JP6991058B2 - Automatic steering system - Google Patents

Description

The present invention relates to an automatic steering system for automatically traveling a work vehicle along a set turning circle.

The agricultural work vehicle according to Patent Document 1 is provided with a GPS receiving device that receives radio waves from GPS satellites, and automatically travels so as to follow a target route based on the calculated position of the own vehicle. In straight-ahead driving, if the vehicle body deviates from the linear target path, that is, if the control reference point installed on the vehicle body center line deviates from the target path, the position deviation (positional deviation) and the directional deviation Steering control is performed based on (direction deviation). In turning, the center of the front wheel on the front side of the vehicle body is set as the control reference position, and the control reference position with respect to the tangential vector of the vehicle body passing through the intersection of the straight line connecting the center of the turning path and the control reference position and the turning path. The position deviation and the orientation deviation are calculated. Steering control is performed based on the calculated position deviation and azimuth deviation.

Japanese Unexamined Patent Publication No. 2002-358122

In the steering control according to Patent Document 1, in order to obtain the position deviation (position deviation amount) and the orientation deviation (direction deviation amount), the intersection of the straight line connecting the turning center of the turning path and the control reference position and the turning path. It is necessary to calculate the tangent vector of the vehicle body passing through the above, but the calculation of the tangent vector takes a long time because the calculation load is high. In addition, since a work vehicle uses a smaller turning radius than a passenger car, the tangent vector changes rapidly during turning, and it is necessary to calculate the tangent vector with a high calculation load in a short time. be. In order to do this, a high cost arithmetic function is required.
In view of such circumstances, there is a demand for an automatic steering system capable of accurate steering control by calculating the amount of positional deviation and the amount of directional deviation at high speed by a simple calculation method in turning traveling.

The automatic steering system according to the present invention for automatically traveling a work vehicle equipped with a storage tank for storing harvested grains along a turning circle set as a travel target route calculates the position of a reference point in the work vehicle. Reference point calculation unit and
A reference straight line calculation that calculates a straight line passing through the center of the turning circle and the reference point, which is set to connect the pre-turning path and the post-turning path having different extension directions with an arc having a predetermined radius. The position deviation amount calculation unit that calculates the distance from the intersection of the reference straight line and the turning circle to the reference point as the position deviation amount, and the vehicle body orientation that indicates the direction of the vehicle body of the work vehicle. The calculation unit, the azimuth deviation amount calculation unit that calculates the intersection angle between the line passing through the reference point and perpendicular to the reference straight line and the vehicle body orientation as the azimuth deviation amount, and the positional deviation amount and the azimuth deviation amount are small. A steering control unit that outputs a steering amount is provided, and the radius of the turning circle is adjusted by the amount of grains stored in the storage tank before the work vehicle travels on the turning circle. Such steering can be performed forward and backward.
It should be noted that the swirling circle here is not limited to a strict circle, but also includes an approximate circle, and further includes a swirling circle whose radius changes in a minute time and whose center changes. ..

In this configuration, a linear formula of a reference straight line connecting the center of the turning circle that is the set travel target and the reference point of the work vehicle is calculated, and by using this reference straight line, the linear formula of the tangent line is not obtained. In addition, the amount of misalignment and the amount of misalignment can be calculated by a simple calculation. That is, the amount of misalignment is the distance (length) between the intersection of the reference straight line and the turning circle and the reference point. The directional deviation amount is an angle formed by a straight line that passes through the reference point and is perpendicular to the reference straight line and a straight line that indicates the vehicle body orientation calculated by the vehicle body orientation calculation unit. The obtained positional deviation amount and directional deviation amount are input amounts for obtaining the steering amount in the steering control unit.

As described above, in the present invention, since the amount of misalignment and the amount of misalignment can be obtained by a simple calculation, the amount of misalignment and the amount of misorientation can be calculated at high speed by a simple calculation method in turning. , It is possible to provide an automatic steering system capable of accurate steering control.

The length between the intersection of the reference straight line and the turning circle, which is the amount of misalignment, and the reference point is the difference between the length between the center of the turning circle and the reference point and the radius of the turning circle. Therefore, in one of the preferred embodiments of the present invention, the misalignment amount calculation unit subtracts the radius of the swivel circle from the length between the center of the swirl circle and the reference point in the reference straight line. By doing so, the distance is calculated.

