JPS60189091A - Operation recorder for vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a digital driving recorder mounted on a vehicle such as a truck.

[Background of the invention]

Conventionally, a driving recorder that records vehicle speed, engine speed, etc., is configured to record the vehicle speed, distance traveled, and engine speed in an analog manner using a printing needle on a recording paper that rotates over time. In this case, vehicle speed and engine speed are measured mechanically by using centrifugal force to move the printing needle. However, in recent years, vehicle speed and engine rotation speed have been measured electronically.
A method of digitally displaying information on the driver's seat display is becoming popular. When a vehicle equipped with such a digital display section is equipped with a driving recorder, it is necessary to take the trouble of installing a mechanical vehicle speed measurement mechanism or engine rotation speed measurement mechanism as described above, which is uneconomical. It had become. In addition, mechanical measurement and recording methods require manual calculation each time to obtain the average vehicle speed and cumulative travel distance, making operation management extremely troublesome.

As a means to solve this problem, electronically detected data regarding engine speed, vehicle speed, etc. is stored digitally over time, and as necessary, this stored data can be printed directly or after statistical processing and digitally printed. (Japanese Patent Application No. 56-117728). However, this digital driving recorder also has the following drawbacks.

The Road Traffic Act's regulations regarding driving recorders clearly state that instantaneous speeds must be recorded. In order to satisfy this condition in a digital driving recorder, it is necessary to reduce the sampling period for speed recording to 1 second or less, and to record the driving of -day, the storage capacity becomes enormous. This recording can be done using a storage medium such as a cassette tape, but the in-storage capacity is impractical if it is handled by a random access memory (hereinafter referred to as RAM). When retrieving driving records from a storage medium, cassette tapes have problems such as a long playback time, and there is a strong demand for the use of AM packs in which a large number of RAMs are arranged on a cassette board. However, this large storage capacity is due to 11.
This is a major drawback for a driving recorder using an AM bank. Therefore, as a solution to this problem, by taking advantage of the fact that the speed of the vehicle does not change suddenly, and by interpolating data when reproducing speed data even if the speed sampling period is lengthened, it is possible to reproduce the instantaneous speed. compress the data into
There is a method which aims to substantially reduce the storage data enlightenment (Japanese Patent Application No. 138,600/1982). This data compression is performed as follows.

The error range of a vehicle speedometer stipulated by the Road Traffic Act is approximately ±3 km/h at a speed of 35 km/h. Therefore, even in the digital sampling state, the vehicle speed between samplings or the value at the time of sampling must be ±3 k
If the sampling period is set to fall within m/h, it is considered that the instantaneous speed is measured within the error range of the vehicle speedometer even in a digital system. FIG. 1 is a diagram for explaining the numerical value of this sampling period. Here, considering that the acceleration/deceleration of the vehicle is absolutely below ±IQ (G=9.8 m/s2), the maximum acceleration of the vehicle is considered to be ±IG.

Figure 1 shows the vehicle speed v(, sampled at time to, the vehicle is suddenly accelerated or decelerated between time to and time 11, and the vehicle speed vI sampled at time tl).
Assuming that the value is Hv2 + v3 + v4, etc., at time t. This figure shows the vehicle speed error δ between the actual vehicle speed between and tl and the value obtained by linear interpolation between the sampling speeds. The error δ is, like point A, between time to and 1. The maximum value is reached when the maximum acceleration/deceleration change occurs midway between As mentioned above, change this error δ to ±3 km/h.
When calculating the conditions below, the sampling interval is 0.
It will take less than 2 seconds.

In this way, if the sampling interval is set to 0.2 seconds, the instantaneous velocity can be recorded even with a digital system.

