JP7206099B2 - Control device for self-driving work vehicle - Google Patents

Description

The present invention relates to a control device for a work vehicle that automatically travels along a target travel route.

Patent Literature 1 discloses an agricultural work vehicle that automatically travels along a preset target travel route. In this agricultural work vehicle, the steering mechanism is controlled so that the vehicle position calculated using GPS is directed to a target point set on the target travel route. At this time, the distance from the vehicle body front side portion to the target point is set so as to decrease as the length (lateral deviation) of the vertical line drawn from the vehicle body front side portion to the target travel route increases.

Patent Document 2 discloses a working vehicle in which a target steering value is calculated from a lateral deviation with respect to a target travel route and an azimuth deviation with respect to the target travel route, and a steering drive signal is output based on the target steering value. Specifically, a target steering value is calculated from the first steering value and the second steering value. A first steering value is calculated based on the lateral deviation. The second steering value is calculated based on a value obtained by further adjusting the calculated value derived based on the heading deviation by a weighting factor. This weighting factor is a factor whose value decreases as the lateral deviation increases.

JP-A-2002-182741 JP 2016-155491 A

In the work vehicle according to Patent Document 1, when the vehicle body deviates significantly in the lateral direction from the target travel route, the positional deviation is eliminated by a large steering angle, and when the vehicle body deviates slightly in the lateral direction from the target travel route. , the positional deviation is eliminated at a small steering angle. By using a large steering angle, misalignment is eliminated quickly, but the problem arises that the work site is roughed up by the traveling equipment (wheels and crawlers). This problem is particularly serious when the working area is a farm field.

In the vehicle according to Patent Document 2, when the lateral deviation is large, the heading deviation is ignored to some extent and the target steering value is output with an emphasis on eliminating the lateral deviation. Therefore, when the lateral deviation is large, this work vehicle also uses a large steering angle, and the work site is roughened by the traveling device (wheels and crawlers), which is similar to the work vehicle according to Patent Document 1. A problem arises.

In view of the above circumstances, there is a need for an improved control system for returning an autonomous vehicle that has deviated from its intended travel path.

When the traveling direction is adjusted so that the own vehicle moves toward the estimated target point on the target traveling route, the positional deviation of the work vehicle from the target traveling route is reduced. Therefore, in order to solve the above problem, a control device for a work vehicle that automatically travels along a target travel route includes a vehicle position calculation unit that calculates the vehicle position of the work vehicle, and A target point estimating unit that calculates an estimated target point on the target travel route, a corrected azimuth calculation unit that calculates a corrected azimuth that eliminates the deviation between the estimated target point and the vehicle position, and inputs the corrected azimuth. a control operation unit that outputs, as a parameter, a control amount for changing the traveling direction of the work vehicle so as to reduce the deviation; An estimated heading deviation calculating section is provided for calculating an angle formed with the traveling route as an estimated heading deviation, and the corrected heading calculation unit includes a first controller for outputting a first corrected heading using the estimated heading deviation as an input parameter. , the corrected orientation is calculated based on the first corrected orientation.

In this configuration, when performing control to cause the work vehicle to travel along the target travel route, first, an estimated target point that is estimated to become a control target point on the target travel route after a predetermined time is calculated, and the estimated target point is calculated. and the position of the vehicle is calculated and output. Steering devices such as wheels and crawlers are driven by the output control amount. When controlling the work vehicle to travel along the target travel route, the position of the work vehicle on the target travel route after a predetermined time, that is, the position of the work vehicle on the target travel route away from the current position of the vehicle in the traveling direction. position is the estimated target point. Therefore, the longer the predetermined time, the smaller the deviation of the vehicle body orientation (orientation in the longitudinal direction of the vehicle body) from the estimated target point, and the smaller the control amount for driving the steering device. By appropriately setting this predetermined time according to the work vehicle on which this control device is mounted, steering control suitable for the work vehicle is realized.