In one of the preferred embodiments of the present invention, the steering control unit uses a PID control method or a PI control method to control the steering amount by using the current steering amount, the position deviation amount, and the orientation deviation amount as input parameters. Calculate and output. With this configuration, control hunting is suppressed and the turning running of the work vehicle becomes smooth. As a result, it is possible to prevent the field from being damaged by turning.

In one of the preferred embodiments of the present invention, as the turning circle, a turning circle for sharp turning and a turning circle for slow turning are prepared so as to be selectable. In this configuration, it is possible to select a turning run using a more appropriate turning circle according to the field state and the running state.

In one of the preferred embodiments of the present invention, the radius of the turning circle set in the next turning run is adjusted based on the turning running error in the previous turning run. In this configuration, for example, if the work vehicle bulges outward from the turning circular arc that is the target route due to a field condition that deteriorates the turning performance of the work vehicle, the radius will be larger for the next turn. By selecting a large turning circle, smooth running along the turning circle arc becomes possible.

It is a side view of a combine as an example of a work vehicle which adopted an automatic steering system. It is a figure which shows the outline of the automatic traveling of a combine. It is a figure which shows the traveling route in automatic driving. It is a figure which shows the example of the turning travel path using the reverse movement. It is a figure which shows the example of the turning travel path using the reverse movement. It is a functional block diagram which shows the structure of the control system of a combine. It is explanatory drawing explaining the basic principle used when calculating the misalignment amount and the azimuth misalignment amount. It is a schematic diagram which shows another embodiment in a turning control. It is a schematic diagram which shows another embodiment in a turning control. It is a schematic diagram which shows another embodiment in a turning control. It is a schematic diagram which shows another embodiment in a turning control.

Next, an ordinary combine harvester will be described as an example of a working machine capable of automatically traveling by adopting the automatic steering system of the present invention. In the present specification, unless otherwise specified, "front" (direction of arrow F shown in FIG. 1) means front in the vehicle body front-rear direction (traveling direction), and "rear" (arrow B shown in FIG. 1). Direction) means the rear in the vehicle body front-rear direction (traveling direction). Further, the left-right direction or the lateral direction means a vehicle body crossing direction (vehicle body width direction) orthogonal to the vehicle body front-rear direction. "Up" (direction of arrow U shown in FIG. 1) and "down" (direction of arrow D shown in FIG. 1) are positional relationships in the vertical direction (vertical direction) of the vehicle body, and are relationships in height above the ground. show.

As shown in FIG. 1, this combine includes a traveling vehicle body 10, a crawler-type traveling device 11, a driving unit 12, a threshing device 13, a grain tank 14, a harvesting section H, a transport device 16, a grain discharging device 18, and a self. It is equipped with a vehicle position detection module 80.

The traveling device 11 is provided in the lower part of the traveling vehicle body 10 (hereinafter, simply referred to as the vehicle body 10). The combine is configured to be self-propelled by the traveling device 11. The traveling device 11 is a steering traveling device composed of a pair of left and right crawler mechanisms (traveling units). The crawler speed of the left crawler mechanism (left traveling unit) and the crawler speed of the right crawler mechanism (right traveling unit) can be adjusted independently, and by adjusting this speed difference, the orientation of the vehicle body 10 in the traveling direction can be adjusted. Be changed. The driving unit 12, the threshing device 13, and the grain tank 14 are provided on the upper side of the traveling device 11 and form the upper part of the vehicle body 10. The driver unit 12 can be boarded by a driver who drives the combine harvester and a monitor who monitors the work of the combine harvester. Usually, the driver and the observer are also used. When the driver and the observer are different persons, the observer may monitor the work of the combine from outside the combine.

The grain discharge device 18 is connected to the rear lower portion of the grain tank 14. Further, the own vehicle position detection module 80 is attached to the front upper portion of the driving unit 12.

The harvesting section H is provided at the front of the combine. The transport device 16 is connected to the rear side of the harvesting section H. Further, the harvesting unit H has a cutting mechanism 15 and a reel 17. The cutting mechanism 15 cuts the planted culm in the field. Further, the reel 17 is driven to rotate and scrapes the planted culm to be harvested. With this configuration, the harvesting unit H harvests the grain (a kind of agricultural product) in the field. Then, the combine can be run by the traveling device 11 while harvesting the grains in the field by the harvesting unit H.

