JPH02301888A - Digital tachograph - Google Patents

Abstract

PURPOSE:To evade a write operation beyond memory capacity by issuing an alarm from an alarm means when the remaining memory capacity of an insertible/extractable storage medium shows a value less than a prescribed value in a digital tachograph main body. CONSTITUTION:A card insertion opening 3 is formed at the front plane of the digital tachograph main body 2 formed in box shape, and a memory card 4 as the recording medium can be inserted to and extracted from the card insertion opening 3. The total memory capacity of the memory card 4 is stored in part of the storage area of the memory card 4 in an ID code. An on-vehicle microcomputer reads the ID codes corresponding to all the memory capacity of the memory card 4, and the remaining memory capacity is found by subtracting the quantity in use of the memory from the total memory capacity value of the memory card 4 corresponding to a code number, and when the remaining memory capacity shows the value less than the prescribed value, an alarm lamp 7a is lit. Thereby, it is possible to evade the write operation beyond the memory capacity.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a digital tachograph.

[Prior Art] Conventionally, analog graphs recorded travel speed, engine speed, distance traveled, etc. on continuously rotating recording paper. In contrast, digital tachographs record these data while sequentially lean-pulling them. As a storage medium for this data, there are storage media that can be inserted into the digital tachograph body, such as memory card 1-, memory card 1-ridge, memory card, I
It is considered that a C card or the like may be used.

[Problems to be Solved by the Invention] However, these storage media have various storage capacities, and in order to reduce the cost of the system, it is desirable to configure the system with a storage capacity as small as possible. Therefore, the user ends up using the storage capacity to its limit, and in the worst case, there is a problem in that an attempt is made to perform a write operation that exceeds the storage capacity, resulting in a system error.

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital tachograph that can very easily detect a decrease in the remaining capacity of a storage medium and can avoid writing operations that exceed the storage capacity.

[Means for Solving the Problem] This invention provides a digital tachograph body that is mounted on a vehicle and that leanbrings vehicle speed data from a vehicle speed detection means at predetermined time intervals and stores changes in vehicle speed as digital values; In the digital tachograph comprising a storage medium that can be inserted into the digital tachograph main body, the entire storage capacity data of the storage medium is stored in advance in a part of the storage area of the storage medium. A digital tachograph that reads all storage capacity data, determines the remaining storage capacity of a storage medium at that time based on the total storage capacity data, and issues an alarm using an alarm means if the remaining storage capacity is less than a predetermined value. It covers the gist.

[Operation] The total storage capacity data of the storage medium is stored in advance in a part of the recording/upper area of the storage medium, the total storage capacity data of the storage medium is read out, and the data is calculated based on the total storage capacity data. The remaining storage capacity of the storage medium at that time is determined, and if the remaining storage capacity is greater than a predetermined value, an alarm is issued by the alarm means.

"Embodiment" Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.

FIG. 2 shows the digital graph 1 of this embodiment.
A card insertion slot 3 is formed on the front side of the digital tachograph main body 2 which is formed into a box shape.

A memory card 4 as a storage medium can be inserted through this card insertion slot 3.

Further, various operation switches 5a to 5f are arranged on the front surface of the digital tachograph main body 2.
Data such as the start and end of the operation can be entered by operating f. 3. A display device (5) is provided on the front of the digital tachograno main body 2, and this display device 6 displays information such as the time and vehicle speed. Data is displayed.In addition, lamps 7a to 70 are arranged on the front of the digital tachograph body 2, and the lamp 7a is used as an alarm means to warn that the remaining storage capacity of the memory card 4 is below a predetermined value. It is used as a warning lamp.

FIG. 3 shows the electrical configuration of the digital tachograph. The digital tachograph main body 2 has a built-in microcomputer (hereinafter referred to as an on-vehicle microcomputer) 8, and a vehicle speed detector 10 as a vehicle speed detecting means is connected to the on-vehicle microcomputer 8 via an interface 9. Further, the on-vehicle microcomputer 8 operates at 1 o'clock by the pulse signal from the oscillation circuit 11, displays the time on the display device 6, and
The detection signal from the vehicle speed detector 10 is limbered at predetermined intervals to determine the vehicle speed.

