JPH07104167B2 - Car driving guide device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle traveling guide device effective for traveling on an unguided road.

There are inertial navigation navigators, etc. that have enough accuracy to be able to collate with a map from those that show the direction and distance of the destination to the navigator for automobiles that guides the traveling to the destination, but both are preset before traveling, or It is necessary to prepare for azimuth setting, etc. after a little driving or planning. However, it is troublesome to make such a setting each time you drive a car, and with the setting method, you do not have to set up a guide device on a familiar road, so you can run without setting it, and if you get lost on the way, you need it. There is a problem that it is useless because it has not been set.

There is a compass that uses geomagnetism as a method that does not require presetting, and this has the advantage that it is simpler and cheaper than methods that use broadcasting waves, satellites, and the like. Moreover, in Japan,
It fits within a deviation angle of about 6 °, and there are few errors due to regional differences.
Even in a foreign country, such as the United States and Canada, where the deviation angle is large, the deviation angle is unlikely to change significantly when considered in a small range.

However, if a geomagnetic sensor is used as an azimuth meter,
In automobiles, the disorder of the ground caused by the iron part of the car becomes a problem.
This has a complicated error-azimuth characteristic that cannot be calibrated, and the azimuth error may reach 30 °, which makes setting the sensor attachment part difficult. In addition, there are cases where the entire bridge is magnetized by sections on elevated roads, iron bridges, etc., and when passing through electric railways and laying cables, automobiles may be magnetized, and the geomagnetic sensor is affected by these. Therefore, it is almost impossible to obtain the accuracy enough to reproduce the map based on the sensor output and the traveling distance even if the correction is finely performed. Therefore, when the vehicle starts traveling to the destination only by instructing the direction and distance to the destination or the direction distance from the starting point by the computer, the error becomes larger as the vehicle gets closer to the destination, which is not practical. The error will be small if calibrated during driving, but this is not practical for the driver.

Usually, the current position of the vehicle becomes uneasy after a certain amount of straying, and it is after that that the existence of the guide device is remembered. It is always taken and it is important to be able to retrieve it when needed. In this respect, the guide device operates when the key switch of the vehicle enters the position of an accessory switch such as a clock or a radio, and it is necessary to continue data collection and recording regardless of whether the vehicle is stopped or coasting. In addition, even if the key switch is in the off position, it is not practical because there are problems such as handle lock and battery exhaustion.

Moreover, the normal use of an automobile is to make a round trip between fixed grounds, and to drive an unguided road is a special case such as delivery or mountain climbing. In the former case, the guide device is not necessary, and the guide device is needed only in the latter case and when the user is lost. Therefore, it is sufficient for the guide device to be inconspicuous on a daily basis. Therefore, for example, it can be stored and recorded in this state, old data can be discarded and updated to new data, and new data can be immediately retrieved when necessary. Is desirable. For this type of purpose, a magnetic memory, a semiconductor memory or the like, which can be erased and rewritten many times, is suitable.

Recently, micro-processors (MPUs) and large-capacity RAMs have become available at low prices. Furthermore, the direction sensor technology using a magnetic valve has advanced, and it has become possible to manufacture an accurate and inexpensive direction sensor. The sensor using geomagnetism has the above-mentioned drawbacks, which can be covered to a considerable extent by the following method.

Even with a sensor that uses geomagnetism, it is sufficient to allow an error of ± 30 °.
Moreover, this error is fixed as a vehicle-specific error, and does not suddenly change (jump) to large or small. Therefore the instructions are continuous. In addition, the error due to the magnetization of a building or the like has a property that it is canceled out before and after passing through and becomes almost zero. Therefore, if the data collection interval is appropriate and only the data of a relatively short distance from the current position, but of a sufficient length (for example, 20 km) to find the road that has passed on the map, is used, The recorded data is sufficiently practical. It is normal for the driver to have some memorable things when going back about 20km. For example, I often get lost when I enter a small path, but since the point I entered the small path from the highway is in my memory, I search for that point on the map, and if I add the route indicated by the stored data from that point, the current position will be found. It Of course, the route indicated by this recorded data is not very accurate, but since it is shown roughly, it is possible to find roads and points on the map that are close to it.

