JP2018166440A - Agricultural machine - Google Patents

Abstract

To provide an agricultural machine capable of controlling an attitude of a working machine by properly and selectively using an inclination sensor and an angular velocity sensor according to a state of attitudes of a car body.SOLUTION: A tractor 10 includes an inclination sensor 41 that detects an inclination angle of a car body 11. An angular velocity sensor 42 detects an inclination-angle velocity of the car body 11. An attitude stability determination part 53 detects a degree of attitude stability of the car body 11 in a stepwise manner. A valve control part 54 can control a rolling cylinder 24 so as to hold the attitude of a working machine. The valve control part 54 can change over, in order of descending degrees of attitude stability determined by the attitude stability determination part 53, among states of: controlling the rolling cylinder 24 on the basis of a determination value of the inclination sensor 41; controlling the rolling cylinder 24 on the basis of a value obtained by integrating a detection value of the angular speed sensor 42; and controlling the rolling cylinder 24 on the basis of the detection value of the angular speed sensor 42.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a farm work machine capable of controlling the attitude of a work machine.

  2. Description of the Related Art Conventionally, there is known a farm work machine configured to control the posture of a work machine based on a detection value of an inclination sensor or an angular velocity sensor provided on a vehicle body. Patent Documents 1 and 2 disclose this type of tractor.

  Patent Document 1 discloses a tractor in which a rotary tiller that is a ground working device is connected in a freely rolling manner. The tractor is provided with a rolling control means for operating the hydraulic cylinder so that the horizontal posture of the rotary tiller is maintained at a set angle. The rolling control means performs correction based on the detected value of the tilt sensor with reference to the integrated value obtained by integrating the detected value of the angular velocity sensor so that the detected tilt angle becomes a preset target set angle. Then, operate the hydraulic cylinder. In addition, the rolling control means is provided with a discrimination means for discriminating whether the attitude stability of the traveling machine body is high or low. The weighting ratio of the detection value of each sensor is changed so as to reduce the ratio.

  The tractor disclosed in Patent Document 2 is provided with a rolling control means as in Patent Document 1, but this rolling control means is configured such that the right and left inclination angle of the rotary tiller is a set angle based only on the detected value of the inclination sensor. The hydraulic cylinder is operated so as to be maintained. At this time, a disturbance value caused by the centrifugal force generated at the time of turning is calculated, and the disturbance value is subtracted from the detection value of the inclination sensor, so that the detection value of the inclination sensor is optimized.

Japanese Patent No. 3688211 Japanese Patent No. 4107589

  However, in the configurations of Patent Documents 1 and 2, when the stability of the vehicle body is low, the followability of the posture control of the work machine with respect to the change in the posture of the vehicle body may not be sufficient, and there remains room for improvement.

  The present invention has been made in view of the above circumstances, and the purpose thereof is agricultural work capable of controlling the attitude of the work implement by appropriately using the inclination sensor and the angular velocity sensor according to the attitude state of the vehicle body. Is to provide a machine.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to the viewpoint of this invention, the agricultural machine of the following structures is provided. In other words, the agricultural machine includes a vehicle body, an actuator, an inclination sensor, an angular velocity sensor, a posture stability determination unit, and a control unit. The vehicle body supports a work machine. The actuator can change a posture of the working machine with respect to the vehicle body. The tilt sensor detects a tilt angle of the vehicle body. The angular velocity sensor detects an inclination angular velocity of the vehicle body. The posture stability determination unit determines the posture stability of the vehicle body stepwise. The control unit can control the actuator so that the posture of the work implement is maintained. The control unit can switch between the first state, the second state, and the third state in descending order of the posture stability in accordance with the posture stability determined by the posture stability determination unit. In the first state, the control unit controls the actuator based on a detection value of the tilt sensor. In the second state, the control unit controls the actuator based on a value obtained by integrating the detection value of the angular velocity sensor. In the third state, the control unit controls the actuator based on a detection value of the angular velocity sensor.

  Accordingly, the left and right tilt posture of the work implement can be appropriately controlled by effectively exhibiting the characteristics of the tilt sensor and the angular velocity sensor in accordance with the situation related to the posture of the vehicle body.

  In the above-mentioned agricultural machine, the following configuration is preferable. That is, the posture stability determination unit determines that the posture stability is at the lowest level when the detection value of the angular velocity sensor exceeds a threshold value. The posture stability determination unit determines the posture stability when the detected value of the angular velocity sensor is equal to or less than the threshold value for a predetermined time when the current determination is a step other than the highest step. Is changed to a higher level.