In reality, the maximum acceleration/deceleration of the vehicle is about 0.8 G, so a sampling interval of about 0.25 seconds is sufficient. Here, the maximum vehicle speed is 120 km/h, and the vehicle speed resolution is 2.
If km/h, the amount of information is 6 bits. To record this for 24 hours at a cycle of 0.2 seconds, 2.
At 6 megabits, it is so large that it is almost impossible to store the amount of information in DRAM. Therefore, the data is compressed by an interpolation method as shown in FIG.

In this data compression, the speed is sampled at a sampling interval of 0.2 seconds, and compared to 0.2 seconds, the speed is sampled for a sufficiently long time (tl-to), about 10 seconds by the microprocessing unit (hereinafter referred to as MPU). ) is stored in the internal RAM. After this process, time to and 1. The sampling rates vO and vl at and are interpolated by a straight line. Then, this interpolated value is compared with the above sampled values at 0.2 second intervals, and all of these comparison values are 3 ktn.
/ h or less, record to the RAM pack at time t
The speed of o and tl is v (1 and Vl). On the other hand, if even one of all comparison values exceeds 3 km/h, it is 0
．． All speeds sampled at 2-second intervals are recorded. However, with this method, 0.
One bit of information is required to distinguish between 2 second and 10 second interval recordings. If this method is adopted, 2
If you were able to record all 4 hours at 10 second intervals, 60
Becomes a gyro pit.

However, in reality, some recording portions at 0.2 second intervals are included, so the memory size is about 150 kilobits, which can be much smaller than the 2.6 megabits mentioned above.

3 to 5 show the basic configuration of a conventional digital driving recorder that performs data compression. Third
In the figure, the vehicle speed of the vehicle 10 is determined by the vehicle speed sensor 2,
The engine rotation speed of the engine 14 is determined by the engine rotation sensor 1.
6 is detected and input to the processing device 18.
Work distinctions such as driving, work, and rest, and cargo information necessary for operation records are input from the data input device 20 to the processing device 18. These pieces of information are displayed on the display device 22, and
It is stored in an external storage device 24 that is detachably provided in the processing device 18.

- When the operation for the day ends, the external storage device 24 is removed from the processing device 18 and connected to the data analysis device on the ground side, so that it can be used to create the final operation record.

As shown in FIG. 4, the engine rotation speed sensor 6 is composed of a coater magnet 26 and a stator coil 2B, and detects the rotation of the rotor magnet 26 in the stator coil 28. The output of the stator coil 28 is inputted to the processing device 18 via an amplifier 1fagM 30 and a comparator 32.

The vehicle speed sensor 12 also includes a rotor magnet 34 and a stator coil 36, and the output from the stator coil 36 is inputted to the processing device 18 via an amplifier 38 and a comparator 40.

In the processing device 18, as shown in FIG.
Data from the vehicle speed sensor 12 and engine rotation sensor 16 is taken in via the 0-intern ace 46 and stored in the internal memory 48 for a certain period of time. In addition, the real time generation circuit (
The time when the data is generated by the RTC) 50 is captured by the MPU 44 and then displayed on the display device 22 via the I10 intern ace 52. For the vehicle number, press the vehicle number switch 5
4 to MPU 44 via I10 interface 52
and recorded in the external storage device 24. The external storage device 24 is a so-called R memory device equipped with a plurality of RAMs.
, AM pack, which are connected to the MPU by a bus 60 via a connector 56 and an I10 interface 58.

As shown in FIG. 6, in step 62, the MPU 44 samples the speed during a fixed time interval T at intervals of Δ, and in step 64, the sampling speed values VQ, Vl...°・V is written into the internal memory 48. Next, in step 66, it is assumed that the sampling speed value V.~■ changes linearly in speed, and this is divided by T/Δ and each value is calculated as Vo +
v, l... vo is calculated. In step 68, when the difference between the sampling value v1 and the corresponding linearly calculated value vI is smaller than a predetermined value ΔV, that is, when 1vI−Vl<ΔV, the velocity wave record is
Only the values of □v, , are recorded in the RAM block in the external storage device 24. Moreover, if the difference between the sampling value vl and the linearly calculated value v1 is greater than or equal to ΔV, that is, if even one of 1vI−v11≧ΔV holds true, then v
o, vl...Vl,...V.