The cut grain culm cut by the cutting mechanism 15 is conveyed to the threshing device 13 by the conveying device 16. In the threshing device 13, the harvested grain culm is threshed. The grains obtained by the threshing treatment are stored in the grain tank 14. The grains stored in the grain tank 14 are discharged to the outside of the machine by the grain discharging device 18.

A communication terminal 2 is arranged in the driving unit 12. In the present embodiment, the communication terminal 2 is fixed to the driving unit 12. However, the present invention is not limited to this, and the communication terminal 2 may be configured to be detachable from the driving unit 12. It may also be taken out of the combine.

As shown in FIG. 2, this combine automatically travels along a travel route set in the field. For this purpose, the position of the own vehicle is required. The own vehicle position detection module 80 includes a satellite navigation module 81 and an inertial navigation module 82. The satellite navigation module 81 receives a GNSS (global navigation satellite system) signal (including a GPS signal) from the artificial satellite GS and outputs positioning data for calculating the position of the own vehicle. The inertial navigation module 82 incorporates a gyro acceleration sensor and a magnetic orientation sensor, and outputs a position vector indicating an instantaneous traveling direction. The inertial navigation module 82 is used to complement the vehicle position calculation by the satellite navigation module 81. The inertial navigation module 82 may be arranged at a different location from the satellite navigation module 81.

The procedure for harvesting in the field with this combine is as described below.

First, the driver / observer manually operates the combine harvester and, as shown in FIG. 2, performs a harvesting run so as to orbit along the boundary line of the field in the outer peripheral portion of the field. As a result, the area that has become the already cut land (already worked area) is set as the outer peripheral area SA. Then, the area left as the uncut land (unworked land) inside the outer peripheral area SA is set as the work target area CA. FIG. 2 shows an example of the outer peripheral area SA and the work target area CA.

Further, at this time, in order to secure a certain width of the outer peripheral region SA, the driver causes the combine to travel 3 to 4 laps. In this traveling, the width of the outer peripheral region SA is expanded by the working width of the combine every time the combine makes one round. After the first 3 to 4 laps, the width of the outer peripheral region SA becomes about 3 to 4 times the working width of the combine. This orbital running may be performed by automatic running based on the out-of-field shape data given in advance.

The outer peripheral region SA is used as a space for the combine to change direction when performing a harvesting run in the work target region CA. Further, the outer peripheral region SA is also used as a space for movement such as when moving to a grain discharge place or when moving to a refueling place after the harvesting run is finished.

The carrier CV shown in FIG. 2 can collect and transport the grains discharged from the combine. At the time of grain discharge, the combine moves to the vicinity of the carrier CV and then discharges the grains to the carrier CV by the grain discharge device 18.

When the outer peripheral area SA and the work target area CA are set, the traveling route in the work target area CA is calculated as shown in FIG. The calculated travel route is sequentially set based on the work travel pattern, and the combine automatically travels along the set travel route. As a turning pattern for turning, this combine repeats a U-turn pattern that changes direction along a U-shaped turning path as shown in FIG. 3 and forward / backward movement as shown in FIG. It has an α-turning pattern that changes direction and a switchback turning pattern that changes direction in a region narrower than the U-turning pattern with reverse travel as shown in FIG. In the α turning pattern of FIG. 4, a 90 ° turning turning path is shown. In this turning turn, the route reaches the transition destination travel route L2 from the transition source travel route L1 via the forward travel route ML1, the reverse travel route ML2, and the forward travel route ML3. The switchback turning pattern of FIG. 5 shows a 180 ° turn-back turning running used in a route transition in a straight reciprocating running. Similarly, in this turning turn travel, the route reaches the transition destination travel route L2 from the transition source travel route L1 via the forward travel route ML4, the reverse travel route ML5, and the forward travel route ML6. Such turning traveling including reverse movement is also performed when the grain tank 14 is full and the combine that has left the traveling path of the work target area CA aligns with the carrier CV.

FIG. 6 shows a combine control system using the automatic steering system according to the present invention. The control system of the combine is from a control unit 5 consisting of a large number of electronic control units called ECUs and various input / output devices that perform signal communication (data communication) with the control unit 5 through a wiring network such as an in-vehicle LAN. It is configured.

