JP7456809B2 - Vehicle testing equipment - Google Patents

Description

The present invention relates to a vehicle testing device.

When performing fuel efficiency tests using a chassis dynamo, it is necessary to set the chassis dynamo to an appropriate running resistance suitable for the vehicle. Running resistance is calculated based on data measured by installing a speedometer in the target vehicle and performing a coasting test on an actual road (straight road) in accordance with regulations. Coasting test is one of the running resistance tests in vehicle testing.Coasting refers to the state where the vehicle is running by inertia without acceleration due to power or deceleration due to brakes.
Then, by setting the running resistance along with vehicle specifications such as vehicle weight on the bench, it becomes possible to conduct tests that simulate actual road driving.

However, there is a possibility that the running resistance coefficient may be mistranscribed or falsified. Therefore, systems that do not involve human intervention have been proposed, such as the invention described in Patent Document 1.

Japanese Patent Application Publication No. 2018-025539

As mentioned above, running resistance is a numerical value used in legal tests, and measurement systems are required to have security measures such as integrity, accountability, and authenticity.

Patent Document 1 describes an invention that improves the integrity of data without human intervention when transmitting running resistance in this measurement system.

Running resistance may be subject to transcription errors or falsification. Furthermore, regardless of whether it is due to human error or intentionality, the problem remains that it is possible to mix up the vehicle itself or the tires installed.
Therefore, an object of the present invention is to guarantee the authenticity of measurement data regarding a vehicle testing device.

In order to achieve the above object, the present invention has the following features:
A vehicle speedometer that measures the speed of the vehicle itself as a vehicle testing device ,
During a vehicle test, and/or before or after the vehicle test, unique information of the vehicle received via a network of the vehicle, and/or unique information of one or more of the parts constituting the vehicle is transmitted to the vehicle. It has a control unit that records together with the measurement data measured by the vehicle speedometer,
If the measurement data by the vehicle speedometer and the vehicle speed information flowing on the network of the vehicle match within a permissible range, the control unit configures the vehicle with unique information of the vehicle and/or with the vehicle speed information flowing on the network of the vehicle. determine that the specific information of the component is correct.
This is a vehicle testing device characterized by the following.

According to the present invention, the authenticity of measurement data can be guaranteed for a vehicle testing device.

FIG. 1 is a configuration diagram of an authentication test system in this embodiment. FIG. 2 is a configuration diagram of the main body of the speed measuring device. It is a block diagram of a weather station. It is a flowchart of the recording process of vehicle specific information. 2 is a flowchart (Part 1) of recording processing of vehicle-specific information and vehicle images. 12 is a flowchart (Part 2) of recording processing of vehicle-specific information and vehicle images. 2 is a flowchart (Part 1) of speed check processing and recording processing of vehicle-specific information and vehicle images. 12 is a flowchart (Part 2) of speed check processing and recording processing of vehicle specific information and vehicle images. FIG. 3 is a diagram showing a photographing operation of a vehicle by a weather station. FIG. 2 is a diagram showing the state of a tire. 2 is a flowchart of tire condition detection processing. 3 is a flowchart of a process for checking vehicle speed during data recording. It is a flowchart of the determination process of whether a vehicle speed is within an allowable range. FIG. 3 is a diagram (part 1) showing a distance calculation operation using a stereo camera. FIG. 2 is a diagram (part 2) showing a distance calculation operation by a stereo camera. FIG. 3 is a diagram showing image processing for calculating vehicle passing speed. FIG. 3 is a diagram showing image processing for calculating vehicle passing speed using markers. FIG. 3 is a diagram showing image processing for marker detection. 2 is a flowchart (Part 1) of a speed check process and a recording process of component specific information and a vehicle image. 12 is a flowchart (part 2) of speed check processing and recording processing of component specific information and vehicle images.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the respective figures. FIGS. 1 and 2 are diagrams illustrating a configuration common to the first to sixth embodiments described below.

FIG. 1 is a configuration diagram of the certification testing system S in this embodiment.
The certification test system S includes a speed measuring device 2 connected to an ECU (Electronic Control Unit) 1 of a vehicle 5 (see FIG. 7) via an in-vehicle network, and a weather station wirelessly connected to the speed measuring device 2. 3 and a stereo camera 4. However, in the first embodiment, this stereo camera 4 is not mentioned.

The ECU 1 is one of computers that electronically controls various elements of the vehicle 5 shown in FIG. 7, which will be described later.
The speed measuring device 2 includes a display device 21, a speed measuring device main body 22, an IMU (Inertial Measurement Unit) 23, and a GPS (Global Positioning System) antenna 24. This speed measuring device 2 is a vehicle testing device that conducts vehicle tests such as coasting tests. A communication terminal of the speed measuring device 2 is connected to an in-vehicle communication network (OBD: On-Board Diagnostics, etc.).

The display device 21 displays the measurement status of the speed measuring device 2, and is, for example, a liquid crystal display. The IMU 23 is a device that measures the behavior of the vehicle 5 by detecting the angle (or angular velocity) and acceleration of three axes governing motion. The GPS antenna 24 is an antenna that receives radio waves emitted by GPS satellites.

