JP3538503B2 - Guidance control device for mobile vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field detecting means provided on a ground side with a guide wire to which a current is supplied, and on a moving vehicle side detecting a strength of a magnetic field formed by the current.
A storage unit for storing detection information of the magnetic field detection unit; a distance detection unit for detecting a traveling distance of the moving vehicle; and a magnetic field in each of a plurality of parallel traveling paths along a longitudinal direction of the guide line. A steering control means for controlling a steering operation means for controlling a traveling direction of the vehicle body to guide the moving vehicle along each of the traveling paths based on information detected by the detection means; Current traveling detecting the strength of the magnetic field for the current traveling route to execute the guidance control along the traveling traveling route when traveling along one of the plurality of traveling routes. A magnetic field detecting unit for a route, and a magnetic field for a next traveling route that is detected by the magnetic field detecting unit for the current traveling route when the mobile vehicle travels along an adjacent next traveling route. Next running time to detect strength And a storage unit for sequentially storing the detection value of the magnetic field detection unit for the next traveling route in association with the traveling distance information detected by the distance detection unit. When the steering control means causes the mobile vehicle to travel along the next adjacent traveling route, the storage information stored in the storage means and the magnetic field detection for the current traveling route The present invention relates to a mobile vehicle guidance control device configured to control a steering operation means to guide a mobile vehicle along each of the traveling paths based on detection information of a section.

[0002]

2. Description of the Related Art A guidance control device for a mobile vehicle having the above-described structure has a characteristic that the strength of a magnetic field formed by a current supplied to a guide wire is determined according to a distance from the guide wire. The mobile vehicle can be guided to travel on each of a plurality of parallel traveling routes along the guide line based on the detection information of the strength of the vehicle. Moreover, when traveling along one traveling route, the strength of the magnetic field in the next neighboring traveling route is detected in advance and stored in association with the traveling distance information, and the stored information is used as a control target. By controlling the direction, the strength of the magnetic field is measured and set as the control target. It is possible to perform guided traveling, and it is not necessary to store all the reference information of the magnetic field strength in a plurality of traveling paths, so that the capacity of the storage means can be reduced and the configuration can be simplified.

Conventionally, in such a mobile vehicle guidance control device, a detection value detected by the magnetic field detection unit for the next traveling route is stored in a storage unit as it is, and the stored information is stored in a corresponding traveling route. It was used as a control target.

[0004]

However, the above conventional configuration has the following disadvantages and has room for improvement. That is, when the strength of the magnetic field is detected by the magnetic field detection unit for the next traveling route, for example, when the moving vehicle is temporarily inclined in the front-rear direction or the lateral width direction during traveling, or when an external magnetic field source is detected. In the case where a magnetic field is generated due to, for example, an appropriate value due to such disturbance,
That is, a magnetic field strength different from the value corresponding to the relative distance between the travel route and the guide line may be detected. In the prior art as described above, since the detection value detected by the magnetic field detection unit for the next traveling route is stored as it is, the information having the error caused by the disturbance as described above is directly manipulated. It is used as the control target of the direction control. Such an error due to disturbance often occurs locally in a short time, and the rate of change of the detected value with respect to the traveling distance is large. As a result, when the guidance control is performed in the next traveling route based on such stored information, a sudden steering operation is performed in the disturbance occurrence portion, and a response delay occurs until the vehicle returns to the appropriate guidance state. In some cases, a large error may occur. Then, each time the moving vehicle travels on each traveling route, such an error is accumulated, and the error gradually becomes large, so that there is a possibility that an appropriate guided traveling along the traveling route cannot be performed.

The present invention has been made in view of such a point, and an object of the present invention is to perform optimal guided traveling as much as possible on each of a plurality of scheduled traveling routes even if the traveling is affected by disturbance or the like. It is an object of the present invention to provide a guidance control device for a mobile vehicle that can perform the control.

[0006]

According to the first aspect of the present invention, when the vehicle travels along one of the plurality of traveling routes, the distance is detected by the distance detecting means in the storage means. The detection value of the magnetic field detection unit for the next traveling route stored corresponding to the traveling distance information is subjected to smoothing processing by the smoothing processing unit so as to reduce the change amount with respect to the unit traveling distance. The steering control means uses the processing information processed by the smoothing processing means as a control target when the mobile vehicle travels along the next travel route, and sets the control target and the current travel The steering operation means for controlling the traveling direction of the vehicle body is controlled so that the deviation from the detection value of the route magnetic field detection unit is reduced.

Therefore, for example, the detection value of the magnetic field detection unit for the next traveling route stored in the storage means locally changes due to a change in the attitude of the vehicle body or disturbance due to an external magnetic field source. Even in this case, the smoothing processing means
Since the detected value is smoothed so that the amount of change with respect to the unit traveling distance becomes small, when the vehicle is guided along the next traveling route, the vehicle body traveling direction controlled by the steering operation means sharply changes. The steering operation is performed as smoothly as possible, and it is possible to suppress the error from increasing further in the next traveling route.