Store all values of , and mark Δ to indicate division. Thereafter, the processing device 18 returns to step 70 and calculates the distance 1filti'f*lH for every traveling distance M1klTI.
, L into the external storage device 24, and other information is entered in step 72.

As another example of this data compression method, the one shown in FIG. 7 is an application of the Oke IHj method. This is done by taking a time interval tn-ty as the processing section and interpolating the speed of the fish during this time with several straight lines such that it falls within the tolerance level of ±ΔV as shown in the figure.7' t, but in this case, the time α1 . of each recording point relative to the time l t o. α2. α3. . . . α. must be recorded together with the velocity information Vl, V2 . This programming process-C takes the constant time interval T of step 62 in FIG. 6 as the sampling point 21, and
V+ 1<ΔV (7)? Perform 14J determination. Furthermore, the condition was not met and Sanf reached 7.1 near)'.

Increase the ring points one by one, repeat the above 0 constant, set the point before the point where this condition is broken as the next reference point, and then repeat the above 0 constant. By returning the number of points, the number of force points shown in Figure 7 can be obtained.

In the latter case, the basic amount of data increases because it is necessary to record both speed and time, but experiments show that the total amount of data is smaller.

FIG. 8 shows the data compression timing of a conventional driving recorder. In this data compression, the velocity data vl + v2 + . . . vl within a certain period of time T is recorded, then subjected to the compression processing described above, and the result after this processing is recorded in the AM node. For this reason, for example, the eighth
If an accident occurs between times t1 and t2 in the figure, and the driving recorder stops operating at that point, such as when the driving record h1 is turned off, the speed data from time t1 to the time of the accident is not recorded. One of the important functions of a driving recorder is to be able to grasp vehicle operating conditions such as vehicle speed when an accident occurs and in accident analysis. 711)
As mentioned above, the possibility that data at the time of an accident may not be recorded is a major problem, and is a drawback of a digital driving recorder that compresses data. The compression V of this data is carried out in the processing device. That is, the processing device 18, as shown in FIG. The rotation signal is transmitted via the I10 interface 46. Then, the vehicle speed is stored in the internal memory during the -leg period, and a linear approximation calculation is performed using the data within that period, the data is compressed, and is recorded in the external storage device 24.

On the other hand, the processing device 18 and the external storage device 24 are connected by a control bus, a data bus, and an address bus.
The disadvantage is that it requires a special type of connection, and it is difficult to connect and disconnect the connector part. It's a place.
Contact type connectors require mechanical strength and have the disadvantage of being bulky. Therefore, in order to improve these drawbacks, a serial transmission method using optical communication in the connection part has been proposed.

According to this serial transmission method, processing device-18, L-
The number of signal lines required between the board recorder and the 24 is two in total, one for sending data and one for receiving data, and the connection uses optical communication. The external storage device 24 can be easily connected and removed, and the structure is simple. However, this serial transmission method is
It takes more than 100 times the time to transmit a byte of data compared to the conventional bus method, and it takes more than 1000 times -4g to record the same information in the external storage device 24 using the same method. There were drawbacks.

- Also, in the conventional serial transmission system, as shown in FIG. The system determines whether or not the system is in a state where it can receive data, and sends a reception start signal 74 to the transmission system to start transmitting data. When transmitting data from the transmitting system, following the flag 76 indicating the start of the data to be transmitted, the address 78, the number of data 80, and a large number of transmitting data 82 are sequentially sent to the receiving system, and finally the check code 83 is sent to the receiving system.
is sent to the receiving system. The receiving system stores the sent data in the specified address, receives the check code and checks it, and then sends the reception completion fg number 84 to the transmitting side, completing the data exchange. In this driving recorder, since the processing device 18 takes in the data and performs all the data compression, the amount of data to be transmitted to the external storage device 24 is large, and as the amount of data increases, the data is transmitted serially. If there is a large amount of time, there is a possibility that calculation processing cannot be performed during the fixed time T indicated by MiJ.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle operation recorder that can reliably record the speed at the time of an accident and can speed up data transmission.