The in-vehicle microcomputer 8 has a card write/read buffer 12.
is connected, and the buffer 12 is used to write data (digital values) indicating changes in vehicle speed to the memory card 4 and to read the written data. Further, the in-vehicle microcomputer 8 is connected to each runshift E] to 7C including the alarm runshift a. In general, the operation signal for the ignition switch 14 is input to the small gun mine 1/ε3 via the interface 13, and the same signal causes the ignition switch 1/1 to be activated. Detects whether the is turned on or off. The vehicle-mounted mini-con B receives a constant voltage power source from an external power supply device 16 via an interface 15. Further, the in-vehicle microcomputer 8 manually inputs operation signals from the operation switches 5a to 5f.

The in-vehicle microcomputer 8 records driving data based on the signal from the vehicle speed detector 10 on the memory card 4, but a part of the storage area of the memory card 4 contains B of all data on the card.
A storage area is prepared for storing the CC value (B]21Tsukuchi] - Tsuta1 - Yarakuta value). When the memory card 4 is handled from the digital tachograph main body 2, the in-vehicle microphone 8 calculates the BCC value and it becomes piled up in a predetermined area. In a part of the storage area, an area is prepared in advance in which the entire storage capacity ω of this memory card 4 is stored as an ID code.

FIG. 4 shows a device for reading data stored in the memory card 4 and processing the data to perform various processes. This equipment is installed indoors. In addition, FIG. 5 shows the electrical configuration of this ground-side equipment. , a card reader/writer 21, and a printer 22 are connected. Then, the ground side computer 18 is a card reader.
The data stored in the memory card 4 can be read by the writer 21 and displayed on the display 19 or printed by the printer 22.

Furthermore, data can be input to the ground-side computer 18 using the keyboard 20, and the ground-side computer 18 drives the card reader/writer 21 to write data to the memory card 4. Using this keyboard 20, a portion of the storage area of the memory card 4 can be pre-assigned to the memory card 4.
The entire storage capacity of is now stored in ID codes.
There is C. That is, before using the memory card 4, insert the memory card 4 into the card reader/writer 21, turn on the system power, write the ``Fi'+-ID21-'' code to a predetermined address, and then turn the system power on. This is done by turning off the memory card 4 and removing it from the card reader/writer 21. Note that if the memory card 4 has a configuration that allows it to be handled as a live wire, the memory card 4 can be removed without turning off the system power.

Next, the operation of the digital sea urchin graph constructed in this way will be explained.

FIG. 1 shows a routine for determining the remaining storage capacity of the memory card 4 and issuing an alarm if the remaining storage capacity is less than a predetermined value. First, in step 100, the in-vehicle microcomputer 8 selects an I
The D code is read, and in step 101 the memory usage is subtracted from the total storage capacity value of the memory card 4 corresponding to the code number to determine the remaining storage capacity. moreover,
The in-vehicle microcomputer 8 determines whether the remaining storage capacity is less than a predetermined value in step 102, and if it is less than the predetermined value, the process proceeds to step 1.
At 03, the alarm lamp 7a is turned on.

FIG. 6 shows a data write check routine for checking whether the memory card 4 is operating normally or not by the in-vehicle microcomputer 8. Automotive microcontroller 8 is step 2
00', the data is stored in a predetermined location on the memory card 4. Then, the in-vehicle microcomputer 8 reads the data written to the memory card 4 in step 201, and then reads the data written in the memory card 4 in step 202.
The first data is compared with the read data to determine whether they match. If they match, the on-vehicle microcomputer 8 determines that the addresses are normal, but if they do not match, the address is made unusable in step 203 and is stored in another normal address.

FIG. 7 shows a check routine for checking whether the data on the memory card 4 by the combination coater 18 on the ground side is normal or not.

The ground-side computer 18 reads data from a predetermined address of the mail card 4 whose data contents are known in advance in step 300, and determines in step 301 whether the read data matches the predetermined data known in advance. to judge. If there is a mismatch, the ground computer 18 determines in step 302 how many times the current mismatch has occurred, and if it is the first time, the process returns to step 300 and processes steps 300 and 301 again. Ground side combination”−
When the second discrepancy occurs in step 302, the display 19 displays the following message in step 303.
The card data contains an error and cannot be accessed.'' is displayed.