The speed measuring device 2 measures the position of the vehicle 5 using radio waves emitted by GPS satellites, and further measures the behavior of the vehicle 5 using the IMU 23. That is, the speed measuring device 2 functions as a vehicle speed meter that measures the speed of the vehicle 5.

FIG. 2 is a configuration diagram of the speed measurement device main body 22.
The speed measurement device main body 22 includes a CPU (Central Processing Unit) 221 , a RAM (Random Access Memory) 222 , a flash ROM (Read Only Memory) 223 , and a wireless module 224 .

The CPU 221 is a control unit that executes a program stored in the flash ROM 223 or the like, and calculates positioning information based on radio waves emitted by GPS satellites. During the vehicle test, and/or before and after the vehicle test, the CPU 221 transmits vehicle speed information received via the vehicle network and/or unique information of one or more parts constituting the vehicle. It is recorded as part of the measurement data measured by the meter.
The flash ROM 223 is a rewritable nonvolatile memory and stores various programs, measurement data, and the like.

The RAM 222 is a volatile memory and is used as a working memory by the CPU 221. The wireless module 224 performs wireless communication with the weather station 3, which will be described later.

FIG. 3 is a configuration diagram of the weather station 3.
The weather station 3 collects weather information in the test environment, and includes a CPU 31, a RAM 32, a flash ROM 33, a wireless module 34, an anemometer 35, and a temperature sensor 36, and is further connected to a stereo camera 4.

The CPU 31 is a control unit that executes a program stored in a flash ROM 33 or the like, and analyzes images obtained by the stereo camera 4. The flash ROM 33 is a rewritable nonvolatile memory, and stores various programs, measurement data, and the like.

The RAM 32 is a volatile memory and is used as a working memory by the CPU 31. The wireless module 34 performs wireless communication with the speed measuring device main body 22.
The anemometer 35 is an anemometer that measures wind speed in the test environment. The temperature sensor 36 is a thermometer that measures the temperature in the test environment.

《First embodiment》
In the first embodiment, vehicle-specific information to be measured is recorded together with measurement data.
FIG. 4 is a flowchart of the coasting test data recording process of the first embodiment.
The speed measuring device 2 is mounted on the vehicle 5 and can communicate with the ECU 1 of the vehicle 5 via an on-vehicle network. The driver accelerates the speed of the vehicle 5 to a prescribed starting speed for starting the test, then coasts, and measures the vehicle speed until it falls below the prescribed finishing speed for ending the test.

The CPU 221 of the speed measuring device main body 22 determines whether or not its own speed exceeds the prescribed starting speed for starting the test (S10). The own speed is the speed calculated by the speed measuring device main unit 22 repeatedly measuring latitude and longitude information from radio waves of GPS satellites and based on changes in this latitude and longitude information, or the Doppler effect of the carrier wave output from the GPS satellite. (hereinafter referred to as GPS speed).
If the speed of the CPU 221 does not exceed the specified starting speed (No), the CPU 221 returns to the process of S10. If the speed of the CPU 221 exceeds the specified starting speed (Yes), the CPU 221 proceeds to step S11.

In step S11, the CPU 221 requests the ECU 1 for vehicle specific information and obtains a response. Also, the vehicle speed (wheel speed), which is vehicle speed information, is acquired. The speed measured by the vehicle here is a speed that corresponds to the number of wheel rotations, so it is also called the wheel speed.
In order to recognize (guarantee) that the CPU 221 is connected to the in-vehicle network to be measured, the CPU 221 compares the GPS speed measured by itself with the vehicle speed information (wheel speed) flowing on the in-vehicle network, and determines whether the GPS speed is acceptable. It is determined whether or not they match within the range (S12). Since the CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy, the CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy, so it determines whether the GPS speed measured by itself and the speed of the vehicle 5 obtained from the ECU 1 via the in-vehicle network are within the allowable range. If they match, it can be guaranteed that the vehicle is connected to the in-vehicle network of the measurement target, and that the acquired vehicle-specific information is that of the measurement target.

If the GPS speed is not within the allowable range for the vehicle speed information (No), the CPU 221 ends the process of FIG. 4 . If the GPS speed is within the allowable range with respect to the vehicle speed information (Yes), the CPU 221 proceeds to step S13.

In step S13, the CPU 221 starts data recording.
During data recording, the CPU 221 determines whether or not its own speed has fallen below the prescribed end speed for ending the test, and whether or not the test stop button has been pressed (S14). If the speed of the CPU 221 is not lower than the specified end speed and the test stop button is not pressed (No), the CPU 221 repeats the determination process in step S14 and continues data recording. If the speed of the CPU 221 falls below the specified end speed or if the test stop button is pressed (Yes), the process proceeds to step S15.

The CPU 221 acquires the vehicle-specific information again (S15), and records the vehicle-specific information acquired at the start of the test and at the end of the test together with the measurement data (S16). Thereafter, the CPU 221 stops data recording (S17) and ends the process of FIG. 4.