The appropriate predetermined time in the control of the present invention varies depending on the type of work vehicle, and may also vary depending on various conditions such as the state of the work vehicle running surface on the work site and the running state of the work vehicle. If the type of work vehicle, working condition, field condition, and the like are collectively referred to as the condition of the work vehicle, it is preferable that the predetermined time is changed according to the condition of the work vehicle. Of course, the predetermined time may be automatically set based on the state of the operation device set by the driver for the work vehicle.

The greater the estimated heading deviation, the greater the control amount for changing the traveling direction of the vehicle body. Therefore, in order to perform this control smoothly, it is preferable that the first controller is composed of a proportional controller.

Rather than using only the estimated heading deviation as an input parameter to calculate a corrected heading for changing the running direction of the vehicle body, the distance between the vehicle body and the target running path in the lateral direction of the target running path (lateral deviation) is also an input parameter. , the vehicle body that has deviated from the target travel route can be returned appropriately. For this reason, in one preferred embodiment of the present invention, a lateral deviation calculator for calculating a distance from the vehicle position to the target travel route in a direction orthogonal to the direction of the target travel route as a lateral deviation. wherein the corrected azimuth calculation unit includes a second controller that outputs a second corrected azimuth using the lateral deviation as an input parameter, and based on the first corrected azimuth and the second corrected azimuth, the corrected A bearing is calculated.

If a simple proportional calculation is used to obtain a corrected bearing for changing the running direction of the vehicle body based on the lateral deviation, the calculated corrected bearing may become too large if the lateral deviation is large. To avoid this problem, in one preferred embodiment of the invention, said second controller preferably consists of an integral controller.

When changing the traveling direction of the vehicle body, the behavior of the vehicle body differs depending on the vehicle speed. Large changes in direction of travel at high vehicle speeds should be avoided. Therefore, it is preferable that the estimated target point moves away from the vehicle body as the vehicle speed increases. For this reason, in one of the preferred embodiments of the present invention, a vehicle speed calculation unit for calculating the vehicle speed of the working vehicle is provided, and the target point estimation unit projects the position of the vehicle onto the target travel route. The point is set as the starting point, and the position of the point after moving along the target travel route at the vehicle speed for the predetermined time is set as the estimated target point. As a result, the higher the vehicle speed, the farther the estimated target point is from the vehicle body in the running direction. Strictly speaking, the term "projection point" refers to the point of intersection between a perpendicular line drawn from a certain point and a straight line. Instead, the points of intersection between a line that is not perpendicular to the target travel route but slightly inclined and the target travel route are included in the projection points.

When changing the traveling direction of the vehicle body, the vehicle body direction, which is the orientation of the vehicle body at that time, is also taken into consideration, so that the vehicle body that has deviated from the target traveling route can more appropriately return to the target traveling route. For this reason, in one of the preferred embodiments of the present invention, a vehicle body orientation calculation section is provided for calculating a vehicle orientation indicating the orientation of the vehicle body, and the control operation unit further uses the vehicle orientation as an input parameter.

In the description of the present invention so far, the estimated target point is calculated in consideration of the position of the work vehicle after a predetermined period of time. By multiplying the vehicle speed by a predetermined time, the moving distance of the work vehicle in the predetermined time can be obtained. A work vehicle such as a combine or a rice transplanter that travels in a field does not operate at a very high speed during work, so if the approximate vehicle speed is determined in advance, the distance traveled by the work vehicle in a predetermined time can also be calculated in advance. In other words, the target point estimating section can also calculate the estimated target point simply by adding a predetermined distance set in advance to the starting point. A control device for a work vehicle that automatically travels along a target travel route according to the present invention, which utilizes this fact, comprises a vehicle position calculation unit that calculates the vehicle position of the work vehicle, and from the vehicle position: a target point estimating unit that calculates, as an estimated target point, a position that is a predetermined distance away from a projection point onto the target travel route in the traveling direction of the work vehicle on the target travel route; and the estimated target point and the vehicle position. and a control calculation that outputs a control amount for controlling the work vehicle so as to reduce the deviation, using the corrected orientation as an input parameter. and an estimated heading deviation calculation unit for calculating an angle between the target travel route and a straight line passing through the estimated target point and the vehicle position as an estimated heading deviation, wherein the corrected heading calculation unit comprises: and a first controller for outputting a first corrected heading using the estimated heading deviation as an input parameter, wherein the corrected heading is calculated based on the first corrected heading. The control device having this configuration can also obtain substantially the same effects as those described above.