The intersection angle of the road is often 70-110 °, and even a special one such as a 5-way intersection has an angle difference of 30 ° -40 °, so it is easy to find out which road you entered later from the recorded data. . Further, the geomagnetic deviation inside the vehicle that occurs at an inclination of 5 ° may give a heading error of about 10 °, but it is within the range where the bend of the road can be sufficiently discriminated. Also, if the automobile is subjected to extreme artificial magnetization, the sensor pointer will be fixed in a certain direction, but this will naturally be demagnetized within a few days. Whether or not it is unusable due to extreme magnetization can be self-diagnosed by driving a car and observing the movement of the pointer. Also, unlike radio waves, geomagnetism can be measured even in iron bridges and deep tunnels, and no significant error occurs.

The present invention has been made based on such knowledge, eliminating the drawbacks of conventional devices, eliminating the need for presetting and calibration,
Do not forget to switch it on so that the error is small,
It is another object of the present invention to provide an automobile travel guide device that allows the current position of the own vehicle to be immediately known accurately and is sufficiently practical.

The present invention relates to an azimuth sensor utilizing geomagnetism, a memory in which azimuth data detected by the azimuth sensor is written for each unit traveling length of an automobile, and old data is updated with new data when the stored data reaches a predetermined amount. What is claimed is: 1. A vehicle driving guide device comprising: a display unit that performs a display based on data written in a memory; and a main body having an information processing control processor, wherein the information processing control processor is written in the memory. The bending angle detecting means that constantly obtains the bending angle based on the amount of change in the data, and the point having the largest amount of data change among the bending angles detected by the bending angle detection means is the representative point of the bending angle, and the representative of the latest bending angle. And a means for displaying the traveled distance from the point to the present point on the display device.

In the present invention, an azimuth sensor using geomagnetism is used, and an error is recognized from the property of the sensor, and the azimuth can be erased and rewritten at a predetermined length, for example, every 10 m, based on the traveling distance at which a relatively accurate value can be obtained. The data is recorded in a memory, and if the distance is 20 km or less from the current position, the new data is updated.

As a result, a running locus of only the nearest predetermined km (20 km in this example) can be obtained, and a locus that is sufficiently practical even when using a direction sensor using geomagnetism is automatically obtained during running without the need for presetting. .

In addition, it is important to understand the corners to prevent lost children. For this reason, if the direction in which the vehicle bends at the turning angle and the distance traveled from it are automatically displayed, it becomes easy to find the current position of the vehicle on the map when it seems that the user has lost his way. Next, the present invention will be described in detail with reference to examples.

FIG. 1 is an external system diagram of a traveling locus recording apparatus according to the present invention. 10 is a geomagnetic direction sensor, 12 is a main body having an indicator and a processor, 14 is a dot printer, and l ₁ and l ₂ are main body 12. A conductive wire connecting the sensor 10 and the printer 14, l ₃ is a conductive wire to a battery of a power source, and l ₄ is a propeller shaft of an automobile or a flexible wire for rotation transmission to a mileage diameter. The front panel of the main body 12 has a display unit 16 and operation button group 18, and the display unit 16 has a large number of light emitting elements 20 arranged at equal intervals around a circular frame, and these are lit to indicate the traveling direction. . There is a rectangular frame in the center of the circular frame, in which a mark 22 indicating the direction bent at the previous intersection and a numeral 24 indicating the distance traveled from that mark are displayed. As the display device, an appropriate device using a light emitting diode, a fluorescent display lamp or the like can be used, but a device having a memory function such as a plasma display panel or a chemical particle electrodeposition display is also suitable. 26 is a mounting bolt. The operation button group 18 is made up of a key group for inputting any landmarks such as shrines and temples on the road that has just passed.