As a result, the amount of information to be stored is small as compared with the configuration in which the control targets corresponding to all the traveling paths are stored, and the configuration can be simplified accordingly, and the strength of the magnetic field actually measured in each traveling route is reduced. Based on the above, while utilizing the conventional advantage of being able to perform guided traveling in a state corresponding to the previous traveling route as much as possible, errors in the magnetic field detection information generated due to the above-described disturbance gradually accumulate. It is possible to suppress the increase and to perform the optimal guided traveling as much as possible on each traveling route.

According to a second aspect of the present invention, the smoothing processing means includes a control unit configured to determine, from among the detection values stored in the storage means, a detection value of the magnetic field detection unit for the current traveling route and a control target. The smoothing process is executed based on only the appropriate detection value of the magnetic field detection unit for the next traveling route when the deviation is equal to or less than the set amount.

Therefore, when the deviation between the detected value of the magnetic field detection unit for the current traveling route and the control target is equal to or less than the set amount, that is, proper guidance traveling in which the moving vehicle travels along the traveling route is performed. Only the appropriate detection value is used, and the deviation exceeds the set amount, that is, proper guidance traveling is not performed due to various factors, and a detection error is detected in the magnetic field detection unit for the next traveling route. Since the smoothing process is performed in a state in which the detection value in a state where there is a risk of occurrence of the magnetic field is excluded, the error in the magnetic field detection information can be minimized, and it is possible to perform more appropriate guided traveling. Become.

[0011] According to a third aspect of the present invention, in addition to the second aspect, the smoothing processing means may be configured to control the next travel route when the deviation exceeds the set amount. The smoothing process is performed by using processing information equalized for each of the appropriate detection values on the upper traveling side and the lower traveling side of the detected values instead of the detection values of the magnetic field detection unit for use. It is configured to

Therefore, by removing the error caused by the locally generated disturbance and using the processing information in which the appropriate detected values before and after the removed area are equalized, the entire area in the next traveling route can be obtained. The detection information of the strength of the magnetic field corresponding to the traveling distance information is stored in an appropriate state with a small error due to disturbance, and an appropriate guided traveling can be performed on each traveling route.

According to a fourth aspect of the present invention, the smoothing process is a spline interpolation process. The detection value of the magnetic field detection unit for the next traveling route is approximated by a smooth curve by spline interpolation processing, the amount of change with respect to the unit traveling distance is reduced, and errors due to locally changing disturbance are smoothed. In addition, the maximum value of the error can be suppressed as small as possible.

According to a fifth aspect of the present invention, the traveling vehicle is provided with a route end detecting unit for detecting that the traveling vehicle is at the end of the traveling route, and the steering control means is controlled by the route end detecting unit. It is configured to cause the storage means to start a storage operation when detecting that the moving vehicle is located at the start end of the travel route.

Accordingly, when the route end detecting section detects that the moving vehicle is located at the start end of the traveling route, the storing operation is automatically started in the storage means.
Compared to the case where the start of the storage operation is artificially instructed, the detection value of the magnetic field detection unit for the next travel route is reliably stored from an appropriate position, and the guided travel based on the stored information is performed. It can be performed properly.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a guidance control device for a mobile vehicle according to the present invention will be described. The guidance control device for mobile vehicles
As shown in FIG. 1, in a rectangular field 1 as an example of a guidance area, a work vehicle V as an example of a moving vehicle is placed on each of a plurality of traveling paths k parallel to each other along the longitudinal direction of the field 1. It is configured so that the vehicle can be guided and guided in an unmanned state.

On each side (ridge) in the outer peripheral portion of the field 1,
Each of the guide wires 2 having substantially the same length as the length of the ridge is installed along the longitudinal direction of the ridge, and each of the guide wires 2 is provided with an AC current having a predetermined frequency by a current supply source as a current supply means. Is supplied. That is, alternating currents of the frequency fa (Hz) and the frequency fc (Hz) are supplied to the respective guide lines 2 a and 2 c installed along the ridges on both sides along the long direction of the field 1 by the respective current supply sources 3. The frequency fb (Hz) and the frequency fd are supplied by each current supply source 3 to each of the guide wires 2b and 2d which are supplied and installed on the ridges on both sides along the short direction.
(Hz) alternating current is supplied. The frequency is
The frequency is set to several hundred Hz to several tens KHz.

As shown in FIG. 2, each of the guide wires 2 is configured such that the current flows through the ground through a plurality of piles 4 made of a conductive material that is driven into the ground. , Even if the leads are installed over long distances,
It is configured so that installation can be easily performed only by driving the stake 4 on both sides in the longitudinal direction. In the ground, the driving depth of the pile 4 is set so that current flows through the lower clay layer GD2 having a relatively low electric resistance, instead of the ground layer GD1 having a relatively high electric resistance.