The notification device 62 is a device for notifying the driver and the like of a working driving state and various warnings, and is a buzzer, a lamp, a speaker, a display, and the like. The communication unit 66 is used for the control system of this combine to exchange data with the communication terminal 2 or with a management computer installed at a remote location. The communication terminal 2 also includes a tablet computer operated by a monitor standing in the field, a driver / monitor who is on board the combine, a computer installed at home or a management office, and the like. The control unit 5 is a core element of this control system and is shown as an aggregate of a plurality of ECUs. The signal from the vehicle position detection module 80 is input to the control unit 5 through the vehicle-mounted LAN.

The control unit 5 includes an output processing unit 503 and an input processing unit 502 as input / output interfaces. The output processing unit 503 is connected to various operating devices 70 via the device driver 65. The operating equipment 70 includes a traveling equipment group 71, which is a traveling-related device, and a working equipment group 72, which is a work-related device. The traveling device group 71 includes, for example, a steering device 710, an engine device, a speed change device, a braking device, and the like. The work equipment group 72 includes a harvesting unit H, a threshing device 13, a transport device 16, a power control device in the grain discharge device 18, and the like.

A traveling state sensor group 63, a working state sensor group 64, a traveling operation unit 90, and the like are connected to the input processing unit 502. The traveling state sensor group 63 includes an engine rotation speed sensor, an overheat detection sensor, a brake pedal position detection sensor, a shift position detection sensor, a steering position detection sensor, and the like. The work state sensor group 64 includes a sensor for detecting the driving state of the harvesting work device (harvesting unit H, threshing device 13, transport device 16, grain discharging device 18), a sensor for detecting the state of the grain and the grain, and the like. It is included.

The traveling operation unit 90 is a general term for operating tools that are manually operated by the driver and whose operation signals are input to the control unit 5. The traveling operation unit 90 includes a main speed change operation tool 91, a steering operation tool 92, a mode operation tool 93, an automatic start operation tool 94, and the like. In the manual driving mode, the crawler speed of the left crawler mechanism and the crawler speed of the right crawler mechanism are adjusted by swinging the steering operation tool 92 from the neutral position to the left and right, and the direction of the vehicle body 10 is changed. .. The mode operating tool 93 has a function of giving a command to the control unit 5 for switching between an automatic driving mode in which automatic driving is performed and a manual driving mode in which manual driving is performed. The automatic start operation tool 94 has a function of giving a final automatic start command to the control unit 5 for starting automatic running. The transition from the automatic driving mode to the manual driving mode may be automatically performed by software regardless of the operation by the mode operating tool 93. For example, when a situation occurs in which automatic driving is impossible, the control unit 5 forcibly executes a transition from the automatic driving mode to the manual driving mode.

The control unit 5 includes a notification unit 501, a travel control unit 51, a work control unit 52, a travel mode management unit 53, a travel route setting unit 54, a vehicle position calculation unit 55, a vehicle body orientation calculation unit 56, and a misalignment amount calculation unit. 57, an orientation deviation amount calculation unit 58, and a reference straight line calculation unit 59 are provided. The notification unit 501 generates notification data based on a command or the like from each functional unit of the control unit 5, and supplies the notification data to the notification device 62. The own vehicle position calculation unit 55 calculates the own vehicle position, which is the map coordinates (or field coordinates) of the preset reference point of the vehicle body 10, based on the positioning data sequentially sent from the own vehicle position detection module 80. do. That is, it functions as a reference point calculation unit for calculating the position of the reference point of the vehicle body 10. This reference point includes a vehicle body reference point and a turning reference point, which will be described later. The vehicle body orientation calculation unit 56 obtains a traveling locus in a minute time from the own vehicle position sequentially calculated by the own vehicle position calculation unit 55, and determines the vehicle body orientation indicating the direction of the vehicle body 10 in the traveling direction. Further, the vehicle body direction calculation unit 56 can also determine the vehicle body direction based on the direction data included in the output data from the inertial navigation module 82.

The travel control unit 51 has an engine control function, a steering control function, a vehicle speed control function, and the like, and gives a control signal to the travel equipment group 71. The work control unit 52 gives a control signal to the work equipment group 72 in order to control the movement of the harvesting work equipment (harvesting unit H, threshing device 13, transport device 16, grain discharging device 18, etc.).