  As a result, even when the left-right tilt posture of the vehicle body suddenly becomes unstable, it is immediately determined that the posture stability is at the lowest stage, so the control unit enters the third state, and the detected value of the angular velocity sensor Based on the above, it is possible to control the right / left inclined posture of the work implement with high responsiveness.

  In the above-mentioned agricultural machine, the following configuration is preferable. That is, this agricultural working machine includes a vehicle speed sensor that detects the traveling speed of the vehicle body. When the traveling speed detected by the vehicle speed sensor exceeds a threshold, the posture stability determination unit does not determine the posture stability at a stage corresponding to the first state.

  Thereby, when it is anticipated that the left-right inclination posture of the vehicle body will be unstable, the right-left inclination posture of the work implement can be controlled with emphasis on responsiveness.

  In the farm work machine, the posture stability determination unit determines that the posture stability is determined to correspond to the first state when the number of operations of the actuator in the most recent predetermined time exceeds a threshold value. Preferably not.

  Thereby, when the operation frequency of the actuator is high and the tendency of the left-right tilt posture of the vehicle body to be unstable, it is possible to control the left-right tilt posture of the work implement with emphasis on responsiveness.

  In the agricultural machine, the posture stability determination unit changes the determination of the posture stability to a higher level than the present when the change in the detected value of the tilt sensor in the most recent predetermined time is equal to or less than a threshold value. It is preferable to do.

  Thereby, a change in the inclination of the vehicle body can be detected and the posture stability can be appropriately determined.

  In the above-mentioned agricultural machine, the following configuration is preferable. In other words, the agricultural machine includes an acceleration sensor that detects the acceleration in the left-right direction of the vehicle body. If the magnitude of acceleration detected by the acceleration sensor is equal to or greater than a threshold, the posture stability determination unit changes the determination of the posture stability to a level lower than the current level.

  As a result, it is possible to detect the left-right direction shaking generated in the vehicle body at an early stage and to appropriately determine the posture stability.

  In the above-mentioned agricultural machine, the following configuration is preferable. In other words, the agricultural machine includes a turning detection unit that detects the degree of turning of the vehicle body. The posture stability determination unit does not determine the posture stability at a stage corresponding to the first state when the turning detection unit detects turning of the vehicle body.

  Thereby, when turning the vehicle body, it is possible to avoid using the detection value of the inclination sensor that is easily affected by the centrifugal force to control the left-right inclination posture of the work implement.

The side view which shows the working machine with which the tractor which concerns on one Embodiment of this invention is mounted | worn. The block diagram which shows the electrical structure for controlling the raising / lowering and right-and-left inclination attitude | position of a working machine. The figure which shows the change of the detected value of the inclination sensor and angular velocity sensor in a vehicle body rocking | fluctuation test. The flowchart which shows the process which an attitude | position stability determination part performs. The state transition diagram regarding the determination which an attitude | position stability determination part performs. The flowchart which shows the process which a valve control part performs. The state transition diagram regarding the determination which the attitude | position stability determination part in another embodiment performs.

  Next, embodiments of the invention will be described with reference to the drawings. FIG. 1 is a side view showing a tractor 10 and a work implement 3 to be attached according to an embodiment of the present invention. FIG. 2 is a block diagram showing an electrical configuration for controlling the vertical and horizontal tilt postures of the work machine 3.

  A tractor 10 shown in FIG. 1 is an agricultural working machine (working vehicle), and various working machines 3 such as a rotary, a loader, a plow, a box scraper and the like are mounted on a vehicle body 11 as necessary, and are supported by the vehicle body 11. Various operations can be performed by the machine 3. In FIG. 1, the example using a rotary tiller as the working machine 3 is shown. In the following description, “left side”, “right side”, and the like simply mean the left side and the right side in the direction in which the tractor 10 moves forward.

  As shown in FIG. 1, the tractor 10 includes a vehicle body 11, a pair of left and right front wheels 12, and a pair of left and right rear wheels 13. A bonnet 14 is disposed at the front of the vehicle body 11, and an engine 15 is disposed inside the bonnet 14.

  A mission case 16 is disposed between the pair of left and right rear wheels 13. The output of the engine 15 is shifted by a hydraulic-mechanical transmission disposed in the mission case 16 and transmitted to the rear wheel 13.