When a current flows through the guide wire installed as described above, a magnetic field is formed by the current. The theoretical value of the magnetic field strength with respect to the distance from the guide wire can be obtained by calculation. The strength of the magnetic field is inversely proportional to the square of the distance from the guide wire. Therefore, if the supplied current value is constant, as shown in FIG. 3, the change characteristic of the strength of the magnetic field with respect to the distance from the induction wire is determined, and the magnetic field at a certain point in the field 1 is determined. Has a substantially constant magnitude.

The work vehicle V is provided with a rotary tilling device 6 as a working device at the rear of the four-wheeled traveling vehicle body 5 so that the ground work (tiling work) of the field 1 can be performed while traveling. Has become. An engine is mounted on the traveling vehicle body 5, and the power of the engine is transmitted to each wheel via a transmission equipped with a forward / reverse switching mechanism 7 capable of turning on and off the power transmission so that the vehicle travels. At the same time, the power of the engine is transmitted to the rotary tilling device 6. The left and right front wheels are provided so as to be steerable by an electric motor 9 as a steering operation means for controlling the traveling direction of the vehicle body.

The work vehicle V has a running distance sensor 10 as a distance detecting means, for example, a rotary encoder for detecting the running distance of the vehicle body by detecting the number of revolutions of the axle, and the direction of the vehicle body. An azimuth sensor 11 as azimuth detecting means, a control device 12 using a microcomputer for controlling operations of the forward / reverse switching mechanism 7, the steering electric motor 9, and the like are provided.

At the front of the traveling vehicle body 5, the strength of a magnetic field formed by an alternating current supplied to each of the guide lines is detected as information on the position (separation distance) of the work vehicle with respect to each of the guide lines. Three magnetic field sensors are provided in a state of being juxtaposed along the vehicle body width direction. Of these, the side magnetic field sensors 13R and 13L located on the left and right sides are the ridges on both sides along the long direction of the field 1. Guide lines 2a, 2 installed along
c is detected as the strength of the magnetic field formed by the alternating current having the frequency fa and the frequency fc. Is configured to detect the position information from each of the guide wires 2b and 2d installed along the ridges on both sides along the short direction as the strength of the magnetic field formed by the alternating current of the frequency fb and the frequency fd. I have.

The control device 12 moves the work vehicle V along each traveling route k on each of the plurality of traveling routes k on the basis of information detected by the side magnetic field sensors 13R and 13L as the magnetic field detecting means GK. Is performed, and based on information detected by the central magnetic field sensor 14 as a route end detection unit, each travel route k is controlled.
When the vehicle reaches the terminal end or the start end of the vehicle, and when it detects that the terminal end is reached, it performs a turning control for causing the work vehicle V to turn around and guide the vehicle V to enter an adjacent next traveling route. It is provided with control means 100.

That is, as shown in FIG. 4, the outputs of the side magnetic field sensors 13R and 13L and the central magnetic field sensor 14 are respectively processed by a signal processing unit 15 and then given to the control unit 12, and these magnetic field Based on the detection information, the steering electric motor 9 is guided so as to be guided along each traveling route k.
At the end of the traveling route k, the magnetic field detection information and the direction sensor 11 and the traveling distance sensor 1
Based on the detection information of 0, the steering electric motor 9, the forward / reverse switching mechanism 7, and the like are controlled so as to make a turning run.

As shown in FIG. 5, the central magnetic field sensor 14 includes a detection coil 16a in which an induced electromotive force is generated by an alternating magnetic field formed by an alternating current flowing through the induction wire;
An amplifier 16b that amplifies the output of the detection coil 16a to a predetermined level, and a frequency filter that passes only the output of the detection coil 16a that corresponds to the frequencies fb and fd of the current flowing through each of the induction wires 2b and 2d. It comprises a band-pass filter BPF, a DC conversion circuit DC for converting its output into a DC signal, and the like.

The side magnetic field sensors 13R and 13L respectively include a vertical detecting coil 17 for detecting a magnetic field component of an alternating magnetic field formed by an alternating current flowing through the induction wires 2a and 2c along the vehicle vertical direction, and a vehicle width direction. , Detecting the magnetic field component along the horizontal direction, and amplifiers 19 and 2 for amplifying the output of each of these detection coils to a predetermined level.
0, a band-pass filter BPF as a frequency filter that passes only the output corresponding to the frequencies fa and fc of the currents flowing through the induction wires 2a and 2c among the outputs of the detection coils 17 and 18, and converts the output to a DC signal DC conversion circuit DC, and calculation units 21 and 22 for calculating the strengths of the respective magnetic fields based on the vertical and horizontal components corresponding to the respective frequencies fa and fc. I have. As shown in FIG. 12, the calculation units 21 and 22 calculate the strength of the composite magnetic field r by performing calculations based on the vehicle vertical component p and the width component q based on the triangle theorem. It is configured.