The steering control unit 510 included in the traveling control unit 51 determines the steering amount based on the position deviation amount calculated by the position deviation amount calculation unit 57 and the direction deviation amount calculated by the direction deviation amount calculation unit 58. It is calculated and output to the steering device 710. That is, the steering control unit 510 determines the amount of misalignment and the amount of directional deviation between the target travel path set by the travel route setting unit 54 and the vehicle position calculated by the vehicle position calculation unit 55. Steering control is performed so that it becomes smaller. In this embodiment, a PID control method or a PI control method is adopted for the steering control unit 510. Of course, other control methods may be adopted. This combine can be driven by both automatic driving in which harvesting work is performed by automatic driving and manual driving in which harvesting work is performed by manual driving. Therefore, the travel control unit 51 further includes a manual travel control unit 511 and an automatic travel control unit 512. When performing automatic driving, an automatic driving mode is set, and for manual driving, a manual driving mode is set. As described above, the switching of the traveling mode is managed by the traveling mode management unit 53.

When the automatic driving mode is set, the automatic driving control unit 512, in cooperation with the steering control unit 510, generates a control signal for changing the vehicle speed including automatic steering and stopping, and controls the traveling equipment group 71. .. At that time, the control signal regarding the vehicle speed change is generated based on the vehicle speed value set in advance.

The travel route setting unit 54 sequentially selects a travel route including a managed turning route and sets it as a travel target route. The swivel path is essentially an arc of a swivel circle. The arc-shaped turning path is defined by the center of the turning circle and the radius of the turning circle. Assuming that the vehicle body 10 travels on the turning path accurately, the center of the turning circle is the turning center of the vehicle body 10. The travel route managed by the travel route setting unit 54 can be generated by the travel route setting unit 54 by the route calculation algorithm, but the one generated by the communication terminal 2 or the management computer at a remote location is downloaded. It is also possible to use.

When the manual driving mode is selected, the manual driving control unit 511 generates a control signal based on the operation by the driver and controls the traveling equipment group 71 to realize the manual driving. The travel route calculated by the travel route setting unit 54 can be used for the purpose of guidance for the combine to travel along the travel route even in manual operation.

The misalignment amount calculation unit 57 calculates the misalignment, which is the distance between the travel route set by the travel route setting unit 54 and the vehicle position calculated by the vehicle position calculation unit 55. The directional deviation amount calculation unit 58 calculates the angle difference between the extension direction of the travel path set by the travel route setting unit 54 and the vehicle body orientation calculated by the vehicle body orientation calculation unit 56 as the directional deviation. In this embodiment, the own vehicle position calculated by the own vehicle position calculation unit 55 is set as a turning reference point which is a point on which the vehicle rides on the turning path defined by the turning circle in an ideal turning running without deviation. .. Of course, even in ideal driving without deviation in a straight traveling path, this turning reference point rides on the straight traveling path, so that the turning reference point can be used as a vehicle body reference point in the straight traveling path. In that case, the turning reference point and the vehicle body reference point are the same.

The reference straight line calculation unit 59 calculates the reference straight line. The reference straight line is used for the calculation of the misalignment amount by the misalignment amount calculation unit 57 and the calculation of the misalignment calculation by the misalignment amount calculation unit 58 in the turning run. Next, the relationship between the reference straight line, the amount of misalignment, and the amount of misorientation will be described with reference to FIG. 7.

FIG. 7 shows the relationship between the turning circle and the vehicle body 10 set when turning from the pre-turning running path, which is the running path before turning, to the post-turning running path, which is the running path of the turning destination. In this example, since the traveling path before turning and the traveling path after turning are orthogonal to each other, the turning path is a 90 ° arc of a turning circle. The reference numerals used in the description of FIG. 7 are defined as follows. C represents a swirling circle. P is the center of the turning circle C. The coordinate value of the center P of the turning circle is (X, Y) and is managed by the traveling route setting unit 54. R is the radius of the turning circle C. The VP is a turning reference point (vehicle body reference point) of the vehicle body 10, and is represented by coordinate values (x, y). The coordinate values (x, y) of the turning reference point VP are calculated by the own vehicle position calculation unit 55. CL is a vehicle body center line which is a center line extending in the front-rear direction of the vehicle body 10. d is the distance between the center P of the turning circle and the turning reference point VP. BL is a straight line connecting two points, the center P of the turning circle and the turning reference point VP, and this straight line is the "reference straight line". PL is a straight line that passes through the turning reference point VP and is perpendicular to the reference straight line BL, and is hereinafter referred to as “direction reference line”.