By recording the vehicle-specific information together with the measurement data, it is possible to clarify the vehicle on which the test was conducted, and therefore the authenticity of the measurement data can be guaranteed. Note that the vehicle-specific information and measurement data are encrypted to prevent subsequent tampering.

《Second embodiment》
In the second embodiment, vehicle specific information and vehicle images are recorded together with measurement data. The second embodiment will be described below with reference to FIGS. 5A and 5B.
FIGS. 5A and 5B are flowcharts of data recording processing for a coasting test according to the second embodiment.

The CPU 221 of the speed measuring device main body 22 determines whether or not its own speed exceeds the prescribed starting speed for starting the test (S20). If the speed of the CPU 221 does not exceed the specified starting speed (No), the CPU 221 returns to the process of S20. If the CPU 221's own speed exceeds the specified starting speed (Yes), the process proceeds to step S21.

In step S21, the CPU 221 requests the ECU 1 for vehicle-specific information and obtains the response. Also, the vehicle speed (wheel speed), which is vehicle speed information, is acquired.
In order to recognize (guarantee) that the CPU 221 is connected to the in-vehicle network to be measured, the CPU 221 compares the GPS speed measured by itself with the vehicle speed information (wheel speed) flowing on the in-vehicle network, and determines whether the GPS speed is acceptable. It is determined whether or not they match within the range (S22). Since the CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy, the CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy, so it determines whether the GPS speed measured by itself and the speed of the vehicle 5 obtained from the ECU 1 via the in-vehicle network are within the allowable range. If they match, it can be guaranteed that the vehicle is connected to the in-vehicle network of the measurement target, and that the acquired vehicle-specific information is that of the measurement target.

In step S22, if the GPS speed is not within the allowable range for the vehicle speed information (No), the CPU 221 ends the process of FIG. 5A. If the GPS speed is within the allowable range with respect to the vehicle speed information (Yes), the CPU 221 proceeds to step S23.

In step S23, the CPU 221 starts data recording. The following steps S24 to S29 are processes during data recording.

In parallel with this, when the power of the weather station 3 is turned on, the CPU 31 of the weather station 3 determines whether a wireless connection has been established to the speed measuring device 2 mounted on the vehicle (S40). If the CPU 31 cannot establish a wireless connection to the speed measuring device 2 (No), the process returns to step S40, and if it can establish a wireless connection to the speed measuring device 2 (Yes), the CPU 31 proceeds to the determination process of step S41.

In step S41, the CPU 31 determines whether the vehicle 5 has been photographed within the image frame. If the vehicle 5 is not photographed within the image frame (No), the CPU 31 returns to the process of step S40, and if the vehicle 5 is photographed within the image frame (Yes), after transmitting the vehicle image ( S42), the process returns to step S40. The reception process corresponding to the transmission process in step S42 is described in step S24, which will be described later.

During data recording, the CPU 221 receives vehicle images from the weather station 3 (S24) and records the vehicle images as part of the measurement data (S25). Furthermore, the CPU 221 determines whether its own speed has fallen below the specified end speed for the end of the test and whether the test stop button has been pressed (S26). If the CPU 221's own speed has not fallen below the specified end speed and the test stop button has not been pressed (No), the CPU 221 continues data recording and returns to the processing of step S26. If the CPU 221's own speed has fallen below the specified end speed or the test stop button has been pressed (Yes), the CPU 221 proceeds to step S27.

The CPU 221 acquires the vehicle-specific information again (S27), and records the vehicle-specific information acquired at the start of the test and at the end of the test together with the measurement data (S28). Thereafter, the CPU 221 stops data recording (S29) and ends the process of FIG. 5B.

By recording vehicle-specific information and vehicle images together with measurement data, it is possible to clarify the vehicle on which the test was conducted, and therefore the authenticity of the measurement data can be guaranteed. In addition, by saving the exterior of the vehicle 5 as an image, it is possible to confirm after the fact whether the conditions related to air resistance, such as not folding the side mirrors, were appropriate. Note that the vehicle-specific information, vehicle image, and measurement data are encrypted to prevent subsequent tampering.

《Third embodiment》
In the third embodiment, vehicle specific information, vehicle images, passing speed, and tire information are recorded together with measurement data.
FIGS. 6A and 6B are flowcharts of data recording processing for a coasting test according to the third embodiment.

The CPU 221 of the speed measuring device main body 22 determines whether or not its own speed exceeds the specified starting speed (S50). If the speed of the CPU 221 does not exceed the specified starting speed (No), the CPU 221 returns to the process of S50. If the CPU 221's speed exceeds the specified starting speed (Yes), the CPU 221 proceeds to step S51.

In step S51, the CPU 221 requests the ECU 1 for vehicle-specific information and obtains the response. Also, the vehicle speed (wheel speed), which is vehicle speed information, is acquired.
In order to recognize (guarantee) that the CPU 221 is connected to the in-vehicle network to be measured, the CPU 221 compares the GPS speed measured by itself with the vehicle speed information (wheel speed) flowing on the in-vehicle network, and determines whether the GPS speed is acceptable. It is determined whether or not they match within the range (S52). The CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy. Therefore, the CPU 221 determines that the GPS speed measured by itself and the speed of the vehicle 5 obtained from the ECU 1 via the in-vehicle network match within a permissible range, and that the CPU 221 is connected to the in-vehicle network to be measured. Furthermore, it can be guaranteed that the acquired vehicle-specific information is the one to be measured.

