JP2000293225A - Position detecting device for self-traveling unmanned vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use the device irrelevantly to the magnetization polarity of a guide tape constituting a travel guide path by driving Hall elements which are arranged along the axis of the guide path in order, placing them in operation alternately, and extracting position detection signals. SOLUTION: The guide tape T constitutes the guide path which is magnetized to guide the unmanned vehicle to travel and the Hall elements H1 to Hn are arranged at a specific distance above the guide tape T so that they are isolated from one another along its width. A 1st switch PX1 to PXn and 2nd switches PX1' to PXn' are placed in operation alternately and sequentially in response to 1st and 2nd drive signals S1 and S2 to drive the Hall elements H1 to Hn in order, and their outputs are applied to an amplifier A1. The amplification output from the amplifier A1 is converted by an A/D converter from analog to digital and inputted to a CPU. The CPU compares the A/D-converted Hall- element outputs with a specific reference voltage and outputs position detection signals corresponding to the comparison results to output terminals CH1 to CHn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a position detecting device suitable for an autonomous traveling unmanned vehicle using a plurality of Hall elements.

[0002]

2. Description of the Related Art In a self-sustained traveling unmanned vehicle, a magnetized guide tape made of a magnetized body is run on a taxiway formed by affixing it to the floor so as to come on the taxiway. Some devices detect a relative position with respect to a taxiway using a position detecting device, and control the traveling of the vehicle according to the detection signal. In this case, the position detecting device includes a plurality of magnetic detecting elements (magnetic switches) that conduct in response to magnetism, such as a saturable coil, a Hall element, and an MR element, each of which is spaced apart from each other by a predetermined distance. One that detects the left and right positions in the width direction of the tape has been proposed.

For example, as a position detecting device using a saturable coil as a magnetic detecting element, Japanese Patent Application Laid-Open No. H10-1702 discloses a position detecting device.
No. 48 is known. Also, as a position detecting device using a Hall element as a magnetic detecting element,
The configuration shown in FIG. 5 is well known. 6, as shown in FIG. 6, reference numeral 1 denotes a plurality of Hall elements arranged in the width direction of a magnetized guide tape T as a traveling guide path of an unmanned vehicle, 2 denotes an amplifier, and 3 denotes a comparator. Are used in plurality corresponding to the Hall elements 1. 4 is a driving device including a power supply, 5 is an output connector, and 6 is a reference power supply. These components are usually arranged on one board.

[0004]

However, all of the conventional position detecting devices have a disadvantage that the manufacturing cost is increased for the following reasons. For example, in a position detecting device using a saturable coil or an MR element as a magnetic detecting element, it is not possible to distinguish between an N pole and an S pole with a magnetic field of the same strength.
It is necessary to prepare a magnetic detecting element for detecting the pole and detecting the south pole, which is expensive. Further, in a position detecting device using a Hall element as a magnetic detecting element, the Hall element itself is the same element and can detect the N pole and the S pole, and is inexpensive, but its output offset voltage varies with temperature. Large and not constant by element. Therefore, it is necessary to select Hall elements having uniform temperature characteristics, which requires a lot of time, resulting in an increase in manufacturing cost.

[0005] Further, the guide tape T is magnetized so that its surface becomes an N pole or an S pole, and the polarity of the magnetization varies depending on the guide tape and is not constant. Therefore, it is preferable that the position detecting device can be used for a guide tape of any magnetization polarity.

[0006] Conventionally, the deceleration in the unmanned vehicle traveling, stopping, separately installing a magnetic tape T _m for markers in the vicinity of the magnetic tape T ₁ guide 7 for timing determination branch T ₃ For this reason, it is necessary to provide the magnetic detection element 7 for marker detection separately from the magnetic detection element 1 for position detection, which is expensive.

A first object of the present invention is to provide a position detecting device which can be used irrespective of the magnetization polarity of a guide tape constituting a traveling guideway of a self-contained traveling unmanned vehicle.

A second object of the present invention is to provide a position detecting device which does not require the marker magnetic tape to be provided at a position different from the guide tape, and which does not require a marker detecting magnetic detecting element.