FIG. 7 shows a state in which the vehicle body 10 is in the middle of turning, and the vehicle body 10 is displaced to the outside of the turning circle C and the vehicle body direction (vehicle body center line CL) is displaced to the right side with respect to the directional reference line PL. ing. The reference straight line calculation unit 59 obtains a linear formula connecting two points, the center P of the turning circle and the turning reference point VP, and calculates the reference straight line BL. The misalignment amount calculation unit 57 calculates the distance between two points d between the center P of the turning circle and the turning reference point VP, and calculates the misalignment amount δ by subtracting R from the distance d between the two points. In this subtraction, the positive and negative signs are taken into consideration, and if the subtraction value is negative, the vehicle body 10 is displaced inside the turning circle C, and if the subtraction value is positive, the vehicle body 10 turns. This means that the position is shifted to the outside of the circle C. The directional deviation amount calculation unit 58 calculates the angle (intersection angle) formed by the vehicle body center line CL and the directional reference line PL as the directional deviation amount θ. If the directional deviation amount θ is a positive value, the vehicle body 10 is displaced to the right in the traveling direction, and if the directional deviation amount θ is a negative value, the vehicle body 10 is displaced to the left in the traveling direction. It will be. In this way, the displacement amount δ and the azimuth deviation amount θ are calculated and given to the steering control unit 510 in minute traveling units, so that the steering amount based on the PID or PI control is output.

An example of the procedure for calculating the steering amount in turning is shown below.
(1) The coordinate values (x, y) of the turning reference point VP, which is the position of the vehicle body 10 of the vehicle body 10, are acquired from the vehicle position calculation unit 55.
(2) Obtain the linear equation of the reference straight line BL.
(3) The distance d between two points, which is the length between the center P of the turning circle C and the turning reference point VP, is obtained.
(4) The turning circle radius R is subtracted from the distance d between the two points, and the value is taken as the misalignment amount δ.
(5) The linear equation of the vehicle body center line CL is obtained based on the vehicle body orientation from the vehicle body orientation calculation unit 56.
(6) The directional reference line PL perpendicular to the reference straight line BL is calculated based on the linear equation of the reference straight line BL, and the angle (intersection angle) formed by the vehicle body center line CL and the directional reference line PL is set as the directional deviation amount θ. calculate.
(7) Subtract 90 ° from the angle α, and use that value as the azimuth deviation amount θ.
(8) The steering amount is calculated from the misalignment amount δ and the azimuth deviation amount θ.

If, instead of (3) and (4), the intersection of the reference straight line BL and the turning circle C can be easily obtained, the distance between the obtained intersection and the reference point VP should be calculated. The amount of misalignment δ can be obtained. If a straight line that passes through the reference point and is perpendicular to the reference straight line can be easily obtained, change to (6) and directly set the angle (intersection angle) between the vehicle body center line CL and the reference straight line BL. The value obtained by subtracting 90 ° from the angle may be used as the orientation deviation amount θ.

Next, the measures to be taken when a turning running error occurs due to automatic steering using a turning circle are listed.
(A) FIG. 8 shows a situation in which a misalignment amount δ occurs at the end of turning in a turning running on a set turning circle C (the radius of the turning circle C is R). As the cause of such a turning deviation, there are considered to be multiple causes such as "the direction of the vehicle body 10 is shifted at the start of turning" or "the actual turning radius is increased due to slipping in the field or the like". Therefore, it is difficult to take decisive measures. In order to solve this problem, an optimized turning circle Co capable of appropriately turning is calculated from the actual positions and directions of the vehicle body 10 at the start and end of turning. As shown in FIG. 8, the straight line K1 passing through the turning reference point VP of the vehicle body 10 at the start of turning and perpendicular to the vehicle body center line CL and the vehicle body center line CL passing through the turning reference point VP of the vehicle body 10 at the end of turning. Find the intersection with the straight line K2 perpendicular to, and the circle passing through the turning reference point VP of the vehicle body 10 at the start of turning and the turning reference point VP of the vehicle body 10 at the end of turning is the optimized turning circle. Yes, it has a radius Rc. In the subsequent turning running, by setting this optimized turning circle Co, turning running with less turning deviation can be expected.

