Sudden acceleration / deceleration determination device and sudden acceleration / deceleration determination method

Abstract

To provide a sudden acceleration / deceleration determination device and a sudden acceleration / deceleration determination method for a vehicle that is less susceptible to the effects of a loading condition of a vehicle than conventional methods.SOLUTION: A sudden acceleration / deceleration determination device 1 mounted on a vehicle 21 includes: a first determination unit 3 that determines the vehicle 21 has undergone sudden acceleration / deceleration when the acceleration detected by an acceleration sensor 15, which detects the acceleration of the vehicle 21, exceeds a predetermined acceleration threshold and continues for a time equal to or longer than a predetermined time threshold; an image recognition unit 5 that determines whether the vehicle 21 is carrying a load; and a threshold setting unit 7 that sets the time threshold to a longer value when the image recognition unit 5 determines that a load is being carried than when it determines that no load is being carried.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sudden acceleration / deceleration determination device and a sudden acceleration / deceleration determination method. [Background technology]

[0002] Some vehicle-mounted devices, such as drive recorders, may determine that a collision accident or dangerous driving has occurred when a vehicle on which they are mounted suddenly accelerates or decelerates, and record the time of the sudden acceleration or deceleration, or issue an alarm. One method for determining whether a vehicle has suddenly accelerated or decelerated is to determine that the vehicle has suddenly accelerated or decelerated when the acceleration detected by an acceleration sensor mounted on the vehicle exceeds an acceleration threshold. On the other hand, even if the vehicle has not suddenly accelerated or decelerated, the acceleration value detected by the acceleration sensor may be high when the vehicle has gone over a step, such as an uneven road surface. Therefore, when determining whether a vehicle has suddenly accelerated or decelerated from the acceleration detected by the acceleration sensor, it is necessary to avoid misjudging that the vehicle has gone over a step as a sudden acceleration or deceleration. Specifically, it is necessary to distinguish between actual sudden acceleration and deceleration of the vehicle and actual going over a step from the acceleration values ​​detected by the acceleration sensor, and to remove the acceleration value when the step has been gone over as noise. One method for eliminating noise from acceleration values ​​when a step is crossed is to use the time it takes for the acceleration detected by an acceleration sensor to exceed an acceleration threshold. This is because the time it takes for the acceleration sensor's detection value to exceed the acceleration threshold when the vehicle crosses a step is shorter than the time when the vehicle actually accelerates or decelerates suddenly. Therefore, it is sometimes determined that the vehicle actually accelerated or decelerated suddenly only when the state in which the detected acceleration exceeds the acceleration threshold continues for a time threshold or more, and that if the state continues for less than the time threshold, it is determined that the vehicle crossed a step but did not accelerate or decelerate suddenly (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-62234 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the time during which the acceleration sensor detection value exceeds the acceleration threshold when going over a step becomes longer as the vehicle weight becomes heavier, when the vehicle is loaded, the vehicle weight becomes heavier than when it is not loaded, and the state in which the acceleration exceeds the acceleration threshold when going over a step continues for a longer period of time. Therefore, when the vehicle is loaded, even when going over a step, the time during which the acceleration sensor detection value exceeds the acceleration threshold may continue for more than the time threshold, which may lead to an erroneous determination that the vehicle has suddenly accelerated or decelerated.

[0005] The present invention has been made to solve such problems, and its object is to provide a sudden acceleration / deceleration determination device and a sudden acceleration / deceleration determination method that are less affected by the loading state of the vehicle than conventional devices. [Means for solving the problem]

[0006] The sudden acceleration / deceleration judgment device of the present invention is a sudden acceleration / deceleration judgment device that is loaded on the vehicle and includes a first judgment unit that judges that the vehicle has suddenly accelerated or decelerated when the acceleration detected by an acceleration sensor that detects the acceleration of the vehicle exceeds a predetermined acceleration threshold and continues to exceed a predetermined time threshold, and further includes a second judgment unit that judges whether the vehicle is carrying cargo, and a threshold setting unit that, when the second judgment unit determines that the vehicle is carrying cargo, sets the time threshold to a longer value than when it is determined that the vehicle is not carrying cargo.