A third object of the present invention is to use, in the position detecting device, a magnetic detecting element such as a Hall element which is inexpensive but has a non-uniform temperature characteristic, and has a drawback of a temperature fluctuation of an output offset voltage. To economically and efficiently remove the effects of

[0010]

In order to achieve the first object, a position detecting apparatus for an independent traveling type unmanned vehicle according to a first invention is magnetized for guiding an independent traveling type unmanned vehicle to guide traveling. In a position detecting device for detecting a position of a taxiway in the width direction, a plurality of hall elements arranged apart from each other in the width direction of the taxiway, and first and second elements sequentially driving the hall elements. The gist of the present invention is to include a second driving unit and a control unit that operates the first and second driving units alternately to extract a position detection signal.

In order to achieve the second object, a second
In the position detecting device for an independent traveling type unmanned vehicle according to the invention, in the first aspect, the guideway includes a traveling portion and a marker portion magnetized between the traveling portion and having a different polarity from that of the traveling portion. The gist of the invention is that the control means determines the passage of the marker portion from the position detection signal obtained when the first or second drive means is operated and extracts the marker signal.

Further, in order to achieve the third object, a third
The position detecting device for an independent traveling type unmanned vehicle according to the invention of the first or second aspect, wherein at least one temperature detecting element and each setting of the Hall element in a magnetic field applied to the magnetic detecting element as a reference value Data writing means for detecting a temperature by the temperature detection element, and sequentially storing each output data of the Hall element for each detected set temperature in a predetermined storage means, and the temperature detection element stored when used. Reading means for reading output data corresponding to the temperature detected by the device, and output means for comparing the read output data with the output of the Hall element and outputting a detection signal according to the comparison result. Is the gist.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a position detecting device for an independent traveling type unmanned vehicle according to the first invention. In the figure,
H ₁ to H _n is a Hall element, MPX ₁ ~MPX _n first switching unit as the first drive means, MPX _'1 ~MPX' _n the second switching unit as a second driving means, A ₁ is an amplifier, and SCP is a single chip computer. CH
₁ to CH _n data output terminal, T is magnetized guide tape, single-chip computer SCP includes A / D converters AD _1, a random access memory RAM, read only memory ROM, and a central processing unit CPU or the like .

The guide tape T constitutes a magnetized guide path for guiding a self-supporting unmanned vehicle to guide and travel, and the Hall elements H _{1 to} H _n are located a predetermined distance above the guide tape T and extend in the width direction. Are spaced apart from each other.

The first switches MPX ₁ -MPX _n and the second switches MPX ₁ -MPX _n
Switchers MPX ′ _{1 to} MPX ′ _n are the _first switches from the CPU.
And in response to the second drive signals S ₁ , S ₂ , alternately and sequentially, respectively, to sequentially drive the Hall elements H _{1 to} H _n, and to sequentially apply the respective outputs to the amplifier A _1. . Amplifier A ₁
Amplified output from is A / D converted by sequential A / D converter AD _1, and inputs to the CPU. The CPU compares the output of each Hall element is A / D converted and a predetermined reference voltage, and outputs a position detection signal "1" or "0" corresponding to the comparison result to the output terminal CH ₁ to CH _n.

Since the output polarity of the Hall element is inverted between the case where the surface of the guide tape T has a magnetized polarity of the N pole and the case where the surface of the guide tape T has the magnetized polarity of the S pole, the second switching is performed. vessel can be taken out position detection signal even if either polarity by applying to the amplifier a ₁ inverts the output of the Hall element to the first switching unit. That is,
For example, when the surface of the guide tape T has the N-pole magnetized polarity, the first switching devices MPX _{1 to} MPX _n connect the Hall elements H
While sequentially take out the outputs of the ₁ to H _n, guide when the surface of the tape T is magnetized poles of the S pole, the second switching unit MPX _'1 ~MPX' _n Hall elements H ₁ to H _n sequentially taken out by reversing the polarity of each output is applied to the amplifier a ₁ in. With this configuration, the position detection signal can be obtained from the Hall element regardless of the magnetization polarity of the guide tape.