1 is a side view of an ordinary combine harvester as an example of a field work vehicle; FIG. It is explanatory drawing which shows perimeter mowing driving|running|working of a combine. FIG. 10 is an explanatory diagram showing a U-turn travel pattern in which reciprocating travel connected by U-turns is repeated; FIG. 10 is an explanatory diagram showing a running pattern for spiral running using alpha-turn running; It is a functional block diagram which shows the structure of the control system of a combine. 4 is a functional block diagram for explaining the configurations of a correction azimuth calculation unit and a control calculation unit, and data input to the correction azimuth calculation unit; FIG. FIG. 5 is an explanatory diagram schematically showing the principle of elimination of deviation in the correction azimuth calculation unit; 4 is a graph showing the relationship between steering input and steering output; FIG. 5 is a graph showing a relationship between steering input and steering output that has been refined to improve steering control characteristics; FIG.

Next, as an example of an automatically traveling work vehicle equipped with the control device according to the present invention, an ordinary combine harvester will be taken up and explained. In this specification, unless otherwise specified, "front" (the direction of arrow F shown in FIG. 1) means the front with respect to the longitudinal direction of the vehicle body (running direction), and "rear" (the direction of arrow B shown in FIG. 1). direction) means the rear with respect to the vehicle longitudinal direction (running direction). Further, the left-right direction or the lateral direction means a vehicle transverse direction (vehicle width direction) perpendicular to the vehicle longitudinal 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 10, and are relative to ground level. indicates

As shown in FIG. 1, the combine includes a vehicle body 10, a crawler-type traveling device 11, an operation unit 12, a threshing device 13, a grain tank 14 as a harvested product tank, a harvesting unit 15, a conveying device 16, and a grain discharge. A device 18 and an own vehicle position detection unit 80 are provided.

The travel device 11 is provided under the vehicle body 10 . The combine is configured to be self-propelled by a travel device 11 . The driving unit 12 , the threshing device 13 and the grain tank 14 are provided above the traveling device 11 . A driver who drives the combine harvester and a supervisor who monitors the operation of the combine harvester can board the operation unit 12 . Note that the supervisor may monitor the operation of the combine from outside the combine.

The grain discharging device 18 is connected to the rear lower portion of the grain tank 14 . Also, the vehicle position detection unit 80 is attached to the upper surface of the driving section 12 .

A harvesting section 15 is provided at the front of the combine. The conveying device 16 is provided behind the harvesting section 15 . The combine can travel by the traveling device 11 while harvesting grains in the field by the harvesting unit 15 .

The harvested culms harvested by the harvesting unit 15 are conveyed to the threshing device 13 by the conveying device 16 . In the threshing device 13, harvested grain culms are threshed. Grains obtained by the threshing process are stored in the grain tank 14 . The grains stored in the grain tank 14 are discharged out of the machine by the grain discharging device 18 as necessary (such as when the tank is full).

A general-purpose terminal 4 is arranged in the operation unit 12 . In this embodiment, the general-purpose terminal 4 is fixed to the operating section 12 . However, the present invention is not limited to this, and the general-purpose terminal 4 may be configured to be detachable from the operation unit 12, or the general-purpose terminal 4 may be taken out of the combine. .