In step S52, if the GPS speed is not within the allowable range for the vehicle speed information (No), the CPU 221 ends the process of FIG. 6A. If the GPS speed is within the allowable range with respect to the vehicle speed information (Yes), the CPU 221 proceeds to step S53.

In step S53, the CPU 221 starts data recording. The following steps S54 to S61 are processes during data recording.

In parallel with this, when the power of the weather station 3 is turned on, the CPU 31 of the weather station 3 determines whether a wireless connection has been established to the speed measuring device 2 mounted on the vehicle (S70). If the CPU 31 cannot establish a wireless connection to the speed measuring device 2 (No), the process returns to step S70, and if it can establish a wireless connection to the speed measuring device 2 (Yes), the CPU 31 proceeds to the determination process of step S71.

In step S71, the CPU 31 determines whether the vehicle 5 has been photographed within the image frame. If the vehicle 5 is not photographed within the image frame (No), the CPU 31 returns to the process of step S70, and if the vehicle 5 is photographed within the image frame (Yes), the After performing the image processing shown in 9 and calculating the passing speed (S72), tire information is calculated (S73). Details of the tire information calculation process will be explained later with reference to FIGS. 7 and 8. Details of the passing speed calculation process will be explained with reference to FIGS. 12A and 12B and FIGS. 13 to 15, which will be described later.

After transmitting the tire information and the like (S74), the CPU 31 returns to the process of step S70. The reception process corresponding to the transmission process in step S73 is described in step S54, which will be described later.

During data recording, the CPU 221 receives the vehicle image, passing speed, and tire information from the weather station 3 (S54). In order to ensure that the image is a vehicle image to be measured, the CPU 221 compares the acquired passing speed with the GPS speed measured by itself, and determines whether they match within an allowable range ( S55). Since the CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy, it is assumed that the GPS speed measured by itself and the passing speed calculated from the image match within the allowable range. , it is possible to guarantee that the image is of the vehicle to be measured.

In step S55, if the GPS speed does not match the passing speed within an acceptable range (No), the CPU 221 terminates the processing of FIG. 6B; if the GPS speed matches the passing speed within an acceptable range (Yes), the CPU 221 sets a speed OK flag (S56) and then proceeds to processing of step S57.
In step S57, the CPU 221 records the vehicle image, the passing speed, the tire information, and the speed OK flag as part of the measurement data.

Furthermore, the CPU 221 determines whether or not its own speed has fallen below the specified end speed for ending the test, and whether or not the test stop button has been pressed (S58). If the CPU 221's speed is not lower than the specified end speed and the test stop button is not pressed (No), the CPU 221 returns to step S58 while continuing data recording. If the speed of the CPU 221 falls below the specified end speed or if the test stop button is pressed (Yes), the process proceeds to step S59.

The CPU 221 acquires the vehicle-specific information again (S59), and records the vehicle-specific information acquired at the start of the test and at the end of the test together with the measurement data (S60). Thereafter, the CPU 221 stops data recording (S61) and ends the process of FIG. 6B.

In addition to vehicle-specific information, recording the vehicle image, passing speed, tire information, and speed OK flag as part of the measurement data makes it possible to clearly record the test implementation status, thereby ensuring the authenticity of the measurement data. can be guaranteed. In order to prevent subsequent tampering, the vehicle unique information, vehicle image, passing speed, tire information, and speed OK flag are encrypted.

《Fourth embodiment》
In the fourth embodiment, a camera is used to photograph a vehicle under test, and the vehicle speed is calculated from a series of photographed image frames. It is difficult to forge and match the photographed image of the test vehicle, the vehicle speed calculated from a series of photographed image frames, and the vehicle speed data measured by the vehicle speedometer without contradiction. Therefore, by recording the vehicle speed measured by the vehicle speedometer, the photographed image of the test vehicle, and the vehicle speed calculated from a series of photographed image frames, it is possible to determine the authenticity of the measurement data.

FIG. 7 is a diagram showing the operation of photographing a vehicle by the weather station 3.
The weather station 3 is equipped with a stereo camera 4 for observing passing vehicles. This stereo camera 4 is installed near the center of the test section so that the optical axis of the stereo camera 4 is approximately 90 degrees with respect to the test road. The CPU 31 of the weather station 3 uses a series of multiple images obtained from the stereo camera 4 to sequentially calculate the passing speed of the vehicle 5 included in the image frame.

This vehicle 5 is equipped with tires 51 to 54.
FIG. 8 is a diagram showing an example of the state of the tire 51 photographed by the stereo camera 4. As shown in FIG.
The side surface of the tire 51 is approximately circular and includes a central wheel rim 512 and an outer peripheral portion 511 made of rubber. The diameter of the wheel rim 512 is r. The width of the outer peripheral portion 511 in the radial direction is T. Since the outer peripheral portion 511 is an elastic body, it sinks by a sinking amount s.