  In the rear part of the mission case 16, a lower link 18 is arranged in a pair of left and right, and one top link 19 is arranged. Further, a PTO shaft 20 is disposed so as to protrude from the rear portion of the mission case 16. The work machine 3 is connected to the lower link 18 and the top link 19 and is driven by the PTO shaft 20.

  A work implement lifting mechanism 25 and a work implement angle changing mechanism 26 are provided at the rear portion of the vehicle body 11.

  The work implement lifting mechanism 25 includes a pair of left and right lift arms 21 and a lift cylinder 22 configured as a hydraulic cylinder. The distal end of one of the left and right lift arms 21 is connected to one lower link 18 via a link member 23, and the distal end of the other lift arm 21 is connected to the other lower link 18 via a rolling cylinder 24 described later. It is connected. With this configuration, the height at which the work machine 3 is supported by the vehicle body 11 can be changed by driving the lift cylinder 22.

  The work machine angle changing mechanism 26 includes a rolling cylinder (actuator) 24 configured as a hydraulic cylinder. The rolling cylinder 24 is disposed so as to connect the right lift arm 21 and the right lower link 18 of the pair of left and right. With this configuration, by driving the rolling cylinder 24, it is possible to change the left-right inclination posture in which the work machine 3 is supported with respect to the vehicle body 11.

  A cabin 31 for an operator to board is disposed above the mission case 16 and behind the bonnet 14. A driver seat 32 is provided inside the cabin 31, and various operation tools are provided in the vicinity of the driver seat 32.

  More specifically, a steering handle 33 for an operator to steer is disposed in front of the driver seat 32.

  A work implement lifting lever 34, an inclination angle setting dial 35, and a control mode changeover switch 36 are disposed in the vicinity of the right armrest of the driver seat 32.

  The work implement elevating lever 34 is a lever-like operation member, and can instruct the height of the work implement 3 in a stepless manner. When the operator operates the work implement lifting lever 34 in the front-rear direction, the operation is detected by a sensor (for example, a potentiometer) (not shown). The work implement lifting mechanism 25 operates in accordance with the detection result output from the sensor, whereby the work implement 3 can be raised and lowered.

  The tilt angle setting dial 35 is a dial-like operation member, and can instruct the left and right tilt angles of the work implement 3 in a stepless manner within a predetermined range of right-down, horizontal-up. When the operator rotates the tilt angle setting dial 35, the operation is detected by a sensor (for example, a potentiometer) (not shown). The work implement angle changing mechanism 26 operates according to the detection result output by the sensor, whereby the left / right inclination angle of the work implement 3 can be changed.

  The control mode changeover switch 36 is configured as a push button switch, for example, and can switch a mode for controlling the left and right inclination angle of the work implement 3. When the operator presses the control mode changeover switch 36, the control mode related to the left / right inclination of the work machine 3 can be switched between the automatic mode and the manual mode. Details of the automatic mode and the manual mode will be described later.

  As shown in FIG. 2, the tractor 10 acquires an inclination sensor 41, an angular velocity sensor 42, a vehicle speed in order to automatically control the inclination of the work implement 3 by acquiring the right / left inclination posture and the angular velocity of the right / left inclination direction of the vehicle body 11. A sensor 43, a rudder angle sensor (turn sensor) 44, and an acceleration sensor 45 are provided. All of these sensors are electrically connected to a work machine controller 48 described later. However, the vehicle speed sensor 43, the steering angle sensor 44, and the acceleration sensor 45 are not drawn in FIG.

  The tilt sensor 41 is attached to an appropriate position of the mission case 16. Although the tilt sensor 41 has a known configuration and will not be described in detail, the tilt sensor 41 includes a fixed electrode and a movable electrode attached to the cantilever, and is movable by gravity as the element is tilted. By detecting the movement of the electrode as a change in electrostatic capacitance, the horizontal inclination of the vehicle body 11 is detected. However, the tilt sensor is not limited to the above. For example, the tilt sensor may include a chamber in which a liquid is sealed, and may detect a change in the liquid level due to the tilt as a change in capacitance. Furthermore, a known weight type tilt sensor may be used.

  The angular velocity sensor 42 is disposed inside the cabin 31 below the driver seat 32 (near the position of the center of gravity of the tractor 10). The angular velocity sensor 42 is configured as a known vibration gyro sensor, and detects the change in the lateral inclination of the vehicle body 11 (angular velocity) by detecting the magnitude of the Coriolis force generated when the vibrating element is rotated. ) Can be detected.