As shown in FIG. 2, this combine automatically travels along a travel route set in a field. This requires information on the position of the vehicle. The vehicle position detection unit 80 includes a satellite positioning module 81 and an inertial measurement module 82 . A satellite positioning module 81 receives GNSS (global navigation satellite system) signals (including GPS signals), which are position information transmitted from artificial satellites GS, and outputs positioning data for calculating the position of the vehicle. The inertial measurement module 82 incorporates a gyroscopic acceleration sensor and a magnetic orientation sensor, and outputs a signal indicative of the instantaneous direction of travel. The inertial measurement module 82 is used to complement the vehicle position calculation by the satellite positioning module 81 . Inertial measurement module 82 may be located at a different location from satellite positioning module 81 .

The procedure for harvesting in a field using this combine will be described below. First, the driver/monitoring operator operates the combine harvester, and as shown in FIG. The area where the mowing and harvesting work has been completed by the perimeter mowing travel is set as the outer peripheral area SA. The internal area left inside the outer peripheral area SA is an unworked area CA, which is set as a future work target area. In this embodiment, the perimeter mowing run is performed so that the unworked area CA is square. Of course, a triangular or pentagonal unworked area CA may be employed.

The outer peripheral area SA is used as a space for the combine to change direction when traveling for harvesting in the unworked area CA, which is the work target area. In addition, the outer peripheral area SA is also used as a space for movement, such as when moving to a grain discharge location or a fuel replenishment location after temporarily finishing harvesting. Therefore, in order to secure the width of the outer peripheral area SA to some extent, the perimeter mowing travel is performed automatically or manually for 2 to 3 rounds.

The transport vehicle CV shown in FIG. 2 collects the grains discharged from the grain discharging device 18 by the combine harvester and transports them to a drying facility or the like. When the grain is discharged, the combine moves to the vicinity of the carriage CV through the outer peripheral area SA, then the grain is discharged to the carriage CV by the grain discharging device 18, and the work is interrupted through the outer peripheral area SA. Return to the work start point, which is the position where

Unworked map data indicating the shape of the unworked area CA is created based on the inner circumference shape of the outer circumference area SA, which is the already worked area. Based on this unworked map data, a linear (straight line, curved line, or curved line) route is set in the unworked area CA as a working travel route in order to automatically work in the unworked area CA. A turning travel route for transitioning from one travel route for work to the next travel route for work is set in the outer peripheral area SA. The unworked map data is updated as the work on the unworked area CA progresses.

Traveling patterns used for work travel (harvesting travel) in the unworked area CA include a reciprocating travel pattern shown in FIG. 3 and a spiral travel pattern shown in FIG. The route along which the combine travels in the reciprocating travel pattern includes a work travel route parallel to one side of a polygon representing the outline of the unworked area CA and a U-turn turning route. The route along which the combine travels in the spiral travel pattern includes a work travel route parallel to one side of the polygon representing the outline of the unworked area CA and an alpha-turn route. The alpha-turn path is composed of a straight path, a reverse turning path, and a forward turning path, and is a turning path that connects working travel paths that are adjacent in the circumferential direction.

FIG. 5 shows the control system of the combine. This control system consists of a control device 5 consisting of one or more electronic control units called ECUs, and various input/output devices that perform signal communication (data communication) with this control device 5 through a wiring network such as an in-vehicle LAN. It is configured.

A control device 5 is a core element of this control system and is shown as a collection of multiple ECUs. A signal from the vehicle position detection unit 80 is input to the control device 5 through the vehicle LAN.

The control device 5 includes a notification unit 501, an input processing unit 502, and an output processing unit 503 as input/output interfaces.

The notification unit 501 generates notification data based on commands and the like from each functional unit of the control device 5 and gives the notification data to the notification device 62 . The notification device 62 is a device for notifying the driver or the like of the work running state and various warnings, and includes a buzzer, a lamp, a speaker, a display, and the like.

The input processing unit 502 is connected with the running state sensor group 63, the work state sensor group 64, the manipulator 65, and the like. The working state sensor group 64 includes sensors that detect the amount of grain stored in the grain tank 14 . The manipulator 65 is a general term for levers, switches, buttons, and the like that are manually operated by the driver and whose operation signals are input to the control device 5 .