(B) FIG. 9 shows that when a turning running error occurs in the turning running in the set turning circle C, the turning running error is taken into consideration in the next turning running to realize a turning running with less turning deviation. It shows the strategy to try. Here, a function: F (δ) for deriving the shift amount ΔL of the turning start point required to eliminate the misalignment amount δ is used with the misalignment amount δ generated in the first turning run as an input parameter. .. Such a function F (δ) can be created through simulations and experiments. With the shift amount ΔL derived by the function F (δ), it is expected that the turning shift in the next turning run will be reduced by shifting the turning start point Ps of the next turning path to the modified turning start point Pc. ..

(C) FIG. 10 shows a turning deviation improving measure similar to the turning deviation improving measure shown in FIG. Here, a function: G (δ) for deriving the adjustment amount ΔR of the radius of the turning circle required to eliminate the misalignment amount δ is used with the misalignment amount δ generated in the first turning run as an input parameter. Be done. Such a function G (δ) can also be created through simulations and experiments. In the next turning run, the optimized turning circle Co having the radius Rc adjusted by the adjustment amount ΔR derived by the function G (δ) is used instead of the turning circle C. At that time, the center P of the turning circle also moves to the new center P'. By using this optimized turning circle Co, it is expected that the turning deviation will be reduced.

(D) FIG. 11 shows the directional deviation amount θs of the vehicle body 10 at the start of turning and the directional deviation amount of the vehicle body 10 at the end of turning when a turning running error occurs in the turning running on the set turning circle C. This describes a measure for adjusting the turning circle set in the next turning running by using θe and, to realize turning running with less turning deviation. Therefore, here, the directional deviation amount θs at the start of turning and the directional deviation amount θe at the start of turning are used as input parameters, and the adjustment amount ΔR of the radius of the turning circle C required to eliminate the turning deviation is derived. Function: J (θs, θe) is used. Such a function J (θs, θe) can also be created through simulations and experiments. In the next turning run, the turning deviation is reduced by using the optimized turning circle Co having the radius Rc adjusted by the adjustment amount ΔR derived by the function J (θs, θe) instead of the turning circle C. There is expected.

(E) It is empirically known that the turning radius based on the turning trajectory of the actual combine varies depending on the amount of grains stored in the grain tank 14. As described above, the turning running error caused by the stored grain amount V can be improved by setting a turning circle whose radius is adjusted by the stored grain amount V. For this purpose, a function: H (V) for deriving the adjustment amount ΔR of the radius of the swirling circle is used with the stored grain amount V as an input parameter. At that time, it is preferable to set the adjustment amount ΔR when V = 0 to 0 and gradually increase the adjustment amount up to the full amount.

In the countermeasures (A) to (E) described above, it was assumed that the turning circle in which the turning deviation occurred and the turning circle to be turned next have the same radius, but if the turning circles have different radii. On the other hand, when the above-mentioned measures are applied, the problem due to the difference in radius of the swirling circle can be solved by using the correction coefficient table for correcting the difference in radius prepared in advance.

[Another embodiment]
(1) In the above-described embodiment, the turning circle used for the turning path is included in the traveling path generated by the traveling route creation algorithm for the field or artificially generated, and is included in the traveling path during traveling. , The travel route setting unit 54 sequentially sets the target travel route. At that time, an example in which the radius of the turning circle is automatically changed based on the occurrence of turning deviation or the like has also been described. In addition to this, a configuration may be adopted in which the radius of the turning circle is artificially changed. For example, there are multiple turning modes such as "gentle mode" in which a turning circle with a large radius (turning circle for slow turning) is set and "high speed mode" in which a turning circle with a small radius (turning circle for sharp turning) is selected. An artificial operation tool that can be selected may be provided. When the "gentle mode" is selected, turning that does not disturb the field as much as possible is realized, and when the "high speed mode" is selected, the turning running time is shortened and the working time is shortened. The actual turning radius of the vehicle body 10 is determined by the difference in crawler speed between the left and right crawler mechanisms or the speed difference between the left and right drive wheels, but in the hydraulic transmission mechanism that transmits the traveling power to the crawler mechanism and the drive wheels. It is also possible to adjust the turning radius by adjusting the hydraulic pressure.