[0007] The sudden acceleration / deceleration determination method of the present invention includes a detection step of detecting the acceleration of a vehicle using an acceleration sensor, and a first determination step of determining that the vehicle has suddenly accelerated or decelerated if the acceleration detected by the acceleration sensor exceeds a predetermined acceleration threshold and continues for a period of time equal to or longer than a predetermined time threshold, and further includes a second determination step of determining whether the vehicle is carrying cargo, and a threshold setting step of setting the time threshold to a longer value than when it is determined that the vehicle is not carrying cargo in the second determination step. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a sudden acceleration / deceleration determination device and a sudden acceleration / deceleration determination method that are less susceptible to the influence of the loading state of a vehicle than conventional devices. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram showing a sudden acceleration / deceleration determination device according to an embodiment of the present invention; [Figure 2] 10A and 10B are diagrams showing the relationship between acceleration detected by an acceleration sensor and time, in which (a) shows a case where an unladen vehicle suddenly accelerates or decelerates, (b) shows a case where an unladen vehicle goes over a bump in the road surface, and (c) shows a case where a laden vehicle goes over a bump in the road surface. [Figure 3] 3 is a flowchart showing the procedure of a sudden acceleration / deceleration determination method using the sudden acceleration / deceleration determination device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below in accordance with preferred embodiments. Note that the present invention is not limited to the embodiments shown below and can be modified as appropriate without departing from the spirit of the present invention. In addition, in the embodiments shown below, some components are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are applied as appropriate to the details of the omitted technologies within the scope of the content described below.

[0011] First, with reference to FIGS. 1 and 2, an outline of the configuration of a sudden acceleration / deceleration determination device according to an embodiment of the present invention will be described. FIG. 1 is a configuration diagram showing a sudden acceleration / deceleration determination device according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between acceleration detected by an acceleration sensor and time. Specifically, (a) shows a case where an unladen vehicle suddenly accelerates or decelerates, (b) shows a case where an unladen vehicle goes over a step in the road surface, and (c) shows a case where a loaded vehicle goes over a step in the road surface. Note that in the embodiment of the present invention, a vehicle that transports cargo, such as a forklift, is exemplified as a vehicle for which the sudden acceleration / deceleration determination device determines sudden acceleration / deceleration. The sudden acceleration / deceleration determination device 1 shown in FIG. 1 is mounted on a vehicle 21, which is the vehicle itself, and includes a first determination unit 3, an image recognition unit 5 (second determination unit), and a threshold setting unit 7. The sudden acceleration / deceleration determination device 1 also includes an alarm unit 9, a recording unit 11, and a clock 13.

[0012] The first determination unit 3 determines whether the vehicle 21 has suddenly accelerated or decelerated, and is connected to the acceleration sensor 15, to which a signal indicating the acceleration detected by the acceleration sensor 15 is input. The acceleration sensor 15 is a sensor that detects the acceleration in the longitudinal direction of the vehicle 21, and may be of a known type such as a capacitance type or a strain gauge type. The acceleration sensor 15 may be a two-axis sensor that detects acceleration in the longitudinal direction and the lateral direction, or a three-axis sensor that detects acceleration in the longitudinal direction, lateral direction, and up and down direction. Although the acceleration sensor 15 shown in FIG. 1 is provided external to the sudden acceleration / deceleration determination device 1, the sudden acceleration / deceleration determination device 1 may have the acceleration sensor 15 built in.