The output processing unit 503 is connected to various operating devices 70 via device drivers 73 . As the action equipment 70, there are a traveling equipment group 71 that is equipment related to traveling and a work equipment group 72 that is equipment related to work. The traveling device group 71 includes steering devices for steering the vehicle body 10 . This steering device is a device that changes the speed of the left and right crawlers when the crawler type travel device 11 is employed as in this embodiment. When the steered wheel type travel device 11 is employed, the steering device is a device that changes the steering angle of the steered wheels.

The control device 5 includes a vehicle position calculation unit 40, a vehicle body direction calculation unit 41, a vehicle speed calculation unit 42, a travel control unit 51, a work control unit 52, a travel mode management unit 53, a work area determination unit 54, and a travel route calculation unit. 55, a lateral deviation calculator 56, a target point estimator 57, a correction azimuth calculation unit 9A, and a control calculation unit 9B.

The vehicle position calculation unit 40 calculates the vehicle position in the form of map coordinates (or field coordinates) based on the positioning data sequentially sent from the vehicle position detection unit 80 . At this time, the position of a specific location (for example, the center of the vehicle body, the end of the harvesting section 15, etc.) that serves as a reference point of the vehicle body 10 can be set as the vehicle position.

The vehicle body orientation calculation unit 41 calculates a vehicle orientation indicating the orientation of the vehicle body 10 from a plurality of vehicle positions calculated over time by the vehicle position calculation unit 40 . The vehicle body orientation can also be calculated based on the orientation data included in the output data from the inertial measurement module 82 . A vehicle speed calculation unit 42 calculates the vehicle speed from a vehicle speed sensor or the shift state of the transmission.

The work area determination unit 54 has a travel trajectory calculation function that calculates travel trajectory data by plotting the vehicle position calculated by the vehicle position calculation unit 40 over time. It has an unworked area determination function for creating unworked map data showing the shape of the area CA.

The travel route calculation unit 55 uses a registered route calculation algorithm to determine a travel route (work travel route, U-turn travel route, alpha-turn route, etc.) serving as a target travel route for automatic travel covering the unworked area CA. ) is calculated.

The travel control unit 51 has an engine control function, a travel device control function (including steering control and vehicle speed control of the vehicle body 10 ), and the like, and provides travel control signals to the travel device group 71 . The work control unit 52 gives work control signals to the work equipment group 72 in order to control the movements of the harvesting work devices (the harvesting unit 15, the threshing device 13, the conveying device 16, the grain discharging device 18, etc.).

The travel control unit 51 includes a manual travel control unit 511 , an automatic travel control unit 512 and a target travel route setting unit 513 . When the automatic driving mode is set, the vehicle is automatically driven, and when the manual driving mode is set, the vehicle is manually driven. Such switching of driving modes is managed by the driving mode management unit 53 . The target travel route setting unit 513 sets the target travel route using the work travel route and the turning travel route calculated by the travel route calculation unit 55 when the automatic travel mode is set.

The lateral deviation calculator 56 calculates, as a lateral deviation, the distance from the vehicle position to the target travel route in the direction orthogonal to the direction of the target travel route (extension direction) of the target travel route set by the target travel route setting unit 513. do.

When the manual travel mode is selected, manual travel is realized by the manual travel control unit 511 giving a control signal to the corresponding travel device group 71 via the device driver 73 based on the operation by the driver. .

When the automatic driving mode is set, the automatic driving control unit 512 provides a control signal for changing the vehicle speed including automatic steering and stopping to the corresponding driving device group 71 via the device driver 73, thereby realizing automatic driving. do. The automatic driving control section 512 outputs a control signal for automatic steering based on the control amount output from the control arithmetic unit 9B, as described below.