With this configuration, for example, FIG.
As shown in FIG. 2 (a), even when the work vehicle V is running and one of the wheels enters the recess and the vehicle body is inclined at an angle θ from the horizontal posture, the vehicle is supplied to the guide line. The magnetic field formed by the currents
As shown in FIG.
By calculating the resultant magnetic field by calculation, an accurate magnetic field strength, that is, a separation distance from the guide wire can be accurately detected.

As described above, each side magnetic field sensor 13R, 1
3L, detection information corresponding to each of the frequency fa and frequency fc is output, and the central magnetic field sensor 14 outputs detection information corresponding to each of the frequency fb and frequency fd. However, in the signal processing unit 15, the detection information of the higher detection level, that is, the detection information of the one closer to the guide line to which the work vehicle V corresponds is selectively output. The signal processing unit 15
As shown in the figure, each of the magnetic field sensors 13R, 13L, 14
Is output to the control device 12, and the control device 12 determines the output of the higher detection level from among the outputs of different frequencies of the magnetic field sensors 13R, 13L, and 14 and selects the output. Analog switches AS _1,
AS _{2 and} AS ₃ are configured to supply a selection signal.

The controller 12 includes a central magnetic field sensor 14
Based on the detection information, the distance from one of the guide lines 2b and 2d installed on the ridge along the short direction with the higher detection level is calculated, and the distance becomes the set value. Then, it is configured to determine that the work vehicle V has reached the end position of each traveling route k. The guide lines 2b and 2d installed on the ridges along the short direction are shown in FIG.
As shown in FIG. 3, the both end portions are installed in a state of being bent substantially in an L shape toward the inside of the field 1. With this configuration, at the point where the separation distance of the guide lines 2b and 2d from the intermediate portion t is the set distance, the strength of the magnetic field becomes substantially the same over the entire length of the guide lines 2b and 2d. It is set as the end position of k. This end position is
The point is located on the inward side of the field 1 by a set distance from the length L of the end bent portion. By the way, according to the applicant's experiment,
If the length H of the bent end portion is, for example, 3 m, the end portion is located at a distance of 5 m from the guide wire.

As described above, the reason why the end position of the traveling route k is set inward of the end of the field 1 is that, as shown in FIG.
In the magnetic field strength distribution at a point where the separation distance is the same, the relationship between the magnetic field strength and the separation distance is not linear near the end of the guide wire, and there is a possibility that the guidance control based on the magnetic field strength may not be performed well. Because there is.

Further, as shown in FIG.
As a frequency filter, which is an example of a current suppressing unit that suppresses a current flowing through another induction line from flowing through the ground, a band-pass filter 23 that allows only the frequency of a current supplied to the induction line to pass is provided. Have been. The band-pass filter 23 is configured by a resonance circuit in which a coil 23a and a capacitor 23b are connected in series, and is configured such that its resonance frequency corresponds to the frequency of the current. Therefore, even if a current of a different frequency flows through the ground from another induction wire, the inflow current is suppressed from flowing through the induction wire, and the possibility that each magnetic field sensor detects erroneous information is minimized. I have.

The detection of each of the side magnetic field sensors 13R and 13L is performed.
Each analog switch AS corresponding to output information₁, AS_ThreeOut of
The amplification gain for amplifying the force is
Change and adjust to multiple stages (four stages) based on switching information
It is configured to In other words, each of the amplification gains
Output signals of four different amplifiers 24, 25, 26, 27
For inputting one of the two to the control device 12.
Switch AS_Four, AS _FiveIs selected by the control device 12
It is configured to dictate the content. Supplied to the guide wire
The strength of the magnetic field formed by the current
Changes greatly with changes in the separation distance.
If the amplification gain is kept constant,
It is difficult to detect with appropriate resolution and detection accuracy is low
To the control device 12
The input level is, for example, as shown in FIG.
The appropriate magnetic field strength when the separation distance changes by a unit distance
So that the change in height is identifiable, in other words
Amplification gain so that it is in the appropriate output range with high resolution
Is automatically adjusted.

The side magnetic field sensors 13R and 13L are
One of the side magnetic field sensors is disposed at a set interval in the vehicle width direction, and when one of the side magnetic field sensors travels along one of the plurality of traveling paths k, the traveling vehicle V Magnetic field detection unit G for the current traveling route for detecting the strength of the magnetic field in order to execute the guidance control along the traveling route k inside
K ₁ , and the other side magnetic field sensor is detected by the magnetic field detector GK ₁ for the current traveling route when the work vehicle travels along the next adjacent traveling route k. Field detection unit GK for the next traveling route for detecting the intensity of the magnetic field
It is configured to function as ₂ . In other words, the other side magnetic field sensor sequentially detects the magnetic field of the next traveling route k while traveling on the current traveling route k, and this detection information is the distance information detected by the traveling distance sensor 10. In such a state, the information is sequentially stored in a memory M as a storage means.