[0013] The first determination unit 3 determines whether the vehicle 21 has suddenly accelerated or decelerated in the following manner. For example, when the vehicle 21 suddenly accelerates or decelerates at time t0 shown in FIG. 2(a), the acceleration (here, acceleration means an absolute value; the same applies hereinafter) detected by the acceleration sensor 15 increases, then decreases, and reaches time t E At this time, the first determination unit 3 determines whether the state in which the acceleration detected by the acceleration sensor 15 exceeds the predetermined acceleration threshold a1 continues for a predetermined time threshold T A If the acceleration continues for the above period, it is determined that the vehicle 21 has suddenly accelerated or decelerated. For example, in FIG. 2(a), the state in which the acceleration detected by the acceleration sensor 15 exceeds the acceleration threshold a1 continues for the period T1, but the period T1 is shorter than the period T2. A For the above reasons, the first determination unit 3 determines that the vehicle 21 has suddenly accelerated or decelerated. On the other hand, as shown in FIG. 2(b), when the vehicle 21 goes over a step such as an uneven road surface while traveling, the vehicle 21 accelerates and decelerates not only in the vertical direction but also in the longitudinal direction. Therefore, the acceleration detected by the acceleration sensor 15 may increase and exceed the acceleration threshold value a1. In particular, when the vehicle 21 is a forklift, the vehicle height relative to the wheelbase is higher than that of a passenger car and the like, and the vehicle 21 does not have a suspension, so the vehicle 21 is likely to accelerate or decelerate in the longitudinal direction when going over a step. Furthermore, the sudden acceleration / deceleration determination device 1 is expected to be used as part of the function of an in-vehicle device such as a drive recorder, and drive recorders tend to be installed at a high position on the vehicle 21. Therefore, when the acceleration sensor 15 is built in, the detected value of the longitudinal acceleration is likely to be large. On the other hand, as shown in FIG. 2(b), the time T2 at which the detected value of the acceleration sensor 15 exceeds the acceleration threshold value a1 when going over a step is shorter than the time T1 at which the detected value exceeds the acceleration threshold value a1 when the vehicle 21 actually suddenly accelerates or decelerates. Therefore, the time threshold value T A is set in advance to a time longer than time T2 and shorter than time T1, the time during which the detected value of the acceleration sensor 15 exceeds the acceleration threshold value a1 will be the time threshold value T AThis is the end. Therefore, it is possible to determine whether the vehicle 21 has suddenly accelerated or decelerated by removing the fluctuation in acceleration caused by going over a step as noise. Furthermore, since the acceleration detected by the acceleration sensor 15 only needs to be the acceleration in the forward / backward direction, even if the acceleration sensor 15 is a two-axis sensor that cannot detect acceleration in the up / down direction, it is possible to remove the fluctuation in the detected value of the acceleration sensor 15 caused by the fluctuation in acceleration in the up / down direction caused by going over a step as noise. Therefore, the sudden acceleration / deceleration determination device 1 can remove the fluctuation in acceleration that occurs when going over a step as noise even if the acceleration sensor 15 is not a three-axis sensor.

[0014] The image recognition unit 5 determines whether the vehicle 21 is carrying a load. In FIG. 1, the image recognition unit 5 is connected to an on-board camera 17, and receives an image captured by the camera 17. The camera 17 is an imaging device that captures an image of a loading section (not shown) on which the vehicle 21 carries a load. If the vehicle 21 is a forklift, the loading section is a fork. The image recognition unit 5 determines whether a load is present in the image captured by the camera 17 based on the results of machine learning or a known image analysis technique such as edge extraction. If the image determines that a load is present, the image recognition unit 5 determines that the vehicle is carrying a load. If the image does not contain a load, the image recognition unit 5 determines that the vehicle is not carrying a load. If the vehicle is carrying a load, the image recognition unit 5 may also determine the size and height of the load as needed. In this way, by determining whether a load is present from an image of the loading section, the camera 17 already installed in the vehicle 21 can be used. However, the means for determining whether the vehicle 21 is carrying a load is not limited to a means for determining from an image. For example, the vehicle weight may be measured using a sensor or the like to measure the vehicle weight and compared with the weight when the vehicle is not loaded, and if the measured vehicle weight is greater, it may be determined that the vehicle is loaded. Alternatively, a sensor such as a strain gauge may be provided on the axle of the vehicle 21, and the presence or absence of a load may be determined by comparing the detected value with the value when the vehicle is not loaded. The timing at which the image recognition unit 5 determines whether the vehicle 21 is loaded may be synchronized with, for example, the timing at which the camera 17 captures an image of the loading area.