  The vehicle speed sensor 43 shown in FIG. 2 is disposed at an appropriate position of the vehicle, for example, the axle of the front wheel 12. The vehicle speed sensor 43 is configured to generate a pulse corresponding to the rotation of the axle, for example. Information on the traveling speed obtained by the vehicle speed sensor 43 is output to the work machine controller 48. However, the vehicle speed sensor 43 can be configured to obtain the traveling speed by calculation, for example, by detecting the transition of the position of the vehicle body 11 by GNSS positioning.

  The rudder angle sensor 44 is a sensor that detects the rudder angle of the front wheel 12 and is disposed at an appropriate position of the vehicle, for example, a king pin (not shown) that is a turning axis of the front wheel 12. Information on the rudder angle obtained by the rudder angle sensor 44 is output to the work machine controller 48. However, the steering angle sensor 44 may be arranged on the steering handle 33, for example, and the steering angle sensor 44 may detect the angle at which the steering handle 33 is operated.

  The acceleration sensor 45 is configured as a sensor that detects lateral acceleration applied to the vehicle body 11. The acceleration sensor 45 can be configured to include a fixed electrode and a movable electrode, similarly to the tilt sensor 41 described above.

  As shown in FIG. 2, a lift control valve 61 is disposed between a lift cylinder 22 provided in the work implement lifting mechanism 25 and a hydraulic pump (not shown). The lift control valve 61 is configured as an electromagnetic valve and is electrically connected to the work machine controller 48.

  Further, a rolling control valve 62 is disposed between the rolling cylinder 24 provided in the work machine angle changing mechanism 26 and the hydraulic pump. The rolling control valve 62 is configured as an electromagnetic valve and is electrically connected to the work machine controller 48.

  The work machine controller 48 includes a lift control unit 51 and a rolling control unit 52. Further, the rolling control unit 52 includes a posture stability determination unit 53 and a valve control unit (control unit) 54.

  More specifically, the work machine controller 48 is configured as a computer, and includes a calculation unit such as a CPU and a storage unit including a ROM, a RAM, and the like. These hardware and the work implement control program stored in the storage unit cooperate to make the work implement controller 48 a lift control unit 51, a rolling control unit 52, a posture stability determination unit 53, and It can function as the valve control unit 54 or the like.

  The lift control unit 51 controls the lift cylinder 22 via the lift control valve 61 so that the work implement 3 is supported at a height instructed by the operator by the work implement lift lever 34.

  The rolling control unit 52 controls the rolling cylinder 24 via the rolling control valve 62 so that the work implement 3 is supported at the left and right inclination angles designated by the operator with the inclination angle setting dial 35 under predetermined conditions.

  Specifically, the rolling control unit 52 can control the left and right posture of the work implement 3 in one mode selected from two modes, an automatic mode and a manual mode. Each mode will be described below.

  In the automatic mode, when the operator operates the tilt angle setting dial 35 to indicate an arbitrary angle and operates the work implement lifting lever 34 to lower the work implement 3, regardless of the inclination of the vehicle body 11, It is possible to control the right / left tilt posture of the work machine 3 so as to be the designated angle with respect to the horizontal (that is, with respect to the direction perpendicular to the gravitational acceleration). However, when the work implement 3 is raised, the work implement 3 is controlled to be parallel to the vehicle body 11.

  In this automatic mode, for example, if the operator indicates the level with the tilt angle setting dial 35, the field may be uneven or weak, or one wheel may fall on the cultivated land. Even when 11 is tilted, the work implement 3 is controlled so as to always maintain a horizontal posture. Therefore, flat tillage is realized and the cultivator is stabilized.

  In the manual mode, the operation of the tilt angle setting dial 35 is invalidated. Regardless of whether the work machine 3 is in the raised position or the lowered position, the operator changes the tilt posture of the work machine 3 by operating a tilt angle setting member (not shown) different from the tilt angle setting dial 35. can do.

  Next, the tilt sensor 41 and the angular velocity sensor 42 used for realizing control of the left and right tilt posture when the work implement 3 is lowered in the automatic mode will be described.

  Although the tilt sensor 41 can detect the angle (absolute tilt angle) of the vehicle body 11 with respect to the direction of the gravitational acceleration of the earth, the change of the detected value does not follow the change of the tilt angle quickly. Further, the detected value of the tilt sensor 41 is easily influenced by external force such as centrifugal force accompanying the turning of the vehicle body 11.