Next, the flow of data during calculation in the correction azimuth calculation unit 9A and the control calculation unit 9B will be described with reference to FIGS. 6 and 7. FIG. The symbols shown in FIG. 7 are defined as follows. RP indicates a reference point of the vehicle body 10 (the center of the vehicle body, the center of the working device, etc.), and is calculated based on the vehicle position from the vehicle position calculator 40 . TL is the target travel route for automatic travel set by the target travel route setting unit 513 . RL is a virtual line passing through the reference point RP of the vehicle body 10 and parallel to the target travel route TL. DL is a vehicle azimuth line indicating the vehicle azimuth, which is the orientation of the vehicle body 10 in the longitudinal direction. In FIG. 7, the vehicle azimuth line: DL is inclined from the virtual line: RL, and the inclination angle is indicated by γ. The vehicle body 10 of the combine is away from the target travel route TL on the right side of the paper surface, and the vehicle body direction line DL of the vehicle body 10 is oriented away from the target travel route TL as the vehicle travels in the vehicle travel direction. d is the lateral deviation of the vehicle body 10 calculated by the lateral deviation calculator 56 . VP is an estimated target point calculated by the target point estimator 57 . AP is an auxiliary point, which is a projection point from the reference point RP of the vehicle body 10 at the vehicle position to the target travel route TL. AL1 is a first auxiliary line, and this first auxiliary line is a straight line passing through the estimated target point: VP and the reference point of the vehicle body 10: RP. AL2 is a second auxiliary line extending radially from the reference point RP at an angle to the first auxiliary line AL1 by a correction angle (indicated by α) corresponding to a second correction azimuth to be described later. A straight line.

The target point estimator 57 calculates an estimated target point: VP, which is a position on the target travel route: TL, corresponding to the position (future vehicle position) after the vehicle body 10 has traveled from the current time. This estimated target point: VP can be calculated, for example, by the following method.
(1) Auxiliary point: AP is the starting point, and the position after moving the target travel route: TL for a predetermined time is assumed to be the estimated target point: VP. When the moving speed at that time is set as the current vehicle speed, the vehicle speed calculated by the vehicle speed calculation unit 42 is used. The predetermined time may be set in advance, or may be selected automatically or manually (by the driver or administrator) depending on the state of the harvested crops or the state of the field. In the case of a combine, the predetermined time is preferably about 0.5 seconds to 5 seconds.
(2) Auxiliary point: AP is the starting point, and a position a predetermined distance away on the target travel route: TL is assumed to be an estimated target point: VP. The predetermined distance may be set in advance, or may be selected automatically or artificially (by the driver or administrator) according to the state of harvested crops or the state of the field. In the case of a combine, the predetermined distance is preferably about 1 m to several meters.

The corrected azimuth calculation unit 9A calculates a corrected azimuth that eliminates the deviation between the estimated target point VP and the vehicle position. This corrected azimuth is a target steering azimuth (steering amount in steering control) for the vehicle body 10 to get on the target travel route TL. In this embodiment, as shown in FIG. 6, the corrected heading calculation unit 9A includes an estimated heading deviation calculator 90, a first controller 91, a second controller 92, and a calculator to calculate the corrected heading. a vessel 93;

The estimated heading deviation calculator 90 calculates the angle (indicated by β in FIG. 7) formed by the first auxiliary line AL1 and the virtual line RL as the estimated heading deviation. The first controller 91 uses the estimated heading deviation as an input parameter and outputs a first corrected heading that should be a provisional steering target of the vehicle body 10 . The first corrected heading is a steering heading in steering control that is calculated to eliminate the estimated heading deviation. Since the estimated heading deviation corresponds to the angle β for the vehicle body 10 to move toward the estimated target point VP, the output from the first controller 91 is preferably proportional to the estimated heading deviation that is the input. Therefore, in this embodiment, the first controller 91 is configured as a proportional controller.