[0015] The threshold setting unit 7 sets the time threshold T AThe threshold setting unit 7 is connected to the image recognition unit 5, and receives the result of the determination by the image recognition unit 5 as to whether or not a cargo is loaded. Specifically, when the image recognition unit 5 determines that a cargo is loaded, the threshold setting unit 7 sets the time threshold T A Set to a long value and set the time threshold T A to the first determination unit 3. More specifically, the threshold setting unit 7 sets the time threshold T A1 and the time threshold T A2 Furthermore, when the image recognition unit 5 determines that no cargo is loaded, the threshold setting unit 7 sets the time threshold T A time threshold T A1 , and if it is determined that a cargo is loaded, the time threshold T A time threshold T A2 The reason is as follows: The sudden acceleration / deceleration determination device 1 determines whether the time during which the detected value of the acceleration sensor 15 exceeds the acceleration threshold value a1 continues to be equal to the time threshold value T A If the difference is less than 1 / 2, it is determined that a step has been crossed, and it is not determined that the vehicle 21 has suddenly accelerated or decelerated. On the other hand, the time period during which the detection value of the acceleration sensor 15 is high when a step has been crossed becomes longer as the vehicle weight becomes heavier. Therefore, as shown in FIG. 2(c), when the vehicle 21 is loaded, the vehicle weight is heavier than when it is not loaded, and therefore the time T3 during which the detection value of the acceleration sensor 15 continues to exceed the acceleration threshold value a1 when a step has been crossed is equal to or longer than the time threshold value T A1 In this case, the first determination unit 3 may erroneously determine that the vehicle 21 has suddenly accelerated or decelerated. Therefore, the threshold value setting unit 7 sets the time threshold value T A2 , the time threshold T A1 For example, if the weight of a loaded vehicle is 1.5 times that of an unloaded vehicle, the time threshold T A2 time threshold T A1 More specifically, the time threshold T A2is longer than the time T3 during which the detected value of the acceleration sensor 15 exceeds the acceleration threshold a1 when the loaded vehicle 21 hits a step. A2 is shorter than the time during which the detected value of the acceleration sensor 15 exceeds the acceleration threshold value a1 when the loaded vehicle 21 suddenly accelerates or decelerates. A1 , T A2 The timing for setting the time threshold T is when the result of the determination by the image recognition unit 5 as to whether or not a cargo is loaded is input. When the determination result is input, the time threshold T A1 , T A2 The above configuration may be adopted.

[0016] In this way, the threshold setting unit 7 sets the time threshold T A Therefore, the sudden acceleration / deceleration determination device 1 can reduce the possibility of erroneously determining that the vehicle 21 has suddenly accelerated or decelerated, even when the vehicle 21 is loaded and the high acceleration state continues for a long time after going over a step. Therefore, the sudden acceleration / deceleration determination device 1 can be less susceptible to the influence of the loading state of the vehicle 21 when determining sudden acceleration / deceleration than before.

[0017] The threshold setting unit 7 sets the time threshold T A , the time threshold T when the vehicle 21 is not loaded A1 and the time threshold T A2 and at least two time thresholds T A However, when the image recognition unit 5 determines that a load is present, the threshold value setting unit 7 sets the time threshold value T A2 For example, the threshold value setting unit 7 may set the time threshold value T A2 The time threshold T A2 In this configuration, the sudden acceleration / deceleration determination device 1 sets the time threshold value T A2Therefore, when the load of cargo is heavy and the state in which the acceleration is high when going over a step continues for a long time, the time threshold T A2 The time period is longer, and the accuracy of determining sudden acceleration / deceleration is further improved. Whether the load is large or small can be determined by the image recognition unit 5 acquiring information indicating the size and height of the loaded cargo and transmitting it to the threshold setting unit 7, which then determines from the received information.