  On the other hand, the angular velocity sensor 42 can quickly detect a change in the inclination angle of the vehicle body 11, and the detected value is not easily influenced by an external force. However, the angular velocity sensor 42 can detect a change in the tilt angle but cannot determine an absolute tilt angle.

  FIG. 3 shows changes in the output values of the tilt sensor 41 and the angular velocity sensor 42 when the vehicle body 11 is placed on a swing tester and the left-right tilt posture is periodically changed between right-down and right-up. Two graphs are shown. In this test, the support height of the left front wheel 12 and the rear wheel 13 is made constant, and the support height of the right front wheel 12 and the rear wheel 13 is simply oscillated with a predetermined amplitude around the same height as the left. ing.

  The vertical axis of the upper graph is the height of the right front wheel 12 and the rear wheel 13 and substantially means the left-right inclined posture of the vehicle body 11. The vertical axis of the lower graph represents the output values of the tilt sensor 41 and the angular velocity sensor 42. The horizontal axes of the two graphs are both time axes, and time corresponds to the upper and lower graphs.

  As can be seen from this graph, the timing at which the peak of the output value of the tilt sensor 41 appears is somewhat delayed from the peak of the actual tilt posture change. On the other hand, in consideration of the fact that the peak of velocity appears in a simple vibration when the displacement is zero, it can be seen that the detection delay of the angular velocity sensor 42 is considerably smaller than that of the tilt sensor 41.

  As described above, the angular velocity sensor 42 can detect a change in angle, but cannot detect the angle itself. Therefore, although it is possible to control the left-right posture of the work machine 3 so as to cancel the change in the left-right posture of the vehicle body 11 from a certain point in time, the accuracy is not high. Further, by performing an appropriate stabilization process (for example, a low-pass filter process) on the detection value of the angular velocity sensor 42 and integrating the detected value, it is possible to obtain a right / left inclined posture with a certain degree of reliability. Along with the stabilization process, a detection delay occurs that is not as great as the tilt sensor 41.

  Therefore, the rolling control unit 52 included in the work machine controller 48 of the present embodiment is configured as follows based on the properties of the detection values as described above.

  More specifically, the rolling control unit 52 includes a posture stability determination unit 53 and a valve control unit 54 as shown in FIG.

  The posture stability determination unit 53 determines the posture stability indicating whether the left and right posture of the vehicle body 11 is in a stable situation with little fluctuation or an unstable situation with many fluctuations based on the detection value of the angular velocity sensor 42 and the like. Judgment is made in three stages of “high”, “medium”, and “low”. The highest level is “high” and the lowest level is “low”.

  Based on the determination result of the posture stability determination unit 53, the valve control unit 54 is based on one of the detection value of the angular velocity sensor 42, the integral value of the detection value of the angular velocity sensor 42, and the detection value of the tilt sensor 41. The rolling cylinder 24 is extended and retracted via the rolling control valve 62 so that the working machine 3 assumes a left-right inclined posture at an angle designated by the inclination angle setting dial 35 with respect to the horizontal.

  Next, processing of the posture stability determination unit 53 will be described with reference to FIG. FIG. 4 is a flowchart showing processing performed by the posture stability determination unit 53.

  First, the posture stability determination unit 53 sets the determination result of posture stability to “low” which is an initial value (step S101), and then the state in which the detected value of the angular velocity sensor 42 is less than a predetermined threshold is predetermined. It is determined whether or not the time has continued (step S102).

  If the detected value of the angular velocity sensor 42 is equal to or greater than the threshold value, or is less than the threshold value, but the time during which the state continues is shorter than the predetermined time, the determination in step S102 is repeated.

  If it is determined in step S102 that the detected value of the angular velocity sensor 42 is less than the predetermined threshold value for a predetermined time or longer, the posture stability determination unit 53 changes the determination result of the posture stability from “low” to “ It changes to “medium” (step S103).

  Thereafter, the posture stability determination unit 53 determines whether or not the detection value of the angular velocity sensor 42 is equal to or greater than the threshold value (step S104). If the detected value of the angular velocity sensor 42 is equal to or greater than the threshold value, the process returns to step S101, and as a result, the determination result of the posture stability is changed to “low”.