When the stereo camera 4 photographs the tires 51 and 52 and the distance scale described later can be calculated, the actual diameter of the tire wheel can be calculated. By comparing the actual diameter of the tire wheel with the standard tire wheel size input in advance, it is possible to determine whether the wheel size of the test vehicle is suitable.

In addition, by image measurement of tires, it is possible to obtain the brand, aspect ratio, and amount of sinkage (depending on speed, vehicle weight, and air pressure), and then collate, judge, and record them. Thereby, it is also possible to determine whether the condition of the tire is suitable for the coasting test.

FIG. 9 is a flowchart of image processing for calculating vehicle passing speed and tire information. This process shows details of the process of steps S71 and S72 shown in FIG. 6A.
In step S80, the CPU 31 acquires an image frame at time t from the stereo camera 4 and stores it in a memory such as the RAM 32.

The CPU 31 determines whether a moving object is present in the frame based on the background difference (S81). If the moving object is not within the frame (No), the CPU 31 retains this frame as a background image (S83) and returns to the process of step S80; if the moving object is within the frame, the CPU 31 proceeds to the process of step S82. .

In step S82, the CPU 31 calculates the difference between the image frames at times t and t-1 and the background image, and extracts a moving object area. Then, the CPU 31 determines whether the moving object area crosses the center (S84). If the CPU 31 determines that the moving object area does not cross the center (No), the process returns to step S80, and if it determines that the moving object area crosses the center (Yes), calculates the amount of displacement of the moving object area. (S85).

The timing at which the moving object area crosses the center is the timing at which the center point of the vehicle 5 comes closest to the center of the image frame, and also the timing at which the vehicle 5 passes in front of the camera. When the vehicle 5 passes in front of the stereo camera 4, the most appropriate external image of the vehicle 5 can be obtained by the stereo camera 4, and the wireless communication between the speed measuring device 2 and the weather station 3 is the best. Can be performed well.

In step S86, the CPU 31 calculates the distance from the stereo camera 4 to the moving object (vehicle) based on the image frame captured by the stereo camera 4. This allows the CPU 31 to convert the image-measured tire wheel diameter [Pixel] into an actual diameter [m]. Further, the CPU 31 calculates the displacement amount [Pixel] of the moving object on the image frame and the actual moving distance [m], and further calculates the passing speed from the frame rate of the camera (S87).

Then, the CPU 31 recognizes the front and rear tires from within the image frame, calculates the actual lengths in the vertical and horizontal directions (S88), and ends the process of FIG.
Thereby, the CPU 31 can confirm that at least the wheel size is compatible by comparing with the standard tire and wheel size input in advance. Furthermore, the CPU 31 can image measure the tire, acquire its brand, aspect ratio, and amount of depression (depending on speed, vehicle weight, and air pressure), and collate, judge, and record the information.

The speedometer measures the vehicle's speed with high accuracy. The speed obtained from the camera is consistent with the speed measured by the speedometer. It is difficult to forge this data and make it consistent without any contradictions. Therefore, by comparing the speed measured by the speedometer with the speed obtained from the camera, it is possible to determine the authenticity of the measurement data.

Fifth embodiment
The fifth embodiment involves recording data through testing and processing the recorded data afterwards.
FIG. 10 is a flow chart of a process for checking the vehicle speed during data recording.
The processing in steps S100 to S103 is a series of processing for recording data from a test.

The CPU 221 of the speed measuring device main body 22 determines whether or not its own speed exceeds the prescribed starting speed for starting the test (S100). If the own speed is less than the specified starting speed (No), the process of step S100 is repeated, and if the own speed exceeds the specified starting speed (Yes), the process proceeds to step S101.

In step S101, the CPU 221 starts recording data obtained from the measuring instrument, vehicle-specific information and vehicle speed information obtained from the vehicle side. Here, the vehicle speed obtained from the vehicle side does not need to be written to a file, but may be managed in memory and, after comparison with measuring instrument data, discarded if there is no problem. Vehicle-specific information obtained from the vehicle side does not change over time. For this reason, the CPU 221 may store only the first one, and thereafter check whether it has changed at the acquired timing.

The CPU 221 determines whether or not its own speed has fallen below the prescribed end speed for ending the test, and whether or not the test stop button has been pressed (S102). If the CPU 221 determines that its own speed has not fallen below the specified end speed and the test stop button has not been pressed (No), the CPU 221 returns to the process of step S102 and determines whether its own speed has fallen below the specified end speed. Alternatively, if the test stop button is pressed (Yes), data recording is stopped (S103), and the process proceeds to step S104.

In step S104, the CPU 221 performs vehicle speed comparison processing. This vehicle speed comparison process will be explained in detail with reference to FIG. 11, which will be described later.
In step S105, the CPU 221 determines whether the speed obtained from the vehicle 5 is within an allowable range with respect to the GPS speed. If the speed obtained from the vehicle 5 is within the allowable range of GPS speed (Yes), the CPU 221 proceeds to step S106, and if the speed obtained from the vehicle 5 is outside the allowable range of the GPS speed, the CPU 221 ends the process of FIG. .
In step S106, the CPU 221 records the speed OK flag and ends the process of FIG.