[Summary of the invention]

The first aspect of the present invention is to sample data detected by a vehicle speed sensor and an engine rotation sensor at predetermined intervals using a sampling means, sequentially omit the sampled data τ to an external storage device, and compress the data. A data erasing means is provided in the data recording means for recording the data compressed by the means in the external storage device, and after the data compression means finishes compressing the data, the sampling data is sequentially erased, and the operation recorder is deleted at any point in time. Even if the power is turned off, the vehicle speed data at the time the power was turned off remains in the external storage device.

Still, the second aspect of the present invention is to provide a data compression means and a data recording means in an external storage device, and to sequentially transmit data from the vehicle speed sensor and engine rotation speed sensor sampled by the sampling means to the external storage device via a serial transmission device. Now, on the external storage device side, data compression and recording after data compression are performed, and the data compression means is used to provide a control means for the serial transmission device to perform smooth serial transmission, and to decentralize arithmetic processing. This configuration is designed to speed up data transmission.

[Embodiments of the invention]

A preferred embodiment of the vehicle operation recorder according to the present invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals are given to the parts corresponding to the parts explained in the prior art, and the explanation thereof will be omitted.

FIG. 10 shows a block diagram of an embodiment of a vehicle operation recorder according to the first aspect of the present invention.

In FIG. 10, the vehicle speed sensor 12 is electrically connected to counters 86 and 88 via an amplifier 38 and a comparator 40. Counters 86 and 88 are connected to MPU 44 via I10 interfaces 90 and 92. The engine rotation speed sensor 16 is connected to a counter 94 via an amplifier 30 and a comparator 32 (not shown in FIG. 10), and can input data to the MPU 44 via a 10 interface 96. Note that the symbols 98, 100, and 102 shown in FIG. 10 are I10, respectively.
It is an interface.

The external storage device 24 has a BJAM puncture, which is a cassette board with a large number of R and AM arrays, and can be detachably attached to the processing device 18.

As shown in Figure 11, the ram back has an operation data recording area 1 that records operation data such as date, car number, and work items.
04, a sampling data recording area 104 for recording sampled vehicle speed data, and a compressed data recording area 106 for recording compressed data. After the signal is amplified by the amplifier 38, it is shaped by the comparator 40, and then sent to the counters 86, 88.
(cackling). The counter 86 is connected to the real time generating circuit 5
The MPU 44, which received the signal at clock 1 of 0, issues a command to the I10 InternoAce 90 to clear σ at regular intervals, and vehicle speed information can be obtained. Further, the counter 88 counts the vehicle speed sensor No. 1g while the driving recorder is in operation, and provides distance information. These vehicle speed information,
The distance information is taken into the MP'U 44 via the ■10 Intern Ace 90°92. Similarly, the signal from the engine speed sensor 16 is also counted by the counter 94 and taken in to the MPU 44 via the I10 interface 96. Furthermore, information on work distinctions such as running and resting is inputted into the data input device 20 by manual operation by the driver.
This is also MPU44 via I10 Intern Ace 98
Q and C are included. The information received by the MPU 44 is displayed on the display device 22vC via the I10 interface 100 as necessary. The external storage device 24 is connected to the analyzer VC on the ground side at the end of one day's operation, and the operation data is reproduced there.