  If it is determined in step S104 that the detected value of the angular velocity sensor 42 is less than the predetermined threshold value, the posture stability determination unit 53 determines whether or not the traveling speed of the vehicle body 11 satisfies a predetermined condition (step S104). S105). Specifically, this condition is that the traveling speed detected by the vehicle speed sensor 43 is less than a predetermined value, and the number of operations of the rolling cylinder 24 (that is, the operating frequency of the rolling cylinder 24) in a certain period of time is predetermined. This means that it is less than the number of times and that the detected value of the rudder angle sensor 44 is near neutral (in other words, the turning of the vehicle body 11 is not detected). If the condition is not satisfied, the process returns to step S104.

  If it is determined in step S105 that the above condition is satisfied, the posture stability determination unit 53 further determines whether or not the state in which the detected value of the angular velocity sensor 42 is less than a predetermined threshold continues for a predetermined time. (Step S106). When the time during which the state of being less than the threshold value of the angular velocity sensor 42 continues is shorter than the predetermined time, the process returns to step S104.

  If it is determined in step S106 that the detected value of the angular velocity sensor 42 is less than the predetermined threshold value for a predetermined time or longer, the posture stability determination unit 53 changes the determination result of the posture stability from “medium” to “ It is changed to “high” (step S107).

  Thereafter, the posture stability determination unit 53 determines whether or not the detection value of the angular velocity sensor 42 is equal to or greater than the threshold value (step S108). If the detected value of the angular velocity sensor 42 is equal to or greater than the threshold value, the process returns to step S101, and as a result, the determination result of the posture stability is changed to “low”. If the detected value of the angular velocity sensor 42 is less than the threshold value, the determination in step S108 is repeated.

  By performing the above processing, the posture stability determination unit 53 outputs “low” as the determination result of the posture stability when the detected value of the angular velocity sensor 42 is equal to or greater than the threshold value as shown in FIG. When a state in which the detection value of the angular velocity sensor 42 is less than the threshold value has elapsed for a predetermined time, the output determination result changes from “low” to “medium”, and when a similar state further elapses while satisfying the conditions such as the vehicle speed Thus, the control that the output determination result is changed from “medium” to “high” is realized.

  Next, the processing of the valve control unit 54 performed based on the determination result of the posture stability determination unit 53 will be described with reference to FIG. FIG. 6 is a flowchart showing processing performed by the valve control unit 54.

  First, the valve control unit 54 determines whether or not the determination result of the posture stability output from the posture stability determination unit 53 is “high” (step S201). When the determination result is “high”, the valve control unit 54 controls the rolling control valve 62 based on the detection value of the inclination sensor 41 (first state, step S202). Thereafter, the process returns to step S201.

  If the determination result in step S201 is not “high”, the valve control unit 54 determines whether the determination result of the posture stability output from the posture stability determination unit 53 is “medium” (step S201). S203). When the determination result is “medium”, the valve control unit 54 controls the rolling control valve 62 based on the result (integrated value) obtained by integrating the detection value of the angular velocity sensor 42 (second state, step S204). Thereafter, the process returns to step S201.

  If the determination result in step S203 is not “medium”, it means that the determination result of the posture stability is “low”. In this case, the valve control unit 54 controls the rolling control valve 62 based on the detection value of the angular velocity sensor 42 (third state, step S205). Thereafter, the process returns to step S201.

  In this way, the valve control unit 54 determines the detection value of the angular velocity sensor 42 based on the detection value of the inclination sensor 41 when the determination result of the posture stability determination unit 53 is “high”, and when the determination result is “medium”. If it is “low” based on the integrated value, the left and right tilt control of the work implement 3 is performed based on the detection value of the angular velocity sensor 42.

  That is, when the posture stability is “high”, the left-right tilt posture of the vehicle body 11 is stable, and even if a posture detection delay occurs, the posture maintenance of the work machine 3 is hardly affected. On the other hand, since the posture of the vehicle body 11 is unstable when the posture stability is “low”, it is necessary to quickly follow the posture change of the vehicle body 11 to control the tilt posture of the work machine 3.

  In this regard, in this embodiment, when the posture stability is “high”, the detection value of the highly reliable tilt sensor 41 is used for posture control of the work implement 3. When the posture stability is “low”, the detection value of the angular velocity sensor 42 with a small detection delay is used for posture control of the work implement 3. When the posture stability is “medium”, it is an intermediate situation, and therefore, a value obtained by integrating the detected values of the angular velocity sensor 42 is used for posture control of the work implement 3. Thereby, the detection characteristics of the tilt sensor 41 and the angular velocity sensor 42 can be effectively exhibited according to the situation, and the left and right tilt posture of the work implement 3 can be appropriately controlled.