The second controller 92 outputs a second corrected heading using the lateral deviation: d as an input parameter. The second controller 92 calculates a correction angle (indicated by α in FIG. 7) based on the lateral deviation d, and this second correction azimuth corresponds to this correction angle: α. is the steering direction in The second controller 92 calculates the steering azimuth for changing the orientation of the vehicle body 10 so as to reduce the lateral deviation d, and is configured as an integral controller in this embodiment. Of course, the second controller 92 may also be configured as a proportional controller.

The arithmetic unit 93 performs an addition operation of the first corrected azimuth and the second corrected azimuth, and outputs the corrected azimuth as a computation result. This addition operation corresponds to α+β if expressed in terms of angles with reference to FIG. This corrected azimuth is the output value of the corrected azimuth calculation unit 9A and is given to the control calculation unit 9B. As the addition operation in the arithmetic unit 93, weighting operation or the like may be used other than simple addition. Also, the second controller 92 may be omitted. In that case, the calculator 93 becomes unnecessary.

The control arithmetic unit 9B includes a calculator 95 and a steering controller 96 for outputting a control amount for the vehicle body 10 to travel along the target travel route TL. Steering controller 96 is configured as a PI or P controller. In this embodiment, the control computation unit 9B uses not only the corrected azimuth from the corrected azimuth computation unit 9A but also the current vehicle azimuth calculated by the vehicle azimuth calculation unit 41 as input parameters. This current vehicle body direction corresponds to the angle (indicated by γ in FIG. 7) formed by the virtual line: RL and the vehicle body direction line: DL. A computing unit 95 performs an addition operation of the corrected azimuth and the vehicle azimuth. This addition operation corresponds to .theta.(=.alpha.+.beta.+.gamma.) if expressed in terms of angles with reference to FIG. The computation output of the calculator 95 is given to the steering controller 96 as a control target value for the steering controller 96 . Furthermore, the output value from the steering controller 96 is given to the automatic cruise control section 512 as a control amount for steering.

Next, the calculation for deriving the force control amount by using the control amount given from the control calculation unit 9B as the input control amount, which is performed by the automatic travel control section 512, will be described with reference to FIGS. 8 and 9. FIG.

The automatic driving control section 512 converts the control amount (referred to as steering input) given from the control arithmetic unit 9B into 16 bits and outputs it as a steering output. In general, the steering input is evenly assigned to each bit to derive the steering output, as in the graph shown in FIG. In order to improve such calculations and achieve precise steering for small input control variables close to zero, calculations in which a bit expansion function is introduced are shown in FIG. Here, one bit, which corresponds to the minimum range of steering inputs, is further divided into four. As a result, even if a small control amount close to zero is input from the control arithmetic unit 9B, a small control output commensurate with it is derived. As a result, minute control signals can be output, realizing precise steering.

[Another embodiment]
(1) In the embodiment described with reference to FIG. 7, the estimated target point: the auxiliary point (starting point) used for estimating VP: AP moves from the reference point of the vehicle body 10: RP to the target travel route: TL. It was the point of intersection (projection point) between the dropped perpendicular line and the target travel route: TL. Instead of this, the intersection (projection point) of the line drawn from the reference point RP to the target travel route TL by plus or minus a predetermined angle to 90° with respect to the target travel route TL and the target travel route TL is the auxiliary point AP. may be At this time, the predetermined angle is an angle greater than 0 and up to several tens of degrees, and may be a fixed value, or may be changed manually or automatically depending on the vehicle speed and field conditions. Furthermore, when the intersection of the vehicle body direction line: DL and the target travel route: TL is located downstream of the auxiliary point: AP in the traveling direction of the vehicle body 10, the intersection of the vehicle body direction line: DL and the target travel route: TL may be used as an auxiliary point: AP.

(2) In the above-described embodiment, the substantial harvesting work is performed by running the combine along a straight running route. This linear travel route is not limited to one straight line. A curved path, a curved path with a large radius of curvature, or a meandering path may be used.

(3) In the above-described embodiment, the shape of the unworked area CA is a quadrangle, but it may be another polygon such as a triangle or a pentagon.