As shown in FIG. 12, the MPU 44i determines in step 108 whether the distant relative sampling time is old? to decide. Then, when the quick sampling time is reached, step 11
In Step 1, the data from the vehicle speed sensor 12 is taken in every predetermined period (for example, 0.2 seconds) in Step 1.
At 12, the sampling boot roller is inserted into the sampling data recording area 104 of the loss W pack. Then, if the predetermined time T has elapsed and it is not the speed sampling time, the process proceeds to step 114, where the sampling data d
Data compression processing is performed based on the sampling data recorded in the self-recording area 104, and when the data compression processing is completed, the compressed data is written in the compressed data i self-recording area 106 of the RAM pack in step 116. When writing of compressed data is completed, MPU
44 proceeds to step 118, erases the data stored in the sampling data recording area 104, and starts sampling the next data.

As described above, in this embodiment, the amount of data stored in the RAM pack can be reduced, and instantaneous single-speed recording can be performed digitally using a RAM pack with less memory dispersion. Moreover, the data sampled by the MPU 44 is recorded in the AM pack 44, so even if the driving recorder itself is damaged during a vehicle accident, the data at the time of the accident will be retained as long as the RAM pack is not destroyed. you can get
The original function of the driving recorder can be fully demonstrated.

FIG. 13 is a block diagram of an embodiment of the driving recorder according to the second embodiment of the present invention. In FIG. 13, M of the processing device 18
PU44 is a serial communication interface.
It is connected to an external storage device 24 via a chair (hereinafter referred to as SCI) 120 and an optical communication connector 122.

The external storage device 24 has an MPU 124 that operates the SCI 126 to receive data from the processing device 18 . Also,'.

The MPU 124 has a read-only memory (hereinafter referred to as I) in which a microprogram for operating the MPU 124 is stored.
(also referred to as OM) 128 and l (AM 130 and an IC memory 132 for data recording) are connected via a bus.

In this embodiment, which is configured as described above, the processing device 18 inputs data from the 5C1120, the original 1g, and the A transmission start signal 134 is sent to the external storage device 24, which is a receiving system, via the connector 122. When the external storage device 24 receives the transmission start signal 134, the MPU 124 determines whether the external storage device 24 can receive the transmission.
determines that it is possible to receive the reception start signal 136, and sends the reception start signal 136 to the MP
U124 sends it to the processing device 18 via 5C1126. Upon receiving the reception start signal 136, the processing device 18 outputs a flag 138, a data signal 140, and a check signal 142.
are sequentially transmitted to the external storage device 24. Then, the external storage device 24 receives the check mark 142, and when the check is completed, sends a reception completion signal 146 to the processing device 18, thereby completing the data exchange.

When the MPU 124 of the external storage device 24 receives the flag 148 from the processing device 18 as shown in FIG. 15, it determines whether the sent data is engine rotation speed, vehicle speed, work or cargo information. . And MPU
124 is the vehicle speed and engine speed 11i in step 136 when the sent data is the engine speed.
13. The gear position is determined by referring to the sensor and a gear position table stored in the ROM 128 in advance.

Thereafter, the MPU 124 determines whether the gear position determined in step 138 is the same as the previously determined gear position. If the requested gear position is the same as the previous time, it is not recorded; if it is different, it is recorded in the IC memory 132 along with the engine rotation speed data and time, and the engine speed is calculated and the engine is operated at the appropriate gear position. This is considered to be the material used to determine whether or not it was done.

When the data 140 sent to the external storage device 24 is vehicle speed data, the MPUI 24 temporarily stores the data in the AM 130 in step 142, and
In step 144, the MPU 124
It is determined whether or not one time period T has elapsed, and the vehicle speed data sent from the housing after a certain period of time T is sequentially recorded in the AM 130. When the time T ends, the data is compressed in step 146, and the compressed data is recorded in the IC memory 132.

On the other hand, work and cargo information are temporarily recorded in the RAM 130 for a predetermined period of time as shown in step 148, and then
After the U 124 determines whether or not the predetermined length of reception has been received in step 150, the process proceeds to step 15 after the reception is completed.
2, the work information and cargo information are recorded in the IC memory 132.