The steering control means 100 detects the magnetic field detection information stored in the memory M and the end of the travel path k detected by the travel distance sensor 10 in the next travel path k in which the magnetic field detection information is stored. based on the travel distance information from the position, obtains a target value of the strength of the magnetic field at each point on the travel route k, and its target value, and functions as a magnetic field detector GK ₁ for the current travel route side It is configured to execute guided traveling control for driving and controlling the traveling electric motor 9 based on a deviation from the detection value of the magnetic field sensor.

The steering control means 100 stores the information in the memory M.
Based on the stored magnetic field detection information,
Field detection for the current traveling route when guided by
Depart GK₁Set the output gain target value for
Prior to the guided traveling on the traveling route k, the output gain is adjusted.
It is configured to automatically adjust to a target value. Specifically
Is that the maximum value of the magnetic field strength stored in the memory M is
If the gain adjustment setting upper limit value is exceeded, the current gain
An amplifier having a gain one stage lower than the maximum value is selected.
Is below the lower limit for gain adjustment, the current
Select an amplifier with a gain one step higher than the gain
And the analog switch AS_Four, AS_FiveSelect signal for
Command. Each analog switch A
S_Four, AS _FiveGain is always adjusted to the same value.
ing. Upper limit and lower limit for gain adjustment
The value guarantees the linearity of the output change as an analog value.
Are set as upper and lower limits.

[0036] Further, the steering control unit 100 includes a detection value of the lateral magnetic field sensor which serves as a magnetic field detector GK ₁ for the current travel route, a steering operation amount deviation is multiplied by a control constant between the target value That is, the target operation amount of the electric motor 9 is determined. Then, based on the magnetic field detecting unit GK ₁ and the magnetic field strength of the detection information detected by the magnetic field detector GK ₂ for the next travel path for current travel route, the time of traveling the next travel path, the operation It is configured to correct the control constant so that the amount falls within an appropriate range.

Next, the control operation of the steering control means 100 will be described. When the work vehicle V is guided to travel in the field 1, the first travel route k is set prior to the automatic guidance control.
In, the work vehicle V is caused to travel by manual operation in a state along the appropriate traveling route k. At that time, the traveling route k
As the vehicle starts traveling from the start end position of the vehicle, the side magnetic field sensor (the right sensor 1 in the case of FIG.
In the state where the detection information of 3R) and the detection information of the traveling distance sensor 10 are associated with each other, the information is sequentially written and stored in the memory M. Also, of the plurality of data sampled at every set time as the vehicle travels on the first travel route, the left and right side magnetic field sensors 13R, 13R near the center of the travel route are provided.
The average value of the difference values of a plurality (n) of sampling data α ₁ ... Α _n , β ₁ ... Β _n of the respective detected values of 13L is determined, and the average value is set in advance based on experiments or the like. based on the constant γ is obtained in advance a control constant for the steering control in the travel route as a reference control constants G _1. Specifically, the calculation is performed based on the following [Equation 1].

[0038]

(Equation 1)

Then, the work vehicle is moved to the starting end of the next traveling route k.
After the vehicle is moved to, the guided driving control is started.
Prior to that, as shown in FIG.
Magnetic field detector GK₁Side magnetic field sensor that functions as
In the case of 1, the left sensor 13L) is initialized (scan).
Together with step 1) before it is applied on that route
The control constant is set (step 2). Of this control constant
To explain the setting, the starting point of the current travel route
Of the left and right side magnetic field sensors 13R and 13L
The difference value Zn of the output value is obtained, and the difference value Zn
Difference value Z in traveling route₁And the reference control constant G
₁Based on the following [Equation 2]
Control constant Gn is calculated. Note that each of the difference values Z
n, Z₁Is set sampling for each driving route
The average value of multiple detection values sampled every time
Is calculated.

[0040]

Gn = (Z ₁ / Zn) · G ₁

The setting of the control constant Gn is executed for each traveling route at the beginning of the traveling route. In other words, using the left and right side magnetic field sensors 13R and 13L, the degree of change in the strength of the magnetic field along the vehicle body width direction in the path on which the work vehicle travels is determined, and control for steering control in each travel path is performed. It is configured to determine a constant.

Then, while the work vehicle V is traveling at the traveling speed for work, based on the magnetic field detection information stored in the memory M and the detection information of the traveling distance sensor 10, the current position on the traveling route k seeking a target value of the strength of the magnetic field, the steering operation amount deviation is multiplied by a control constant between the detection value and the target value of the lateral magnetic field sensor 13L functioning as the magnetic field detecting unit GK ₁ for the current travel route The steering electric motor 9 is drive-controlled so as to obtain the steering operation amount (step 3). When the guided travel control is performed, the side magnetic field sensor follows the travel path side that functions as the magnetic field detecting unit GK ₂ for the next travel path (right side of the sensor 13R in the case of FIG. 1)
Are sequentially written and stored in the memory M in a state in which the detection information of the traveling distance sensor 10 corresponds to the detection information of the traveling distance sensor 10 (step 4).