  In addition, the determination in step S105 is performed in the posture stability determination process in FIG. 4, so that the traveling speed of the vehicle body 11 detected by the vehicle speed sensor 43 is equal to or higher than a predetermined threshold, or the operating frequency of the rolling cylinder 24 is predetermined. If the detected value of the angular velocity sensor 42 is less than the threshold value, the determination of the posture stability does not become “high” even when the state where the detected value of the angular velocity sensor 42 is less than the threshold value continues for a predetermined time. As a result, when the left-right tilt posture of the vehicle body 11 is expected to become unstable or when an unstable tendency is detected, the responsiveness to changes in the left-right tilt posture of the vehicle body 11 is emphasized. Thus, the right / left inclined posture of the work machine 3 can be controlled.

  Further, when the detected value of the rudder angle sensor 44 is not near neutral (in other words, when turning of the vehicle body 11 is detected) in step S105, the detected value of the angular velocity sensor 42 is similarly less than the threshold value. Even when the period of time continues for a predetermined time, the determination of the posture stability does not become “high”. Thereby, it is possible to prevent the left and right tilt posture of the work implement 3 from being controlled using the detection value of the tilt sensor 41 that is easily affected by the centrifugal force due to turning.

  As described above, the tractor 10 of this embodiment includes the vehicle body 11, the rolling cylinder 24, the tilt sensor 41, the angular velocity sensor 42, the posture stability determination unit 53, and the valve control unit 54. . The vehicle body 11 supports the work machine 3. The rolling cylinder 24 can change the posture of the work machine 3 with respect to the vehicle body 11. The tilt sensor 41 detects the tilt angle of the vehicle body 11. The angular velocity sensor 42 detects the inclination angular velocity of the vehicle body 11. The posture stability determination unit 53 determines the posture stability of the vehicle body 11 in stages. The valve control unit 54 can control the rolling cylinder 24 so that the posture of the work machine 3 is held in the posture specified by the tilt angle setting dial 35. The valve control unit 54 can switch between the first state, the second state, and the third state in descending order of the posture stability determined by the posture stability determination unit 53. In the first state, the valve control unit 54 controls the rolling cylinder 24 based on the detection value of the tilt sensor 41. In the second state, the valve control unit 54 controls the rolling cylinder 24 based on a value obtained by integrating the detection value of the angular velocity sensor 42. In the third state, the valve control unit 54 controls the rolling cylinder 24 based on the detection value of the angular velocity sensor 42.

  Thus, the left and right tilt posture of the work implement 3 can be appropriately controlled by effectively exhibiting the characteristics of the tilt sensor 41 and the angular velocity sensor 42 according to the situation related to the posture of the vehicle body 11.

  Further, in the tractor 10 of the present embodiment, the posture stability determination unit 53 determines that the posture stability is “low” when the detection value of the angular velocity sensor 42 exceeds the threshold value. The posture stability determination unit 53 determines the posture stability when the detection value of the angular velocity sensor 42 is equal to or less than the threshold value for a predetermined time when the current determination is “low” or “medium”. Is changed to a higher level.

  Thereby, even when the left-right inclined posture of the vehicle body 11 suddenly becomes unstable, the posture stability immediately becomes “low”, so the left-right inclined posture of the work implement 3 is changed based on the detection value of the angular velocity sensor 42. It can be controlled with good responsiveness.

  Further, the tractor 10 of the present embodiment includes a vehicle speed sensor 43 that detects the traveling speed of the vehicle body 11. The posture stability determination unit 53 does not set the posture stability determination to “high” when the traveling speed detected by the vehicle speed sensor 43 exceeds the threshold.

  Thereby, when it is anticipated that the left-right inclination posture of the vehicle body 11 will become unstable, the right-left inclination posture of the work machine 3 can be controlled with emphasis on responsiveness.

  Further, in the tractor 10 of the present embodiment, the posture stability determination unit 53 does not make the posture stability determination “high” when the operation frequency of the rolling cylinder 24 is equal to or higher than the threshold value.

  Thereby, when the tendency for the left-right inclination posture of the vehicle body 11 to be unstable is recognized, the right-left inclination posture of the work machine 3 can be controlled with emphasis on responsiveness.

  In addition, the tractor according to the present embodiment includes a steering angle sensor 44 that detects the degree of turning of the vehicle body 11. The posture stability determination unit 53 does not set the posture stability determination to “high” when the turning of the vehicle body 11 is detected by the steering angle sensor 44.