In the present invention, the azimuth data at that time is automatically written into the memory by the processor for each suitable traveling length such as 10 m, 20 m, or 40 m. As the azimuth data, 0 ° to 360 ° obtained by measurement is represented by 0 to 31 (or 0 to 63 in units of 5 °) indicating a unit of approximately 10 °, and the binary 5 (6) bit is 1 Write to byte / address RAM. This writing situation is shown in FIG. Address counter is hex display 00
It starts from 00 and increments by 1 each time one data is written. In this example, 07
When it reaches D0 (2000), it returns to 0 and updates old data with new data. The upper 3 (2) bits of each address, each having a storage capacity of 1 byte, are for writing the time, turning angle, and specific target, and are written when the operation push button 18 is pressed. The type is 4 or 8 in 2,3 bits, but if the specific contents are sequentially written in a specific address of the RAM, detailed time data and reference information will be obtained later.

Note that 0000 to 0800 on the left side of FIG. 2 are memory addresses represented in hexadecimal notation, and 7,6,5, ... 0 on the upper side are each bit or digit (least significant bit) of this memory of 1 address 8 bits. The bit is 0 and the most significant bit is 7.) As shown with diagonal lines, 5 bits for 32 divisions, 6 for 64 divisions
The bit angle data is written in 4th to 0th digit or 5th to 0th digit. 07D0 is the final address of the angle data recording area, and after this address, the flag (FLAG) and the angular difference (SP-1u) between the above-mentioned two predetermined angle data are written up to the memory final address 0800.

The bend angle is detected by taking the difference. For example, record every 10m,
At the current address 0405, 0 at 5th address (hence 50m before)
If the difference between the angle data at address 400 and the angle data at address 0405 is taken and it is 45 ° (if 360 ° is divided into 32, this is a numerical difference of 4, and if divided into 64, the same is 8) It is determined that there is a bend, and the point having the largest angle change is set as the center of the bend (representative point). To do this, the difference between the angle data of adjacent addresses 0405 and 0404, 0404 and 0403, and so on can be calculated to find the maximum. Since this is always done, it may not be possible to know whether the obtained difference is the maximum or not by looking at the next data, but if this is the maximum between 405 and 404, this is 405 and its corner. Write the difference to another address in RAM, find the difference in the angle data at the next address 406, update it as it is if it is small, and 406 and that angle if it is large, and repeat this process for accuracy. be able to. Right and left turns at intersections can usually be determined by checking the angle data within a running distance of 70m.

When the difference from the address before 5 is less than 45 °, it is judged that the bending is completed, and thereafter, preparation for detection of a new bending (the flag is set as such). If the difference is less than 45 ° and the difference is the same, record the newest data address and the difference. If the flag disappears and there is no turning in the direction of 50m or more than 45 °, straight running is performed, the display is changed as such, and the running distance from the center of the above-mentioned turning angle (if the unit is 10m, the difference between the addresses is 1
0 times) is displayed on the display unit 16. If the turn mark is a right turn This can be determined by the polarity of the difference in the angle data.

The data recorded in the memory RAM is read out when necessary.
The graph is displayed by the printer 14. This memory reading is performed while subtracting one address from the latest address, and the read data is a direction vector with a constant length (for example, 10 m above), so it is decomposed into sin and cos components and X and Y coordinates are obtained. The locus is drawn by displaying and adding each data. ROM that stores the required data in advance for the disassembly
The ROM may be accessed by using the read data of 0 to 31 or 0 to 63 as an address. Table 1 shows part of the ROM contents when 0 to 360 ° is divided into 64, and Table 2 when it is divided into 32.

The angle data 0 is expressed as 0 for sin, 64 for cos (100 in decimal because it is hex), and minus is +80 (128 in decimal).

Every time the ROM data is read, it is added for each sin component and cos component,
Sequentially store the accumulated result in the distance data addition area of RAM,
Using this, the printer (XY recorder) 14 may be made to draw a graph (indicating the locus traveled from the current position to the present position). When writing on a printer, the angle is +16 (+
32) Use the one that has been reversed according to the one you have done. The stepper motor of the printer drives the head by performing the distance division (multiplying the mechanism coefficient according to the scale to determine the divisor) as is generally done.