FIG. 11 is a flowchart of a process for determining whether the vehicle speed is within the allowable range. This determination process is called from step S104 in FIG.
In step S110, the CPU 221 sets a variable N indicating the data number to 0, and starts a series of determination processes.

In step S111, the CPU 221 obtains the GPS vehicle speed V at data number N and the vehicle speed U obtained from the vehicle side. Then, the CPU 221 determines whether the vehicle speed V and the vehicle speed U satisfy the following equation (1) (S112).

This equation (1) determines that the vehicle speed U is 90 to 110% of the vehicle speed V. In other words, the allowable range of vehicle speed U is 90 to 110% of vehicle speed V. The display error of speedometers installed in vehicles is regulated by law and checked during vehicle inspections. Therefore, most of the vehicles that pass the vehicle inspection satisfy the above formula (1).

If the vehicle speed V and the vehicle speed U satisfy the formula (1) (Yes), the CPU 221 adds 1 to the variable N indicating the data number (S113), and proceeds to step S114, where the vehicle speed V and the vehicle speed U satisfy the formula ( If 1) is not satisfied (No), it is determined that the vehicle speed U is outside the allowable range (S116), and the process of FIG. 11 is ended.

In step S114, the CPU 221 determines whether the variable N exceeds the number of recorded data. If the variable N is less than or equal to the number of recorded data (No), the CPU 221 returns to the process of step S111, and if the variable N exceeds the number of recorded data (Yes), the CPU 221 determines that the vehicle speed U is within the allowable range (S115). ), the process in FIG. 11 ends.

In addition to the vehicle-specific information, by recording the GPS vehicle speed V and the vehicle speed U obtained from the vehicle side as part of the measurement data, it is possible to clearly record the test implementation status. The authenticity of the measured data can be guaranteed by matching the vehicle speed V and the vehicle speed U within the allowable range over the entire recording range. Note that the vehicle unique information, vehicle speed, and speed OK flag are encrypted to prevent subsequent tampering.

Here, a method for measuring vehicle speed (passing speed) using images will be explained.
FIGS. 12A and 12B are diagrams showing the distance calculation operation by the stereo camera 4. FIG. 12A is a diagram of the stereo camera 4 viewed from above. FIG. 12B is a diagram of the stereo camera 4 viewed from the right side.

The stereo camera 4 includes cameras 4L and 4R. The optical axes of the cameras 4L and 4R are parallel and included in the same horizontal plane, and are separated by a distance b. The origin O is the midpoint between the cameras 4L and 4R. The horizontal angle of view of each camera 4L, 4R is θ.

The subject P is separated from the origin O by a distance Z in the optical axis direction, by a distance X to the right, and by a distance Y above.
When viewed from the camera 4L, the subject P appears at a distance x _l to the right and a distance y _l above in the image coordinate system of focal length f. When viewed from the camera 4R, the subject P appears at a position a distance x _r to the left and a distance y _r (=y _l ) above in the image coordinate system of focal length f. This has the relationship expressed by the following equations (2) and (3).

The ratio between the focal length f and the distance Z is expressed by the following equation (4). Note that the difference in the number of pixels between the distance x _l and the distance x _r is called parallax.

If this is rearranged with respect to the coordinates of the subject P, the following equations (5), (6), and (7) can be obtained.

The number of horizontal pixels with the origin O of the camera coordinates as the optical axis is expressed as 2x _max . Here, Δx is the actual size from the center of the angle of view of the stereo camera 4 to the left end of the angle of view of the stereo camera 4 at the distance Z. The angle θ is the angle of view of the camera 4L.

From this, the actual size on the object plane corresponding to 1 pixel can be obtained as the scale factor _δX in the X direction as shown in equation (9).

Note that if the aspect ratio of the pixels of the stereo camera 4 is 1, the scale coefficient δ _X in the X direction and the scale coefficient δ _Y in the Y direction are equal. Hereinafter, the scale factor will be simply written as δ.
From the above, the vehicle speed U [mm/s] can be calculated as shown in equation (10). Here, ΔL[pixel] is the amount of pixel displacement between frames regarding the moving object (vehicle 5). F is the camera frame rate [frames/s]. δ [mm/pixel] is a scale factor that converts pixels on the image frame to the actual size on the object plane.

Note that instead of calculating δ using a stereo camera, the distance Z, Δx, etc. using a monocular camera may be input in advance.

FIG. 13 is a diagram showing image processing for calculating vehicle passing speed.
Image frame 63 is a frame at time t, in which a vehicle is photographed.
Image frame 61 is immediately before image frame 63 and is a frame at time t-1, so the vehicle being photographed is located slightly to the left. Image frame 62 is a background frame in which no vehicle is photographed.