When it is detected based on the detection information of the central magnetic field sensor 14 that the terminal of the traveling route k has been reached,
The number n of traveling routes is counted up (steps 5 and 6),
If the count value has not reached the set number of routes ns of in the field 1 (step 7), the memory M to write the stored magnetic field strength maximum value Xm of, beyond the gain adjustment setting an upper limit value S _GM The analog switch AS so that an amplifier having a gain one stage lower than the current gain is selected.
₄ , a selection signal is commanded to AS ₅ to change the output gain to a lower side (steps 8 and 9). The maximum value Xm
Is smaller than the setting lower limit value _SGL for gain adjustment, a selection signal is issued to the analog switches AS ₄ and AS ₅ so that an amplifier having a gain one stage higher than the current gain is selected. , The output gain is changed to the higher side (steps 10 and 11). When the output gain is changed in this way, the control constant is also appropriately corrected according to the change amount (steps 12 and 13).

In this manner, the drive control of the electric motor 9 is always performed with an appropriate control constant in accordance with the detected value of the magnetic field strength and the change situation of the output gain, so that hunting of control and detection error can be prevented. The generation is suppressed as much as possible.

Next, the side magnetic field sensor which serves as a magnetic field detector GK ₁ for the current travel route is switched to that of the opposite side (the right side of the sensor 13R) (step 14). This is because their positional relationship is reversed by a change in the direction of the vehicle body.

Next, turning control for turning the vehicle in a turning direction so as to be positioned at the start end of the next traveling route k is executed (step 15). As shown in FIG. 13 (a), after the vehicle travels straight ahead while maintaining the steering operation in the neutral state for a set distance from the end position of the traveling route k, the direction sensor 11 is reset, and the direction of the vehicle body is 180 degrees. The vehicle travels at the maximum turning angle until it is detected that the vehicle has reversed, and then travels straight until it is detected that the vehicle has reached the start end of the next traveling route k based on the detection information of the central magnetic field sensor 14. (Step 16).

At the starting point of the next traveling route,
As shown in FIG. 13B, based on the detection information of the side magnetic field sensor functioning as the magnetic field detection unit for the current traveling route k and the storage information stored in the memory M, the next traveling route is determined. It is necessary to move the vehicle forward while turning so as to be in line with it, and to perform width adjustment. At this time, the magnetic field detection information for the next traveling route is in a bent state. An appropriate state is corrected based on the detection information of the path and the detection information of the degree of change in the magnetic field as described above. After that, the guidance traveling control is executed in a state of being along the traveling route.

After it is detected based on the detection information of the central magnetic field sensor 14 that the head of the next travel route k has been reached, the detection value of the magnetic field detector GK ₁ for the current travel route and the target When the set time elapses after the deviation from the value (stored information) falls within the set range and the value is stabilized, the above-described setting of the control constant is executed. That is, the left and right side portions field sensor 13R in the current travel route, the difference value Zn of the detected value of each of 13L, based on the difference value Z ₁ and the reference control constants G ₁ in the first traveling path, above [equation 2 ], The control constant Gn in this traveling route
Is calculated. The difference value Zn in the current traveling route
Is calculated based on the detection information on the start end side.

Thereafter, the above-described guided traveling control is executed. At this time, if the gain has been changed in steps 9 and 11, the amount of change in the detection information stored in the memory M is also changed. Is multiplied by the gain corresponding to the target value. Then, steps 2 to 15 are repeated, and the work vehicle V is sequentially guided along each traveling path k, and when the number of the set paths reaches ns, the control ends (step 7).

In the current traveling route k, the strength of the magnetic field stored when traveling on the preceding traveling route k and the current traveling route k
Is controlled to be the same as the detected magnetic field at
Since the installation interval of each of the side magnetic field sensors 13R and 13L is set to be narrower than the working width of the rotary tilling device 6 with respect to the ground, the working area of the rotary tilling device 6 wraps on each traveling path k. That is, no unworked area is generated. Also, each side magnetic field sensor 13
The installation intervals of R and 13L can be changed and adjusted freely.

Then, the control device 12 receives the detected value of the magnetic field detecting unit GK ₂ for the next traveling route stored in the memory M in correspondence with the traveling distance information.
In order to reduce the amount of change per unit mileage,
As an example of the smoothing process, a smoothing processing unit 101 that executes a spline interpolation process that is a well-known technique in the information processing technology field is provided in a control program format.
The spline interpolation process is an interpolation process for approximating data with a smooth curve, and is a processing method based on a function approximation using a spline, which is a function defined by a piecewise polynomial, as an interpolation formula.

