessively large compared to the first distance x.

[0085] As another example, the control unit 102 may execute the processes of steps S908a and S908b as shown in Fig. 11B in step S908 of Fig. 9. In step S908a, the control unit 102 determines whether the first distance ratio y / x is equal to or smaller than the first threshold ratio described in Fig. 5.Th It is determined whether the first distance ratio y / x is less than 1. Th If the first distance ratio y / x is less than 1, the control unit 102 shifts the process to step S908b. Th If it is not less than 1, the control unit 102 returns the process to step S902.

[0086] In step S908b, the control unit 102 determines whether the second distance ratio x / y obtained by dividing the first distance x by the second distance y is equal to or greater than the second threshold ratio described with reference to FIG. Th 2. Determine whether the second distance ratio x / y is less than the second threshold ratio Th If the ratio is less than 2, the control unit 102 determines that the distance ratio between the first distance x and the second distance is within a predetermined range, and moves the process to step S909. Th If it is not less than 2, the control unit 102 determines that the distance ratio between the first distance x and the second distance is not within a predetermined range, and returns the process to step S902. By this process, the control unit 102 can determine that the motion is not a kicking motion even when the first distance x is excessively large compared to the second distance y.

[0087] In addition, in the kick sensor 100, which is designed to assume that the user performs a kicking motion while approaching, it is considered that the position where the leg is returned will be closer to the kick sensor 100 than the position before the leg is kicked up. In this case, the first threshold ratio Th 1 is the second threshold ratio Th Preferably less than 2.

[0088] On the other hand, in the kick sensor 100 that is designed to assume that the user will perform a kicking motion after stopping, the position of the leg before kicking up and the position of the leg after returning to the starting position generally coincide with each other. Th 1 and the second threshold ratio Th It is desirable to make 2 equal.

[0089] Furthermore, in the kick sensor 100 for opening the back door of the vehicle, the user moves back after performing a kick motion, so the first threshold ratio Th 1 is the second threshold ratio Th Preferably greater than 2.

[0090] 11C shows a modification of the process of FIG. 11A. For example, as shown in FIG. 11C, the control unit 102 calculates a first threshold ratio Th By comparing the magnitude relationship between x times 1 and the second distance y, the first distance ratio y / x is substantially determined to be equal to or smaller than the first threshold ratio Th It may be a method for determining whether the value is less than 1.

[0091] Similarly, Fig. 11D shows a modification of the process of Fig. 11B. For example, instead of calculating x / y as shown in Fig. 11D, the control unit 102 calculates a second threshold ratio Th By comparing y times 2 with the first distance x, the second distance ratio x / y is substantially equal to or smaller than the second threshold ratio Th It may be a method for determining whether the number of times the number of times is less than 2.

[0092] Furthermore, the control unit 102 determines the first threshold ratio Th 1 and the second threshold ratio Th 2, as shown in FIG. 11E, it may be determined whether the distance ratio of the first distance x to the second distance y is within a predetermined range by the following (Equation 1).

[0093]

number

[0094] In this case, the control unit 102 determines that a kicking motion has been performed if the distance ratio is equal to or greater than the threshold value. Note that the y / x<constant and the x / y> constant are synonymous, and the x / y<constant and the y / x> constant are synonymous (although the values ​​of the respective constants are different).

[0095] Alternatively, as shown in FIG. 11F, the control unit 102 may determine whether the distance ratio between the first distance x and the second distance y is within a predetermined range using the following (Equation 2).

[0096]

number

[0097] In this way, when determining whether the distance ratio between the first distance x and the second distance y is within a predetermined range in step S908 of FIG. 9, the control unit 102 does not necessarily have to calculate the first distance ratio y / x or the second distance ratio x / y.

[0098] As described above, according to the embodiment of the present invention, it is possible to reduce the chance of a kick sensor that detects a kicking motion by a user erroneously detecting a motion that is different from a kicking motion as a kicking motion.

[0099] Furthermore, the vehicle 10 equipped with the kick sensor 100 according to this embodiment can reduce the risk of the doors of the vehicle 10 being opened or closed erroneously in response to an action other than a kick action.

[0100] This application claims priority from basic application No. 2023-023904, filed with the Japan Patent Office on February 20, 2023, the entire contents of which are incorporated herein by reference.

[0101] The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0102] 1. In-vehicle systems 2. Legs (example of target object) 10 vehicles 11 Backdoor 12 Electronic Control Unit (ECU) 100 Kick Sensor 101 Sensor unit 102 Control section 501 First Threshold 601 Second Threshold 700 computers

Claims

1. a sensor unit provided in the vehicle and configured to detect approach and departure of an object; a control unit that determines the movement of the object based on the detection result of the sensor unit; Equipped with The control unit calculating a first distance by which the object approaches the sensor unit and a second distance by which the object moves away from the sensor unit; determining that a kicking motion has been performed when the first distance is within a first distance range, the second distance is within a second distance range, and a first distance ratio obtained by dividing the second distance by the first distance is less than a first threshold value; Kick sensor.

2. 2. The kick sensor according to claim 1, wherein the control unit starts determining the first distance ratio after a predetermined time has elapsed since the first distance is within the first distance range and the second distance is within the second distance range.

3. the sensor unit transmits a signal and measures the amplitude of a received signal that is reflected by the object; The control unit storing a maximum amplitude value of the received signal received from the start of measurement of the first distance until the end of measurement of the second distance; If the maximum amplitude value is less than a predetermined value, it is determined that the kicking motion is not being performed. The kick sensor according to claim 1 .

4. the sensor unit includes a Doppler radar, The control unit calculating the first distance by accumulating the velocity of the object while it is approaching the sensor unit; and calculating the second distance by accumulating the velocity of the object while it is away from the sensor unit. The kick sensor according to claim 1 .

5. The control unit determining that a kicking motion has been performed when the first distance is within a first distance range, the second distance is within a second distance range, and a second distance ratio obtained by dividing the first distance by the second distance is less than a second threshold value; The kick sensor according to claim 1 .

6. The kick sensor of claim 5 , wherein the first threshold value is less than the second threshold value.

7. The kick sensor of claim 5 , wherein the first threshold value and the second threshold value are equal.

8. The kick sensor of claim 5 , wherein the first threshold value is greater than the second threshold value.

9. The kick sensor according to claim 1 , wherein a lower limit value of the first distance range is smaller than a lower limit value of the second distance range.

10. The kick sensor according to claim 1 , wherein an upper limit value of the first distance range is greater than an upper limit value of the second distance range.

11. The control unit measuring a duration during which the object continues to approach the sensor unit or continues to move away from the sensor unit; resetting the first distance and the second distance if the duration exceeds a predetermined time; The kick sensor according to claim 1 .

12. A vehicle comprising the kick sensor according to any one of claims 1 to 4.

13. a sensor unit provided in the vehicle and configured to detect approach and departure of an object; a control unit that determines the movement of the object based on the detection result of the sensor unit; A method for detecting a kicking motion using a kick sensor comprising: The control unit calculating a first distance by which the object approaches the sensor unit and a second distance by which the object moves away from the sensor unit; determining that a kicking motion has been performed when the first distance is within a first distance range, the second distance is within a second distance range, and a first distance ratio obtained by dividing the second distance by the first distance is less than a first threshold value; How to detect kicking motion.

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