The image frame 64 is a difference image obtained by subtracting the brightness value of the background image frame 62 from the brightness value of the image frame 61. This cancels out the background to black and clearly shows the vehicle.
The image frame 65 is a difference image obtained by subtracting the brightness value of the background image frame 62 from the brightness value of the image frame 63. This cancels out the background to black and clearly shows the vehicle.

The image frame 66 is obtained by binarizing the image frame 64 and removing noise. At this time, the right end of the vehicle is at a pixel position L(t-1) from the left end of the image frame 66.
Image frame 67 is obtained by binarizing image frame 65 and removing noise. At this time, the right end of the vehicle is at a pixel position L(t) from the left end of the image frame 67.

At this time, the inter-frame pixel displacement amount ΔL is obtained by subtracting L(t-1) from L(t).

FIG. 14 is a diagram showing image processing for calculating vehicle passing speed using markers.
Image frame 72 is a frame at time t, in which a vehicle with a marker attached is photographed.
Image frame 71 is immediately before image frame 72 and is the frame at time t-1, so the vehicle being photographed has a marker attached and is located slightly to the left of the frame at time t. ing.
The marker 73 is the same image as the marker attached to the center of the side of the vehicle. The CPU 31 of the weather station 3 can specify the position of the vehicle 5 by tracking the image frames 71 and 72 using the marker 73.

Image frame 74 is obtained by tracking marker 73 on image frame 71. The position of this marker is the pixel position L(t-1) from the left end.
Image frame 75 is obtained by tracking marker 73 on image frame 72. The position of this marker is the pixel position L(t) from the left end.

At this time, the inter-frame pixel displacement amount ΔL is obtained by subtracting L(t-1) from L(t).

FIG. 15 is a diagram showing image processing for marker detection.
The marker image 81 is known, and the image frame 82 includes a predetermined pattern (marker).

The CPU 31 performs vertical and horizontal tracking scanning on the image frame 82 using a rectangle of a predetermined size, and compares it with the marker image 81 . At this time, the CPU 31 determines that a predetermined pattern has been found on the image frame 82 if the difference (degree of difference) between the marker image 81 and the rectangle is 0 or close to it. In this way, the CPU 31 can detect a predetermined marker from the image frame.

《Sixth embodiment》
The sixth embodiment uses part-specific information as alternative information to vehicle-specific information. Part-specific information includes not only serial numbers but also information such as product model numbers, lot numbers, and manufacturing dates. For example, if lot numbers of 100 parts are collected, it is expected that approximately one vehicle equipped with a combination of them can be identified. Therefore, the part-specific information can be used as alternative information to the vehicle-specific information. Possible parts-specific information includes, for example, a tire sensor serial number, a catalyst sensor serial number, and the like.
The speed measuring device 2 may further include in the measurement data state values of components that greatly affect the test. This makes it possible to demonstrate the validity of the measurement data.

16A and 16B are flowcharts of the speed check process and the recording process of part-specific information and vehicle images according to the sixth embodiment.
The CPU 221 of the speed measuring device main body 22 judges whether or not its own speed exceeds the prescribed start speed for the start of the test (S120). If its own speed does not exceed the prescribed start speed (No), the CPU 221 returns to the process of S120. If its own speed exceeds the prescribed start speed (Yes), the CPU 221 proceeds to the process of step S121.

In step S121, the CPU 221 requests the part-specific information from the ECU 1 and acquires a response thereto. The CPU 221 also acquires the vehicle speed (wheel speed) which is the vehicle speed information.
In order to recognize (guarantee) that the CPU 221 is connected to the in-vehicle network to be measured, the CPU 221 compares the GPS speed measured by itself with the vehicle speed information (wheel speed) flowing on the in-vehicle network and determines whether or not they match within an allowable range (S122). The CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy. Therefore, the CPU 221 can guarantee that the CPU 221 is connected to the in-vehicle network to be measured and that the acquired part-specific information is that of the measurement target by checking that the GPS speed measured by the CPU 221 matches the speed of the vehicle 5 obtained from the ECU 1 via the in-vehicle network within an allowable range.

In step S122, if the GPS speed is not within the allowable range for the vehicle speed information (No), the CPU 221 ends the process of FIG. 16B. If the GPS speed is within the allowable range with respect to the vehicle speed information (Yes), the CPU 221 proceeds to step S123.

In step S123, the CPU 221 starts data recording. The following steps S124 to S128 are processes performed during data recording.

In parallel with this, when the power of the weather station 3 is turned on, the CPU 31 of the weather station 3 determines whether a wireless connection has been established to the speed measuring device 2 mounted on the vehicle (S140). If the CPU 31 cannot establish a wireless connection to the speed measuring device 2 (No), the process returns to step S140, and if it can establish a wireless connection to the speed measuring device 2 (Yes), the CPU 31 proceeds to the determination process of step S141.

In step S141, the CPU 31 determines whether the vehicle 5 has been photographed within the image frame. If the vehicle 5 is not photographed within the image frame (No), the CPU 31 returns to the process of step S140, and if the vehicle 5 is photographed within the image frame (Yes), the CPU 31 displays the image for this image frame. 9 is performed (S142), and the passing speed and tire information are calculated. Details of the tire information calculation process have been explained with reference to FIGS. 7 and 8. Details of the passing speed calculation process have been described with reference to FIGS. 12A, 12B, and 13 to 15.