[0052] By executing such a spline interpolation, for example, as shown in FIG. 14 (b), the change characteristic of the detected value of the magnetic field detecting portion GK ₂ for the next travel route for travel distance (specifically , A series of measurement points detected at predetermined intervals, which are indicated by lines in FIG. 14 for convenience). In FIG. 14, detection is performed due to disturbance such as a tilt of the vehicle body or a magnetic field from an external magnetic field source. Even when the value changes locally, the interpolation processing is performed so as to form a smooth curve as shown in FIG.

[0053] Moreover, the smoothing processing unit 101, among the detected values stored in the memory M, the control target for the detection value of the magnetic field detecting portion GK ₁ for the current travel route, guided travel control deviation based only on proper detection value of the magnetic field detector GK ₂ for the next travel path when that is the less than the set amount,
Is configured to perform a spline interpolation, the deviation in place of the detection value of the magnetic field detector GK ₂ for the next travel route when it exceeds the set amount, the traveling upstream side and the running of their detection value The spline interpolation processing is executed using processing information equalized for each of the appropriate detection values on the lower side.

[0054] For example, as shown in FIG. 15 (b), the detection value of the magnetic field detector GK ₂ for the next travel path includes a disturbance such as deviated from the proper value, the state is continued In such a case, when the spline interpolation processing of such data is performed, as shown in FIG. 15C, the data in the flat region in the disturbance occurrence portion causes the curve portion to bend greatly and include a large error. I will. Therefore,
Since such a disturbance is considered to be a state in which the vehicle body is displaced from the proper traveling state, FIG.
As shown in (a), when the vehicle body is traveling properly,
That is, the detection value of the magnetic field detecting portion GK ₁ for the current travel route, the magnetic field detecting unit GK for the next traveling path when the deviation between the control target for the guided travel control becomes a small value less than the set amount
With using only ₂ proper detection value, instead of the detection value of the magnetic field detector GK ₂ for the next traveling path when the deviation becomes a larger value beyond the set amount, the travel of their detection value By executing the spline interpolation process using the equalized processing information for each of the appropriate detection values on the upper side and the lower side on the traveling side, as shown in FIG. The control target for the next traveling route can be set in a state where it is reduced as much as possible. Note that the equalization is to supplement each of the appropriate detection values on the upper traveling side and the lower traveling side with data that changes substantially linearly.

The steering control means 100 is configured to execute the above-described guided traveling control with the processing information processed by the smoothing processing means 101 as a control target.

[0056] Other Embodiments (1) In the above embodiment, instead of the detection value of the magnetic field detector GK ₂ for the next traveling path when the deviation during the guided travel exceeds the set amount, the equalization The smoothing process is performed using the processed information. However, without using such equalized values, for example, in a region where there is no detected value, the vehicle is guided to travel straight. Travel control may be performed.

[0057] (2) In the above embodiment, using only proper detection value of the magnetic field detecting portion GK ₂ for the next travel route when the deviation during the guided travel is less than a set amount, to perform the smoothing process However, instead of such a configuration, the smoothing process may be performed using all the detected values.

(3) In the above embodiment, the case where the spline interpolation processing is used as the smoothing processing has been exemplified. However, the change amount of the detection value of the magnetic field detection unit for the next traveling route with respect to the unit traveling distance becomes small. What is necessary is just to perform the smoothing processing as described above, and is not limited to the spline interpolation processing.

(4) In the above-described embodiment, the end of the traveling route is detected by the central magnetic field sensor as the route end detecting unit. A laser beam may be irradiated in the lateral direction, and the end of the route may be detected by a sensor that detects the laser beam. The present invention may be implemented in various configurations such as a configuration instructing the side.

(5) In the above embodiment, the case where the guide lines are provided on both the left and right sides of the guidance target area has been exemplified. However, the guide lines may be provided on only one side. May be sequentially guided from a traveling route closer to the guide line to a route farther away, or may be sequentially guided from a traveling route farther from the guide line to a route closer to the guide line.

(6) In the above embodiment, the vehicle is a four-wheeled vehicle and the left and right front wheels are provided so as to be able to swing freely. However, all four wheels are provided so as to be able to swing freely, and the front and rear wheels are mutually movable. A configuration in which the vehicle turns with a small turning radius that swings in different directions or a configuration in which the front and rear wheels swing in the same direction and the moving vehicle moves in parallel in an oblique direction may be adopted. Further, a configuration including a pair of left and right crawler traveling devices and a steering operation configuration for applying braking to one side may be employed.

(7) In the above embodiment, the rotary tilling device is provided as the moving vehicle. However, the moving vehicle may be provided with a seedling transplanting device, a chemical spraying device, or the like. It may be a mobile vehicle such as a transport vehicle that does not include the vehicle.