Furthermore, when the data read out in step 301 and the predetermined data match, the ground side computer 18 reads out the other data in the memory card 4 in step 304 and calculates the f3 CG value (block check character value) of all the data in the memory card 4. ).

Subsequently, in step 305, the ground-side computer 18 uses the obtained BCC value and the BCC value stored in the memory card 4.
It is compared with the CC value to determine whether they match or not. and,
If the data match, the ground computer 18 determines that the data is normal in step 306 and adopts the data on the memory card 4. If there is a mismatch in step 305, the ground-side computer 18 determines how many times the current mismatch has occurred in step 307, and if it is the first time, returns to step 304 and reads out all data on the memory card 4 again, and in step 30
Perform the process in step 5. When the ground-side computer 18 detects a second mismatch in step 307, the ground-side computer 18 executes step 30.
At step 3, the display 19 displays the message "Card data contains an error and cannot be read."

In this embodiment, the customer traffic TD code corresponding to the total storage capacity of the memory card 4 is stored in advance in a part of the storage area of the memory card (storage medium) 4 using the keyboard 20, the ground computer 18, etc. The in-vehicle microcomputer 8 reads the capacity ID code of the memory card 4 (step 100), and calculates the remaining storage capacity of the memory card 4 at that time based on the total storage capacity corresponding to the code number (step 101). ), if the remaining storage capacity is less than a predetermined value, the alarm lamp 7a is lit to issue an alarm (steps 102 and 103).Therefore, conventionally, usage notifications indicate that when the storage capacity is used up to its limit, the storage capacity will be reduced. There was a risk that a write operation would occur over the memory card (storage medium).
If the decrease in the remaining storage capacity of 1 is known in a very simple manner, processing such as continuing data recording using a spare memory card becomes possible, and it is possible to avoid rewriting operations that exceed the storage capacity.

In addition, since the memory card 4 is used by the in-vehicle microcomputer 8 as shown in FIG. 6, and each address is checked to determine the presence or absence of an abnormality, reliability is excellent. J, sea urchin ground side computer 18 shown in the figure
Since the quality of the data in the memory card 4 is determined whether the data is good or bad, the reliability is excellent.

Note that this invention is not limited to the above embodiments,
For example, the storage medium may be a memory card or a memory card.
- It may be a storage device, a memory cassette, an IC card, etc. In addition to the total storage capacity, the driver's employee number and other ID numbers can also be written in the memory card 4, and the date and time of replacing the card battery can be written in advance and stored in the digital tachograph main body 2. It is also possible to set the card to 1 or more, and when the battery replacement date approaches, a warning may be issued immediately after the ignition switch is turned on.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to very easily know the decrease in the remaining capacity of a storage medium and to avoid writing operations that exceed the storage capacity. do.

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining the operation of the digital tachograph of this embodiment, FIG. 2 is a perspective view of the digital tachograph, and FIG. 3 is an electric circuit diagram of the digital tachograph.
FIG. 4 is a perspective view of the ground side equipment, FIG. 5 is an electric circuit diagram of the ground side equipment, FIG. 6 is a flowchart, and FIG. 7 is a flowchart. = 13- 2 is a digital tachograph body, 4 is a memory card as a storage medium, and 7a is an alarm lamp as an alarm means.

Claims (1)

[Scope of Claims] 1. A digital tachograph body that is mounted on a vehicle and that samples vehicle speed data from a vehicle speed detection means at predetermined time intervals and stores changes in vehicle speed as digital values, and is removable from the digital tachograph body. In a digital tachograph equipped with a storage medium, the total storage capacity data of the storage medium is stored in advance in a part of the storage area of the storage medium, and the total storage capacity data of the storage medium is read out. A digital tachograph characterized in that the remaining storage capacity of a storage medium at that time is determined based on storage capacity data, and when the remaining storage capacity is less than a predetermined value, an alarm is issued by an alarm means.