FIG. 2 shows an embodiment of a position detecting device for an independent traveling type unmanned vehicle according to the second invention. The same reference numerals as those in FIG. 1 denote the same or similar circuits. In the figure, M is a marker signal output terminal, and a guide tape T is, for example, as shown in FIG.
It is configured as shown in FIG. In FIG. 3, T ₁ , T ₂ , and T ₃ are running parts, _Tm is a marker part, and running parts T _{1 to} T ₃ have N surfaces.
Pole, indicating that the marker portion T _m surface are magnetized S pole, the marker portion T _m is the running portion T ₃ is a branch road.

In this case, the output (position detection signal) of the Hall element is taken out from the first switching device (driving means) when the traveling portions T ₁ and T ₂ are traveling, and the second switching is performed when the marker portion _Tm is traveling. The output of the Hall element is taken out of the vessel. Thus the CPU outputs a marker signal M to determine the passage of the marker portion T _m from the Hall element output obtained during the operation of the first or the second switching unit. In this case, since the output of the Hall element can be used as a position detection signal, it does not affect running performance. In addition, since the marker magnetic tape is not provided in the vicinity of the guide magnetic tape unlike the related art, it is not necessary to separately provide a marker detecting magnetic detecting element.

FIG. 4 shows an embodiment of the position detecting device for an independent traveling type unmanned vehicle according to the third invention. In the figure, H ₁ ~
H _n is a Hall element, MPX ₁ ~MPX _n first switching unit, MPX _'1 ~MPX' _n the second switching unit, A ₁ is an amplifier, TH ₁ is temperature detecting element, A ₂ is an amplifier, SCP Is a single-chip computer. The single-chip computer SCP includes A / D converters AD ₁ and AD ₂ , a read-only memory ROM, a random access memory RAM, a central processing unit CPU, and the like. CH ₁ to CH _n data output terminal, SW ₁ is data storage address setting switch, SW ₂ is the data acquisition start switch, SW ₃ is a mode changeover switch. The apparatus shown in FIG. 3 performs the following operations in the data collection mode and the operation mode.

[0020] switching the data collection mode when the mode selector switch SW ₃ to the data collection mode, to turn on the data collection start switch SW _2. Hall element H ₁ ~H
_The position detecting device incorporating _n is placed in a reference value magnetic field (for example, N pole 5 gauss) in a use state, and the surrounding temperature is sequentially changed stepwise (for example, -15, -10, -5 to -5 every 5 degrees).
Changed to 0,55 ° C.), the outputs of the Hall elements H ₁ to H _n when stabilized at the set temperature, the first switching unit MPX ₁ ~
Sequentially giving changeover switch drive signal from the CPU to the MPX _n, corresponding to the operation of the first switching unit is A / D converted by sending via the amplifier A ₁ sequentially switches the A / D converter AD ₁ memory It is stored in the ROM area.

Next, the magnetic field of the reference value is changed (for example, to 5 gauss S-pole), the ambient temperature is sequentially changed in the same manner as described above, and the second switches MPX ′ _{1 to} MPX ′ _n are sequentially changed. Switch and store the data in the corresponding memory ROM. At the A / D converted by the A / D converter AD ₂ via an output even amplifier A ₂ of the temperature detecting element TH ₁ at each set temperature simultaneously, the memory R in correspondence with the output data of the Hall elements
Store it in the OM. Data storage address in ROM at this time, the data storage address setting switch SW ₁ externally designated by like switching corresponding to each setting temperature. Thus for one set temperature, as shown in Table 1, each of the output data and the temperature detecting element TH ₁ of the Hall elements H ₁ to H ₁₀
Will be stored in the memory ROM correspondingly.

[0022]

[Table 1]

[0023] switched the time of the operation mode] mode switch SW ₃ to the operation mode. Detecting the temperature of the Hall element near the time of use by the temperature detecting element, by providing the CPU with A / D converted by the A / D converter AD ₂ via the amplifier A ₂ and the detection signal, CPU its detection The output data of each Hall element corresponding to the temperature is read from the memory ROM as comparison data and prepared. Then the output of the Hall elements H ₁ to H _n, the first and second switching unit MPX
_{1 ~MPX n,} sent to the A / D converter AD ₁ through the amplifier A ₁ are sequentially switched alternately by MPX _{'1 ~MPX' n} A
/ D conversion and input to CPU. The CPU compares the detection outputs E ₁ , E ₁ ′ of the respective Hall elements extracted by the first and second switches with the read output data E ₂ , E ₂ ′.
When sequentially compared, and outputs a detection signal corresponding to the comparison result to the output terminal CH ₁ to CH _n. For example, E ₁ ≧ E ₂ or E ₁ ′
If ≧ E ₂ ′, “1” is output, and if E ₁ <E ₂ or E ₁ ′ <E ₂ ′, “0” is output. Thereby, the influence of the temperature change of the offset voltage of each Hall element can be minimized.