FIG. 3 shows an electric system of the traveling locus recording device. The azimuth sensor 10 is of a magnetic valve type and includes an annular magnetic core 30 having a square hysteresis characteristic, an excitation winding 32 wound around the entire circumference of the annular magnetic core 32, and two orthogonally wound belt-shaped magnetic cores. The detection coils 34 and 36 are provided. Winding 32 moves magnetic core 30 to 4-8KH
When excited above the magnetic saturation point with an alternating current of z, the magnetic permeability is approximately 1 at the positive and negative saturation points, and the magnetic permeability becomes maximum (usually 2000 to 10000) at the point of zero magnetic flux in the middle, and the magnetic flux due to geomagnetism is the former. The minimum is 0, the maximum is the latter, and the excitation frequency is 4 to 8K.
It changes at the same frequency as Hz. This change in magnetic flux causes the coils 34,3
Since a voltage is induced in 6 and these coils have different 90 ° angles, one outputs the cos component of the magnetic field due to the geomagnetism and the other outputs the sin component. Reference numeral 38 is a drive circuit for the azimuth sensor 10, which amplifies the output of the frequency division counter 40, which is 4,096 KHz in this example, and supplies the amplified output to the winding 32 to excite it. The output e ₀ of the drive circuit 38 is a rectangular wave as shown in FIG.
This is effective in making the outputs e ₁ and e ₂ of 6 into peaks of appropriate sharpness. Reference numeral 42 denotes an azimuth sensor output synthesizer which has a resonator having a frequency twice the excitation frequency, receives the outputs e ₁ and e ₂ and generates a sine wave shown by a dotted line in FIG. 4, and advances one of them by 45 °. The other one is delayed by 45 ° and synthesized to make the sum e ₁ + e ₂ and the PLL
And so on, the positive half wave is shaped into a rectangular wave, and the output e ₃ is generated. 44 is a phase valve unit, making the output e ₅ in which the e ₃ to 1 divided by 2 minutes receiving an output e ₃ than or combiner the same square wave e ₀ from the dividing counter 40, and the output e ₄ than make. uses an RS flip-flop, for example, in the generation of e _5, this in-and output of the e ₀ obtained by inverting the e ₃ reset, e _0, e ₃ may be set at both and despite the inverted output. To generate e ₄ , just take the AND of e ₀ and e ₅ . The pulse width of the output e ₄ indicates the azimuth.
Expressed as the number of CLKs. Reference numeral 46 denotes an azimuth signal generator that performs this processing, and includes a gate that is opened / closed by the output e ₄ and a counter that counts the clock CLK passed through the gate. Clock c
The frequency of LK is 262,144 Hz, for example. This counter output S ₁ is given to the microprocessor and the I / O port 50 and written in the RAM 52 for each unit running length. Further, the counter output S ₁ is converted into a light emitting element drive signal of the decoder 48 display 16, and the light emitting element corresponding to the measured direction is turned on.
54 is a memory for storing the cos, sin data and the like, 56 is a display drive circuit with a latch circuit, and 58 is 4, 4 in this example.
A 194,304Hz crystal unit, 60 is a low-pass filter, and 62 is a reed relay that turns on and off according to the rotation of the propeller shaft of an automobile, which constitutes a travel distance sensor. The unit traveling length described above is obtained by counting the relay output pulses, and the traveling distance obtained by this counting is displayed on the traveling distance portion of the display unit 16 through the circuit 56. Also, W ・ AC in Fig. 4
K is a write pulse of RAM and is created by inverting e ₅ and AND with e _3. ER is a signal generated at the falling edge of W · ACK, which resets the latch circuit of output S ₁ in circuit 50 after writing is completed Used for.