[0018] Also, the time threshold T A1 , T A2 The time threshold T can be calculated from past data showing the relationship between time and acceleration when the vehicle 21 suddenly accelerates or decelerates or goes over a step when it is loaded and when it is not loaded. A1 , T A2 varies depending on the model and type of vehicle. For example, if the vehicle 21 is a forklift, there are different models such as reach lifts and counter lifts, and even if the model is the same, there are differences in the model that indicate differences in the manufacturer, maximum load capacity, etc. On the other hand, if the model and model are different, the overall length of the vehicle 21, the type of cargo to be loaded, and the maximum load capacity will differ, so the time threshold T A1 , T A2 The time threshold T 1 also differs depending on whether the vehicle 21 is a forklift or a heavy machine. A1 , T A2 It is preferable to store the time threshold T in advance in the threshold setting unit 7. A1 , T A2 In order to store the time threshold T A1 , T A2 On the other hand, as shown in FIG. 1, the server 33 and the user PC 31 may be used to input the time threshold T A1 , T A2 Alternatively, the time threshold T may be set by operating the mobile terminal 35 using the mobile terminal 35, the user PC 31, and the server 33. A1 , T A2For example, when the server 33 manages the operation of a plurality of vehicles 21 equipped with the sudden acceleration / deceleration determination device 1 using a communication technology such as OTA (Over The Air), operation information such as the time t0 at which the vehicle 21 suddenly accelerates or decelerates is accumulated in the server 33. This allows the server 33 to monitor, from the accumulated operation information, whether each vehicle 21 has caused a collision accident or is driving recklessly. In such a configuration, the time threshold T A1 , T A2 is stored in advance in the threshold setting unit 7, the time threshold T A1 , T A2 You can set the following.

[0019] The server 33 shown in FIG. A1 , T A2 The time threshold T A1 , T A2 The server 33 is a computer that stores the time threshold T A1 , T A2 The threshold processing unit 33b is a program for storing, for example, a time threshold T A1 , T A2 Here, the time threshold T A1 , T A2 from the user PC 31 and transmits it to the threshold setting unit 7. The threshold processing unit 33b sets the time threshold T A1 , T A2 The user PC 31 is a computer connected to the server 33 via the Internet communication network 34, and includes a setting operation unit 31a. The setting operation unit 31a is used to set, for example, the time threshold T A1 , TA2 The setting operation unit 31a is a program for setting the time threshold T A1 , T A2 When setting the time threshold T A1 , T A2 The list is displayed on a monitor (not shown) or the like, and the user (operation manager of the vehicle 21) who operates the user PC 31 selects the time threshold T A1 , T A2 is transmitted to and stored in the threshold setting unit 7 of the sudden acceleration / deceleration determination device 1 via the server 33. In this manner, in Fig. 1, the user PC 31 and the sudden acceleration / deceleration determination device 1 are connected via the server 33. Here, the operation management system including the server 33, the user PC 31, and the sudden acceleration / deceleration determination device 1 is also referred to as a sudden acceleration / deceleration determination system 100.

[0020] The mobile terminal 35 shown in Fig. 1 is, for example, a tablet terminal or a smartphone. The mobile terminal 35 can communicate with the user PC 31 via the Internet communication network 34, but cannot communicate with the server 33. In other words, the mobile terminal 35 is a terminal that is external to the sudden acceleration / deceleration determination system 100, which is an operation management system. The mobile terminal 35 has a setting processing unit 35a and a threshold processing unit 33b. The setting processing unit 35a is, for example, a unit that sets a time threshold T A1 , T A2 However, since the mobile terminal 35 cannot directly communicate with the server 33, it does not, like the user PC 31, transmit the time threshold T A1 , T A2 Therefore, the mobile terminal 35 downloads the threshold processing unit 33b from the server 33 via the user PC 31, and calculates the time threshold T A1 , T A2 and directly inputs the time threshold T A1 , T A2 Furthermore, the mobile terminal 35 transmits the time threshold T A1 , TA2 Therefore, the user PC 31 has a download processing unit 31b, which is a program that downloads a threshold processing unit 33b from the server 33 in response to a request from the mobile terminal 35 and transmits the downloaded threshold processing unit 33b to the mobile terminal 35. The user PC 31 and the mobile terminal 35 are configured to set the time threshold T A1 , T A2 In addition, the acceleration threshold value a1 may be set.