(4) The functional block groups of the control device 5 shown in FIGS. 5 and 6 are for the purpose of easy-to-understand explanation, and each functional block may be further divided, integrated, or omitted. Also, all or part of the functional blocks may be constructed in the general-purpose terminal 4 .

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

The control device according to the present invention can be used not only for a normal combine harvester but also for a self-removing combine harvester. can also be applied.

5: Control device 9A: Correction direction calculation unit 9B: Control calculation unit 10: Vehicle body 11: Traveling device 40: Vehicle position calculation unit 41: Vehicle direction calculation unit 42: Vehicle speed calculation unit 51: Travel control unit 511: Manual travel control Unit 512 : Automatic travel control unit 513 : Target travel route setting unit 56 : Lateral deviation calculation unit 57 : Target point estimation unit 65 : Manipulator 80 : Vehicle position detection unit 81 : Satellite positioning module 82 : Inertial measurement module 90 : Estimated heading deviation calculator 91 : First controller 92 : Second controller 93 : Calculator 95 : Calculator 96 : Steering controller

Claims (8)

A control device for a work vehicle that automatically travels along a target travel route,
a vehicle position calculation unit that calculates the vehicle position of the working vehicle;
a target point estimation unit that calculates an estimated target point on the target travel route after a predetermined time;
a corrected heading calculation unit that calculates a corrected heading that eliminates the deviation between the estimated target point and the vehicle position;
a control calculation unit that uses the corrected heading as an input parameter and outputs a control amount for controlling the work vehicle so as to reduce the deviation;
an estimated heading deviation calculator for calculating an angle between the target travel route and a straight line passing through the estimated target point and the vehicle position as an estimated heading deviation,
The corrected azimuth calculation unit includes a first controller that outputs a first corrected azimuth using the estimated azimuth deviation as an input parameter, and the controller calculates the corrected azimuth based on the first corrected azimuth. 2. The controller of claim 1 , wherein said first controller is a proportional controller. a lateral deviation calculator that calculates a lateral deviation as a distance from the vehicle position to the target travel route in a direction perpendicular to the direction of the target travel route;
The corrected azimuth calculation unit includes a second controller that outputs a second corrected azimuth using the lateral deviation as an input parameter, and the corrected azimuth is calculated based on the first corrected azimuth and the second corrected azimuth. 3. The control device according to claim 1 or 2 . 4. The controller of claim 3 , wherein said second controller is an integral controller. A vehicle speed calculation unit that calculates the vehicle speed of the work vehicle is provided,
The target point estimating unit sets a position of a point obtained by moving the target travel route at the vehicle speed for the predetermined time from a point projected from the vehicle position onto the target travel route as the estimated target point. 5. The control device according to any one of 1 to 4 . A vehicle body direction calculation unit for calculating a vehicle body direction indicating the direction of the vehicle body is provided,
6. The control device according to any one of claims 1 to 5 , wherein the control arithmetic unit further uses the vehicle body orientation as an input parameter. The control device according to any one of claims 1 to 6 , wherein the predetermined time is changed according to the state of the work vehicle. A control device for a work vehicle that automatically travels along a target travel route,
a vehicle position calculation unit that calculates the vehicle position of the working vehicle;
a target point estimating unit that calculates, as an estimated target point, a position that is a predetermined distance away on the target travel route from a point projected onto the target travel route from the vehicle position in the direction in which the work vehicle travels;
a corrected heading calculation unit that calculates a corrected heading that eliminates the deviation between the estimated target point and the vehicle position;
a control calculation unit that uses the corrected heading as an input parameter and outputs a control amount for controlling the work vehicle so as to reduce the deviation;
an estimated heading deviation calculator for calculating an angle between the target travel route and a straight line passing through the estimated target point and the vehicle position as an estimated heading deviation,
The corrected azimuth calculation unit includes a first controller that outputs a first corrected azimuth using the estimated azimuth deviation as an input parameter, and the controller calculates the corrected azimuth based on the first corrected azimuth.

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