In this way, by sequentially transmitting the vehicle speed data, engine rotation speed data, work data and cargo data sampled by the processing device 18 to the external storage device 24, the number of data to be transmitted to the external storage device 24 is significantly reduced compared to the conventional method. do.

Moreover, the data calculation processing that was conventionally performed in the MPU 44 of the processing device 18 is performed by the MPU of the external storage device 24.
Processing device 18 by having it performed at 124
It is possible to reduce the arithmetic processing time in the processing device 18, prevent time management caused by the overhead of transmission time caused by serial transmission, and prevent the loss of vehicle speed data.
The reliability of compressed data can be improved by standardizing the processing and normalizing data sampling.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reliably record the speed of a vehicle at the time of an accident, and it is also possible to increase the speed of data transmission between the processing device and the external storage device.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram for calculating speed errors due to sampling of vehicle speed data, Figure 2 is an explanatory diagram of the data interpolation method, Figure 3 is a conceptual diagram of the configuration of a vehicle operation recorder, and Figure 4 is a diagram of the vehicle speed sensor. A detailed block diagram of the engine rotation speed sensor, Fig. 5 is a block diagram of a conventional vehicle operation recorder, Fig. 6 is a diagram showing an example of the processing procedure of the data interpolation method, and Fig. 7 is a diagram of the data interpolation method. Figure 8 is a diagram showing the relationship between conventional data compression processing and recording of data in RAM back; Figure 9 is a diagram showing the method of sending and receiving data in the conventional serial transmission method; Figure 8 is a diagram showing another example; FIG. 10 is a block diagram of an embodiment of the vehicle operation recorder according to the first aspect of the present invention, and FIG. 11 is a block diagram of the RAM in the external storage device of the vehicle operation recorder according to the first aspect of the present invention.
FIG. 12 is a flowchart showing an example of the data processing method of the vehicle operation recorder according to the first aspect of the present invention, and FIG. 13 is a diagram showing an example of the recording area of the pack. FIG. 14 is an explanatory diagram of an embodiment of the data transmission method to the external storage device of the vehicle operation recorder according to the second aspect of the present invention, and FIG. Second
3 is a flowchart of a data processing method of an external storage device of a vehicle operation recorder according to the present invention. lO...Vehicle, 12...Vehicle speed sensor, 16...Engine rotation speed sensor, 18...Processing device, 20...
Data input device, 22...Display device, 24...External storage device 44.124...MPU, 48...Internal memory, 50...Real time generation circuit, 120, 126...
・S'CI, 128...ROM, 130...RAM
, 132...IC memory. Agent Patent Attorney Tatsunokyo Unuma 1 (121 Rod 20 27' 30th 40th 2 Hana 60 Kayaoguchi 2 Hitsuji 70 30th ¥-90 Mine/θguchi Kaya I+ [2] l゛: Banae No. 120'j , 130V/4th district

Claims (1)

[Claims] 1. Sampling means for sampling data detected by a vehicle speed sensor and an engine/engine rotation speed sensor at predetermined intervals; and a plurality of samplings from the vehicle speed sensor sampled by this sampling means. In a vehicle operation recorder comprising a data compression means for compressing data at predetermined time intervals, and a data recording means for recording compressed data compressed by the data compression means in an external storage device; data 1 loading means for sequentially loading the sampling data into the external recording device; and data erasing means for erasing the sampling data after the data compression means provided in the data recording means has finished data compression. A vehicle operation recorder characterized by comprising the following. 2. Sampling means for sampling the data detected by the vehicle speed sensor and the engine rotation sensor at predetermined intervals; and sampling data from the vehicle speed sensor sampled by the sampling means at predetermined times. data compression means for compressing the data compressed by the data compression means in an external storage device; In a vehicle operation recorder, the vehicle operation recorder has: an information writing means to be omitted into the device; the data compression means and the data recording means are provided in the external storage device, and the data compression means controls the γ real transmission device. A vehicle operation recorder characterized in that it has a serial transmission control means.