[0021] The alarm unit 9 shown in FIG. 1 is provided as needed to issue an alarm to the driver of the vehicle 21 when the first determination unit 3 determines that the vehicle 21 has suddenly accelerated or decelerated, and receives the determination result of the first determination unit 3. Specifically, when the determination result of the first determination unit 3 that the vehicle 21 has suddenly accelerated or decelerated is received as input to the alarm unit 9, the alarm unit 9 displays a warning in the form of text or graphics on a monitor 19 mounted on the vehicle 21 and / or emits an alarm sound from a speaker 23 mounted on the vehicle 21. When the first determination unit 3 determines that the vehicle 21 has suddenly accelerated or decelerated, the recording unit 11 records the fact that the vehicle 21 has suddenly accelerated or decelerated, and receives the determination result of the first determination unit 3. Specifically, when the determination result of the first determination unit 3 that the vehicle 21 has suddenly accelerated or decelerated is received as input to the alarm unit 9, the alarm unit 9 records information indicating the time, location, etc. of the sudden acceleration / deceleration of the vehicle 21 in a memory unit (not shown) of the sudden acceleration / deceleration determination device 1. The clock 13 is used to identify the time when the vehicle 21 suddenly accelerates or decelerates, and is connected to the recording unit 11. When the first determination unit 3 determines that the vehicle 21 suddenly accelerates or decelerates, the recording unit 11 acquires information indicating the time when the vehicle 21 suddenly accelerates or decelerates from the clock 13 and stores the information in the memory unit. In addition, as necessary, the recording unit 11 transmits information indicating the time, location, etc. when the vehicle 21 suddenly accelerates or decelerates to the server 33.

[0022] The sudden acceleration / deceleration determination device 1 may be realized by storing programs that realize the first determination unit 3, image recognition unit 5, threshold setting unit 7, alarm unit 9, recording unit 11, and clock 13 in a memory unit of a general-purpose computer and having the central processing unit of the general-purpose computer execute each program. On the other hand, the sudden acceleration / deceleration determination device 1 may be a dedicated machine that includes devices and circuits that realize the first determination unit 3, image recognition unit 5, threshold setting unit 7, alarm unit 9, recording unit 11, and clock 13. This completes the description of the outline of the configuration of the sudden acceleration / deceleration determination device 1.

[0023] Next, the procedure of the sudden acceleration / deceleration determination method using the sudden acceleration / deceleration determination device 1 will be described with reference to FIG. A1 , T A2 is set in advance in the threshold setting unit 7 (S0 in FIG. 3). In this case, first, the image recognition unit 5 acquires an image of the loading section of the vehicle 21 from the camera 17 (S1 in FIG. 3). Next, the image recognition unit 5 determines whether the vehicle 21 is loaded with cargo from the acquired image, and if it determines that the vehicle 21 is loaded with cargo, the process proceeds to S3, and if it determines that the vehicle 21 is not loaded with cargo, the process proceeds to S4 (S2 in FIG. 3, second determination step). If the image recognition unit 5 determines that the vehicle 21 is loaded with cargo in S2, the image recognition unit 5 transmits the determination result that the vehicle 21 is loaded with cargo to the threshold setting unit 7, and the threshold setting unit 7 sets the time threshold T A , the time threshold T A2 and proceed to S5 (S3 in FIG. 3, threshold setting step). If the image recognition unit 5 determines that no cargo is loaded in S2, the image recognition unit 5 transmits the determination result that no cargo is loaded to the threshold setting unit 7. The threshold setting unit 7 sets the time threshold T A , the time threshold T A1 and proceed to S5 (S4 in FIG. 3, threshold setting step). That is, in the threshold setting step, when the image recognition unit 5 determines in S2 that the vehicle 21 is loaded with cargo, the threshold setting unit 7 sets the time threshold T A to a long value. Next, the first determination unit 3 detects the acceleration of the vehicle 21 by acquiring the acceleration detected by the acceleration sensor 15 (S5 in FIG. 3, detection step).