After transmitting the vehicle image, passing speed, and tire information (S143), the CPU 31 returns to the process of step S140. The reception process corresponding to the transmission process in step S143 is described in step S124, which will be described later.

During data recording, the CPU 221 receives the vehicle image, passing speed, and tire information from the weather station 3 (S124). In order to ensure that the vehicle is the measurement target, the CPU 221 compares the acquired passing speed with the GPS speed measured by itself, and determines whether they match within an allowable range (S125 ). Since the CPU 221 of the speed measuring device main body 22 measures the speed of the vehicle 5 with high accuracy, it is assumed that the GPS speed measured by itself and the passing speed calculated from the image match within the allowable range. , it is possible to guarantee that the image is of the vehicle to be measured.

In step S125, if the GPS speed does not match the passing speed within the allowable range (No), the CPU 221 ends the process of FIG. 16B, and the GPS speed is allowed relative to the passing speed. If they match within the range (Yes), a speed OK flag is set (S126) and the process advances to step S127.
In step S127, the CPU 221 records the vehicle image, passing speed, tire information, and speed OK flag as part of the measurement data.

The CPU 221 further determines whether its own speed has fallen below the specified end speed for the end of the test and whether the test stop button has been pressed (S128). If the CPU 221's own speed has not fallen below the specified end speed and the test stop button has not been pressed (No), the CPU 221 continues recording data and returns to the process of step S128. If the CPU 221's own speed has fallen below the specified end speed or the test stop button has been pressed (Yes), the CPU 221 proceeds to step S129.

The CPU 221 acquires the component-specific information again (S129), and records the component-specific information acquired at the start of the test and at the end of the test together with the measurement data (S130). Thereafter, the CPU 221 stops data recording (S131) and ends the process of FIG. 16B.

By recording the part-specific information together with the measurement data, it is possible to clarify the vehicle on which the test was conducted, and therefore the authenticity of the measurement data can be guaranteed. Note that the component-specific information and measurement data are encrypted to prevent subsequent tampering.

(Modification)
The present invention is not limited to the above-described embodiment, and modifications can be made without departing from the spirit of the present invention. For example, the following modifications are possible:

(a) When the measurement data is edited and processed by a worker, it may be recorded as a history together with worker-specific information.
(b) The measurement data may include, in addition to the vehicle-specific information, the measurement device's specific information and the driver's specific information.
(c) In addition to using component-specific information as alternative information for vehicle-specific information, both vehicle information and component-specific information may be included in the measurement data.
(d) The present invention is not limited to coasting tests, but may be applied to external noise measurements, fuel efficiency tests, braking tests, etc.
(e) The timing at which the speed measuring device records the unique information of the vehicle and/or the unique information of one or more of the parts that make up this vehicle is not limited to before or after the vehicle test, but may be during the vehicle test. Good too.

1 ECU
2 Speed measuring device (vehicle testing device)
21 Display device 22 Speed measuring device main body 221 CPU
222 RAM
223 Flash ROM
224 Wireless module 23 IMU
24 GPS antenna 3 Weather station 31 CPU
32 RAM
33 Flash ROM
34 Wireless module 35 Anemometer 36 Air temperature sensor 4 Stereo camera 4L Camera 4R Camera 5 Vehicles 51 to 54 Tires 511 Outer periphery 512 Wheel rims 61 to 67, 71, 72, 74, 75, 82 Image frame 81 Marker image 73 Marker

Claims (3)

A vehicle speedometer that measures the speed of the vehicle itself as a vehicle testing device ,
During a vehicle test, and/or before or after the vehicle test, unique information of the vehicle received via a network of the vehicle, and/or unique information of one or more of the parts constituting the vehicle is transmitted to the vehicle. It has a control unit that records together with the measurement data measured by the vehicle speedometer,
If the measurement data by the vehicle speedometer and the vehicle speed information flowing on the network of the vehicle match within a permissible range, the control unit configures the vehicle with unique information of the vehicle and/or with the vehicle speed information flowing on the network of the vehicle. determine that the specific information of the component is correct.
A vehicle testing device characterized by: A vehicle speedometer that measures the speed of the vehicle itself as a vehicle testing device ,
During a vehicle test, and/or before or after the vehicle test, unique information of the vehicle received via a network of the vehicle, and/or unique information of one or more of the parts constituting the vehicle is transmitted to the vehicle. It has a control unit that records together with the measurement data measured by the vehicle speedometer,
The control unit estimates a vehicle speed from an image of the vehicle taken by a camera, and if the measured data by the vehicle speedometer and the vehicle speed information estimated from the photographed image match within a permissible range, determining that unique information of the vehicle and/or unique information of parts constituting the vehicle is correct;
A vehicle testing device characterized by: The control unit records the image of the vehicle captured by the camera together with the measurement data measured by the speedometer.
3. The vehicle testing apparatus according to claim 2.

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