Further, a memory ROM corresponding to each set temperature
The output data of each Hall element in not only includes the temperature fluctuation of the offset voltage of each Hall element, but also minimizes the influence of the fluctuation due to the temperature of all components constituting the position detecting device. It also contains components. Therefore, it is effective even when an element other than the Hall element is used as the magnetic detection element. In the above embodiment, the set temperature in the data collection mode is set to -15 to 55 [deg.] C. at 5 [deg.] C intervals.

In the data collection mode of the above embodiment, the temperature is set at 5 ° C. intervals. However, output data is collected at three set points, for example, −15, 20, and 55 ° C., and as required. Output data of another intermediate point may be calculated by interpolation and stored. Further, when the detected temperature is within the temperature interval, for example, it is determined in advance that output data of a set temperature close to this temperature is read.

[0026]

As described above, according to the present invention, the position can be detected irrespective of the magnetization polarity of the guide tape, and the marker detecting magnetoresistive element is not required.
Moreover, since an inexpensive Hall element can be used as a magnetoresistive element without a sorting operation for making the temperature characteristics uniform, a position detecting device having good temperature characteristics can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the first invention.

FIG. 2 is a block diagram showing an embodiment of the second invention.

FIG. 3 is a diagram showing a configuration example of a guide tape used in the embodiment of FIG. 2;

FIG. 4 is a block diagram showing an embodiment of the third invention.

FIG. 5 is a block diagram illustrating an example of a conventional position detection device.

6 is an arrangement diagram of the magnetic detection device in FIG.

FIG. 7 is a layout diagram of a conventional guide tape and marker tape.

[Explanation of symbols]

H _{1 to} H _n Hall elements MPX _{1 to} MPX _n First switch MPX ′ _{1 to} MPX ′ _n Second switch TH ₁ Temperature detector A ₁ , A ₂ amplifier SPC Single chip computer AD ₁ , AD ₂ A / D converter CPU central processing unit ROM memory CH ₁ to CH _n output terminals

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F063 AA02 BA11 BA30 CA40 CB01 DA01 DB04 DD06 DD08 GA52 GA64 GA65 GA73 JA09 LA09 LA11 LA19 LA29 5H301 AA02 AA09 CC03 CC06 EE06 EE13 EE28 FF04 FF15 FF27 GG25 GG29 HH01

Claims (3)

[Claims] 1. A position detecting device for detecting a position in a width direction of a magnetized guideway for guiding an autonomous self-driving unmanned vehicle to travel, wherein the position detection device is spaced apart from each other in the width direction of the guideway. A plurality of Hall elements, first and second driving means for sequentially driving the Hall elements, and control means for alternately operating the first and second driving means to extract a position detection signal; A position detecting device for a self-contained traveling unmanned vehicle, comprising: 2. The control device according to claim 1, wherein the guideway includes a traveling portion and a marker portion between the traveling portion and a marker portion that is magnetized to have a different polarity from that of the traveling portion. 2. The position detecting device for an autonomous traveling unmanned vehicle according to claim 1, wherein the marker signal is extracted by judging the passage of the marker portion from a position detection signal obtained at the time of operation of the vehicle. 3. At least one temperature detecting element, and each set temperature of the Hall element in a magnetic field applied to the magnetic detecting element as a reference value is detected by the temperature detecting element. Data writing means for sequentially storing each output data of the Hall element in a predetermined storage means; reading means for reading output data corresponding to the temperature detected by the temperature detection element stored when used; 3. An independent traveling type unmanned vehicle according to claim 1, further comprising: output means for comparing output data with an output of said hall element and outputting a detection signal according to a result of the comparison. Detection device.