[Brief description of the drawings]

FIG. 1 is a plan view showing a guidance state.

FIG. 2 is a side view showing an installation state of a guide wire.

FIG. 3 is a diagram showing a magnetic field intensity distribution.

FIG. 4 is a control block diagram.

FIG. 5 is a configuration diagram of a magnetic field detection unit.

FIG. 6 is a configuration diagram of a signal processing unit.

FIG. 7 is a plan view showing an installation state of a guide wire.

FIG. 8 is an electric circuit diagram of an induction wire.

FIG. 9 is a diagram showing output characteristics when the output gain is switched.

FIG. 10 is a flowchart of a control operation.

FIG. 11 is a plan view of a moving vehicle.

FIG. 12 is a diagram showing a magnetic field detection state.

FIG. 13 is a diagram showing a turning control state.

FIG. 14 is a diagram showing a state of a smoothing process.

FIG. 15 is a diagram showing a state of smoothing processing when equalization is performed;

[Explanation of symbols]

2 the magnetic field of the induction line 9 steering operating means 10 distance detecting means 14 path end portion detecting section 100 steering control unit 101 smoothing processing means GK magnetic field detector GK ₁ for the magnetic field detector GK ₂ following the travel path for the current travel route Detector M Storage means V Moving vehicle

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Yokoyama 64 Ishizukita-cho, Sakai-shi, Osaka Kubota Sakai Works Co., Ltd. (56) References JP-A-5-123006 (JP, A) JP-A-Hei-6 285196 (JP, A) JP-A-6-335547 (JP, A) JP-A-2-287708 (JP, A) JP-A-8-286748 (JP, A) JP-A-9-212234 (JP, A) JP-A-9-294413 (JP, A) JP-A-9-297616 (JP, A) JP-A-10-56816 (JP, A) JP-A-10-56817 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G05D 1/02

Claims (5)

(57) [Claims] 1. A guide wire to which an electric current is supplied is installed on the ground side, and a magnetic field detecting means for detecting the strength of a magnetic field formed by the electric current is provided on a moving vehicle side; and detection information of the magnetic field detecting means. A distance detecting means for detecting a traveling distance of the moving vehicle; and a plurality of traveling paths along a longitudinal direction of the guide line and parallel to each other, based on information detected by the magnetic field detecting means. A steering control means for controlling a steering operation means for controlling a traveling direction of a vehicle body so as to guide a moving vehicle along each of the traveling paths. The magnetic field detecting means comprises a plurality of traveling paths. When traveling along one of the following, a magnetic field detecting unit for the current traveling route for detecting the strength of the magnetic field for the current traveling route to execute the guidance control along the traveling route during the traveling; The next run next to A magnetic field detection for the next traveling route that detects the strength of the magnetic field for the next traveling route that is detected by the magnetic field detection unit for the current traveling route when the mobile vehicle travels along the traveling route. And the storage unit is configured to sequentially store a detection value of the magnetic field detection unit for the next traveling route in association with traveling distance information detected by the distance detection unit, The steering control means, when the mobile vehicle travels along the adjacent next travel route, storage information stored in the storage means, and detection information of the magnetic field detection unit for the current travel route. A guidance control device for a mobile vehicle configured to control a steering operation means to guide the mobile vehicle along each of the traveling paths based on the travel distance information. Is stored in correspondence with The detection value of the magnetic field detector for the next travel path,
Smoothing processing means is provided for performing smoothing processing so that the amount of change with respect to the unit traveling distance is reduced, and the steering control means uses processing information processed by the smoothing processing means as a control target, A guidance control device for a mobile vehicle configured to control the steering operation means such that a deviation between the control target and a detection value of the magnetic field detection unit for the current traveling route is reduced. 2. The smoothing processing means according to claim 1, wherein, among the detection values stored in the storage means, a deviation between the detection value of the magnetic field detection unit for the current traveling route and the control target is equal to or less than a set amount. The guidance control device for a mobile vehicle according to claim 1, wherein the smoothing process is executed based only on the appropriate detection value of the magnetic field detection unit for the next traveling route when the following condition is satisfied. 3. The smoothing processing means according to claim 1, wherein, when the deviation exceeds the set amount, the detected values of the magnetic field detection unit for the next traveling route are replaced by the upper traveling side and the traveling value of the detected values. 3. The guidance control device for a mobile vehicle according to claim 2, wherein the smoothing process is performed using process information equalized for each of the appropriate detection values on the lower side. 4. The guidance control device for a mobile vehicle according to claim 1, wherein the smoothing process is a spline interpolation process. 5. A traveling vehicle according to claim 5, wherein said traveling vehicle is provided with a route end detecting unit for detecting that the traveling vehicle is at an end of said traveling route. The guidance control of a mobile vehicle according to any one of claims 1 to 4, wherein the storage unit is configured to start a storage operation when detecting that the storage unit is located at a start end of a route. apparatus.