[0024] Next, the first determination unit 3 determines whether the acceleration detected by the acceleration sensor 15 exceeds the acceleration threshold value a1. If it is determined that the acceleration has exceeded the acceleration threshold value a1, the first determination unit 3 proceeds to S7. If it is determined that the acceleration detected by the acceleration sensor 15 has exceeded the acceleration threshold value a1, the first determination unit 3 determines whether the state in which the acceleration has exceeded the acceleration threshold value a1 continues for a period of time longer than the time threshold value T A If it is determined that the acceleration has continued, the process proceeds to S9. If it is determined that the acceleration has not continued, the process proceeds to S8 (S7 in FIG. 3, first determination step). The state in which the acceleration has exceeded the acceleration threshold a1 in S7 is determined as the time threshold T A If it is determined that the above has continued, the first determination unit 3 determines that the vehicle 21 has suddenly accelerated or decelerated, and proceeds to S10 (S9 in FIG. 3, first determination step). If the first determination unit 3 determines in S9 that the vehicle 21 has suddenly accelerated or decelerated, the first determination unit 3 transmits the determination result to the alarm unit 9 and the recording unit 11. The alarm unit 9, having received the determination result, issues an alarm using the monitor 19 or speaker 23, and the recording unit 11, having received the determination result, records the fact that the vehicle 21 has suddenly accelerated or decelerated, as well as the time, etc. (S10 in FIG. 3). If it is determined in S6 that the acceleration does not exceed the acceleration threshold a1, the first determination unit 3 determines that the vehicle 21 has not suddenly accelerated or decelerated, and returns (S8 in FIG. 3). In this case, the vehicle 21 has not suddenly accelerated or decelerated, and has not crossed a step. Furthermore, if the state in S7 in which the acceleration has exceeded the acceleration threshold a1 is determined to be within the time threshold T A If it is determined that the sudden acceleration / deceleration is not continuing, the first determination unit 3 determines that the vehicle 21 is not suddenly accelerating or decelerating, and returns (S8 in FIG. 3). In this case, the vehicle 21 has gone over a step, but has not suddenly accelerated or decelerated. This concludes the description of the procedure for the sudden acceleration / deceleration determination method using the sudden acceleration / deceleration determination device 1.

[0025] In this way, the sudden acceleration / deceleration determination device 1 of this embodiment determines whether the state in which the detected value of the acceleration sensor 15 exceeds the acceleration threshold value a1 is within the time threshold value T A The sudden acceleration / deceleration determination device 1 includes a first determination unit 3 that determines that the vehicle 21 has suddenly accelerated or decelerated if the above-mentioned state continues. The sudden acceleration / deceleration determination device 1 also includes an image recognition unit 5 that determines whether the vehicle 21 is loaded with cargo, and if the image recognition unit 5 determines that the vehicle 21 is loaded with cargo, determines that the time threshold TA In this configuration, the state in which the detected value of the acceleration sensor 15 exceeds the acceleration threshold value a1 is equal to the time threshold value T A When the vehicle 21 is judged to have suddenly accelerated or decelerated if the vehicle 21 has been loaded with a load, the time threshold T A Therefore, the sudden acceleration / deceleration determination device 1 can reduce the possibility of erroneously determining that the vehicle 21 has suddenly accelerated or decelerated, even when the vehicle 21 is loaded and the high acceleration state continues for a long time after going over a step. Therefore, the sudden acceleration / deceleration determination device 1 is less susceptible to the influence of the loading state of the vehicle 21 when determining sudden acceleration / deceleration than conventional devices.

[0026] In addition, when the image recognition unit 5 determines that the vehicle 21 is loaded with cargo, the threshold value setting unit 7 of the sudden acceleration / deceleration determination device 1 of this embodiment sets the time threshold value T A In this configuration, the sudden acceleration / deceleration determination device 1 increases the time threshold value T A Therefore, when the load of cargo is heavy and the state in which the acceleration is high when going over a step continues for a long time, the time threshold T A This increases the accuracy of determining sudden acceleration / deceleration.

[0027] Furthermore, the image recognition unit 5 of the sudden acceleration / deceleration determination device 1 of this embodiment determines whether the vehicle 21 is carrying cargo from an image of the loading section where the cargo is carried. In this configuration, if cargo is visible in the image, it is determined that cargo is carried, and if not, it is determined that no cargo is carried. Therefore, the camera 17 already installed in the vehicle 21 can be used, and a sensor for measuring vehicle weight or the like is not required.