(2) In the above-described embodiment, the own vehicle position detection module 80 is a combination of the satellite navigation module 81 and the inertial navigation module 82, but only the satellite navigation module 81 may be used. Further, a method of calculating the position of the own vehicle and the direction of the vehicle body based on the image taken by the camera may be adopted.

(3) Each functional unit shown in FIG. 6 is divided mainly for the purpose of explanation. In practice, each functional unit may be integrated with other functional units or may be divided into a plurality of functional units. Further, among the functional units built in the control unit 5, all of the travel mode management unit 53, the travel route setting unit 54, the position deviation amount calculation unit 57, the orientation deviation amount calculation unit 58, and the reference straight line calculation unit 59. , Or a part of it is built on a portable communication terminal 2 (tablet computer, etc.) that can be connected to the control unit 5, and adopts a configuration that exchanges data with the control unit 5 via wireless or in-vehicle LAN. May be good.

It should be noted that the configuration disclosed in the above embodiment (including another embodiment, the same shall apply hereinafter) can be applied in combination with the configuration disclosed in other embodiments as long as there is no contradiction. , The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

The present invention is applicable not only to a normal type combine but also to a self-removing type combine. It can also be applied to various harvesters such as corn harvesters, potato harvesters, carrot harvesters and sugar cane harvesters, and field work vehicles such as rice transplanters and tractors. Furthermore, it can be applied to lawn mowers and construction machines.

5: Control unit 10: Vehicle body (running vehicle body)
11: Travel device 51: Travel control unit 510: Steering control unit 511: Manual travel control unit 512: Automatic travel control unit 52: Work control unit 53: Travel mode management unit 54: Travel route setting unit 55: Own vehicle position calculation unit 56: Body direction calculation unit 57: Positional deviation amount calculation unit 58: Directional deviation amount calculation unit 59: Reference straight line calculation unit 80: Own vehicle position detection module 81: Satellite navigation module 82: Inertial navigation module BL: Reference straight line C: Turning Circle CL: Body center line PL: Direction reference line R: Turning circle radius VP: Turning reference point (reference point)
δ: Amount of misalignment θ: Amount of misalignment

Claims (7)

It is an automatic steering system that automatically drives a work vehicle equipped with a storage tank for storing harvested grains along a turning circle set as a travel target route .
A reference point calculation unit that calculates the position of the reference point in the work vehicle,
A reference straight line calculation that calculates a straight line passing through the center of the turning circle and the reference point, which is set to connect the pre-turning path and the post-turning path having different extension directions with an arc having a predetermined radius. Department and
A misalignment amount calculation unit that calculates the distance from the intersection of the reference straight line and the swivel circle to the reference point as the misalignment amount.
A vehicle body orientation calculation unit that calculates the vehicle body orientation indicating the orientation of the vehicle body of the work platform, and
An orientation deviation amount calculation unit that calculates the intersection angle between the line passing through the reference point and perpendicular to the reference straight line and the vehicle body orientation as the orientation deviation amount.
A steering control unit that outputs a steering amount that reduces the misalignment amount and the azimuth deviation amount is provided.
An automatic steering system in which the radius of the turning circle is adjusted by the amount of grains stored in the storage tank before the working vehicle travels on the turning circle. The automatic method according to claim 1, wherein the misalignment amount calculation unit calculates the distance by subtracting the radius of the turning circle from the length between the center of the turning circle and the reference point in the reference straight line. Steering system. The steering control unit according to claim 1 or 2, wherein the steering control unit calculates and outputs the steering amount by a PID control method or a PI control method using the current steering amount, the position deviation amount, and the orientation deviation amount as input parameters. Automatic steering system. The automatic steering system according to any one of claims 1 to 3, wherein a sharp turning circle and a slow turning circle are selectively prepared as the turning circle. The automatic steering system according to any one of claims 1 to 4, wherein the radius of the turning circle set in the next turning run is adjusted based on the turning running error in the previous turning run. The adjustment of the radius of the swirling circle uses a function: H (V) preset so as to derive the adjustment amount of the radius of the swirling circle with the stored grain amount: V as an input variable. The automatic steering system according to any one of 5 to 5. The automatic steering system according to claim 6, wherein the function: H (V) is an increasing function that gradually increases with an increase in the amount of stored grains: V.

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