FIG. 5 is a flowchart showing the above operation. (1), (2), ... In this figure correspond to 1, 2 ,. B of B1, B2, ... Shows blocks, therefore B1 is block 1, B2 is block 2 ,. In block 1, the starting point DE of the direction data writing area of the memory
Initially set to 0000 (hex), in block 2 every 10m, 2
It receives a distance input at every 0 m, every 40 m, etc., performs interrupt processing, and sets a flag indicating the distance pitch. In block 3, contents of address counter SPC
Is incremented by 1 to set an angle (azimuth data) recording address. In block 4, SPC is the end of the direction data writing area 7
It is checked whether or not D0 (hex) has been exceeded, and if it exceeds, it is returned to the starting point 000 (hex) at block B5, and if not, it proceeds to block 6. In block 6, azimuth data, that is, angle information is input, and in block 7, it is checked whether or not there is a key input (symbol signal) from the operation button group 18, and if there is, the contents (shrine, temple, etc.). Is determined by a flag, it is set in the upper 2 digits of 8 bits, and it is added to the angle signal of the lower 6 (5) bits. Symbol signal = 3 is the time, and in this case (Yes in B9), the address ADR indicated by the symbol signal pointer MP
Then, record the hour and minute in the address that is +1 and add 2 to MP (B10). In block 11, the presence / absence of the above-mentioned symbol signal is checked, and in block 12, if there is a symbol signal, the pointer MP is decremented by -2. In block 13, the symbol signal and the azimuth signal are recorded in the memory address indicated by SPC.

In block 14, 1 or 6 bits or 5 bits of azimuth signal
2 and cut off the least significant bit, and the fifth digit in block 15 is 1
In the case of, the last four digits are latched as an angle signal to the input / output port (I / O port), and the light emitting element 20 of the display 16 indicates the traveling direction. In block 16, memory addresses SP and SP-i
(In this case, i is 5, if the distance pitch DP is 10m, 3, 40 if it is 20m.
If m, the difference is 2), that is, the difference between the azimuth data, and if this is 8 (corresponding to 45 ° in the case of 64 divisions) or more, it is determined as a bending angle, and the center (representative point of the bending angle) is obtained in block 17. For this, i is decreased by 1 and SP- (SP-i) 6
Find i at (about 34 °) and write the address in the corner memory. Then, in block 18, the flag is set as such in preparation for detection of a new bend, and if it is determined in block 16 that it is not a bend, the flag is updated in block 19. Further, in block 20, the distance from the representative point of the latest turning angle is output as three digits (including a decimal point) representing 0.00 Km to 999 Km, and this is displayed on the numeral 24 of the display unit 16. In block 21, it is checked whether or not there is a printer operation instruction,
If there is, the printer is operated to plot the traveling locus.

As described above, in the present invention, the geomagnetic sensor and the circulation type memory are adopted, and the azimuth data storage for each constant distance, the data processing by the microprocessor, the control, the memory capacity is small, the high-precision data can be stored, No consumables,
It offers advantages such as smaller size and lower cost than those using cathode ray tubes. In addition, since the distance from the latest turn to the current position is automatically displayed on the display of the main unit, the destination has the advantage that you can easily find the destination when you bend the XX intersection and how many meters etc. is there.

Further, the present invention is not limited to simply detecting the corner angle,
Among the bends, the point on the map where the change in orientation data is the largest is specified as the representative point, and the distance from the representative point to the current position is displayed. is there.

[Brief description of drawings]

FIG. 1 is an external view of a device of the present invention, FIG. 2 is an explanatory diagram of memory contents, FIG. 3 is an electrical system diagram, FIG. 4 is a waveform diagram for explaining operation, and FIG. It is a flowchart shown. In the drawing, 10 is an orientation sensor, 12 is a main body, 14 is a printer, 16
Is a display and 52 is a memory.

Continuation of the front page (56) References JP-A-57-73500 (JP, A) JP-A-57-73498 (JP, A) JP-A-50-67672 (JP, A) Actual development Sho-56-107516 (JP , U) Actual exploitation Sho 57-16914 (JP, U)

Claims (1)

[Claims] 1. An azimuth sensor utilizing geomagnetism, and a memory in which azimuth data detected by the azimuth sensor is written for each unit traveling length of an automobile, and when the stored data reaches a predetermined amount, old data is updated with new data. An automobile driving guide device comprising: a display unit for displaying based on data written in the memory; and a main body section having an information processing control processor, wherein the information processing control processor writes in the memory. And a bending angle detecting means for always obtaining a bending angle based on the amount of change in the data, and a point having the largest amount of data change among the bending angles detected by the bending angle detecting means is set as a representative point of the bending angle, A vehicle traveling guide device, comprising: means for obtaining a traveling distance from a representative point to a current point and displaying the traveling distance on the display.