[0028] On the other hand, the sudden acceleration / deceleration determination method of this embodiment includes a detection step of detecting the acceleration of the vehicle 21, and a time threshold T AThe method for determining sudden acceleration / deceleration of the present embodiment further includes a first determination step of determining that the vehicle 21 has suddenly accelerated or decelerated if the sudden acceleration / deceleration continues for the above period of time. The method also includes a second determination step of determining whether the vehicle 21 is loaded with cargo, and a second determination step of determining that the vehicle 21 is loaded with cargo if the second determination step determines that the vehicle 21 is loaded with cargo, and a second determination step of determining that the vehicle 21 is loaded with cargo if the second determination step determines that the vehicle 21 is not loaded with cargo. A In this configuration, the state in which the detected acceleration exceeds the acceleration threshold a1 is determined as the time threshold T A When the vehicle 21 is judged to have suddenly accelerated or decelerated if the vehicle 21 has been loaded with a load, the time threshold T A Therefore, even if the vehicle 21 is loaded and a high acceleration state continues for a long time when the vehicle goes over a step, the possibility of erroneously determining that the vehicle 21 has suddenly accelerated or decelerated can be reduced, and the sudden acceleration or deceleration determination is less susceptible to the influence of the loading state of the vehicle 21 than in the past.

[0029] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the present invention, and other techniques may be appropriately combined to the extent possible. Furthermore, publicly known or well-known techniques may be combined to the extent possible.

[0030] For example, in the above embodiment, the mobile terminal 35 downloads the threshold processing unit 33b from the server 33 via the user PC 31 and sets the time threshold T A1 , T A2 However, the present invention is not limited to this configuration. For example, the mobile terminal 35, like the user PC 31, may send the time threshold T A1 , T A2 may be set.

[0031] In the above embodiment, a forklift is used as an example of the vehicle 21, but the vehicle 21 may be a cargo vehicle such as a truck, heavy machinery, or a passenger car, as long as it has a structure that allows it to carry cargo and travel. [Explanation of symbols]

[0032] 1: Sudden acceleration / deceleration determination device 3: 1st judgment part 5: Image recognition unit (second determination unit) 7: Threshold setting section 9: Alarm section 15: Acceleration sensor 21: Vehicle T A :Time threshold T A1 :Time threshold T A2 :Time threshold a1: acceleration threshold

Claims

1. A sudden acceleration / deceleration determination device mounted on a vehicle, the sudden acceleration / deceleration determination device comprising: a first determination unit that determines that the vehicle has suddenly accelerated or decelerated when a state in which acceleration detected by an acceleration sensor that detects acceleration of the vehicle exceeds a predetermined acceleration threshold continues for a time period equal to or greater than a predetermined time threshold, a second determination unit that determines whether the vehicle is loaded with cargo; a threshold setting unit that sets the time threshold to a longer value when the second determination unit determines that a cargo is loaded than when the second determination unit determines that a cargo is not loaded; Equipped with A sudden acceleration / deceleration determination device.

2. When the second determination unit determines that a cargo is loaded, the threshold setting unit increases the time threshold as the amount of cargo loaded increases.

2. The sudden acceleration / deceleration determination device according to claim 1.

3. The second determination unit determines whether the vehicle is carrying a load from an image of a loading section on which the load is carried.

3. The sudden acceleration / deceleration determination device according to claim 1 or 2.

4. A method for determining sudden acceleration / deceleration, comprising: a detection step of detecting acceleration of a vehicle with an acceleration sensor; and a first determination step of determining that the vehicle has suddenly accelerated or decelerated when a state in which the acceleration detected by the acceleration sensor exceeds a predetermined acceleration threshold continues for a time period equal to or longer than a predetermined time threshold, a second determination step of determining whether the vehicle is loaded with cargo; a threshold setting step of setting the time threshold to a value longer than that when it is determined in the second determination step that a cargo is loaded, than when it is determined that no cargo is loaded; Contains A method for determining sudden acceleration / deceleration.

Images