  Thereby, when turning the vehicle body 11, it is possible to avoid controlling the right and left tilt posture of the work implement 3 using the detection value of the tilt sensor 41 that is easily affected by the centrifugal force.

  Next, another embodiment will be described. FIG. 7 is a state transition diagram regarding determination of posture stability in a tractor according to another embodiment. In the description of the present embodiment, the same or similar members as those of the above-described embodiment may be denoted by the same reference numerals in the drawings, and description thereof may be omitted.

  In the present embodiment, the posture stability determination performed by the posture stability determination unit 53 is performed based on the detection values of the inclination sensor 41 and the acceleration sensor 45 instead of the angular velocity sensor 42, unlike the above-described embodiment. Yes.

  That is, in this embodiment, as shown in FIG. 7, the posture stability determination unit 53 sets the posture stability determination result to “low” when the change of the tilt sensor 41 in the latest predetermined time is less than the threshold. Change from “Medium” or “Medium” to “High”.

  On the other hand, when the detected value of the acceleration sensor 45 is equal to or greater than the threshold value, the posture stability determination unit 53 changes the posture stability determination result from “high” to “medium” or from “medium” to “low”. change.

  Even with the above configuration, the posture stability of the vehicle body 11 can be determined satisfactorily.

  As described above, in the tractor of the present embodiment, the posture stability determination unit 53 determines the posture stability currently when the change in the detected value of the tilt sensor 41 during the most recent predetermined time is equal to or less than the threshold value. Change to a higher level.

  Thereby, the change in the inclination of the vehicle body 11 can be detected and the posture stability can be appropriately determined.

  In addition, the tractor according to the present embodiment includes an acceleration sensor 45 that detects acceleration in the left-right direction of the vehicle body 11. If the magnitude of acceleration detected by the acceleration sensor 45 is equal to or greater than the threshold value, the posture stability determination unit 53 changes the posture stability determination to a level lower than the current level.

  As a result, it is possible to detect the left-right direction shaking generated in the vehicle body 11 at an early stage and to appropriately determine the posture stability.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  In the flowchart of FIG. 4, when the determination of the posture stability is “high”, if the condition described in step S <b> 105 is not satisfied, the determination can be changed to change to “medium”. .

  In the state transition diagram of FIG. 7, for example, when the state where the acceleration detected by the acceleration sensor 45 is less than the threshold value continues for a predetermined time or more, the posture stability determination is changed from “low” to “medium”, or It can also be configured to change from “medium” to “high”.

  The tractor 10 is provided with a tilt sensor that detects the right / left tilt posture of the work implement 3, and the rolling control unit 52 controls the left / right tilt posture of the work implement 3 based on the detected value of the tilt of the work implement 3 as well as the vehicle body 11. It can also be configured to.

  The posture stability determined by the posture stability determination unit 53 is not limited to three levels of “high”, “medium”, and “low”, but can be changed to be determined in four or more levels, for example.

  The tilt angle setting dial 35 may be omitted, and the valve control unit 54 may control the right / left tilt posture of the work implement 3 so that the posture of the work implement 3 is always kept horizontal (that is, vertical to the gravitational acceleration). .

  The horizontal control of the work machine 3 described above can be applied to a harrow, a laser leveler, or the like, which is a work machine dedicated to plowing, in addition to a rotary tiller. The present invention can also be applied to farm work machines other than tractors, such as rice transplanters, transplanters, sprayers, and the like.

3 Working machine 11 Car body 24 Rolling cylinder (actuator)
41 Inclination sensor 42 Angular velocity sensor 43 Vehicle speed sensor 44 Rudder angle sensor (turn detection unit)
45 Acceleration sensor 53 Posture stability determination unit 54 Valve control unit (control unit)

Claims (7)

A vehicle body that supports the work implement;
An actuator capable of changing the attitude of the working machine relative to the vehicle body;
An inclination sensor for detecting an inclination angle of the vehicle body;
An angular velocity sensor for detecting an inclination angular velocity of the vehicle body;
A posture stability determination unit for stepwise determining the posture stability of the vehicle body;
A control unit capable of controlling the actuator so that the posture of the working machine is maintained;
With
According to the posture stability determined by the posture stability determination unit, the control unit, in order from the highest posture stability,
A first state in which the actuator is controlled based on a detection value of the tilt sensor;
A second state in which the actuator is controlled based on an integrated value detected by the angular velocity sensor;
A third state in which the actuator is controlled based on a detection value of the angular velocity sensor;
Agricultural machine characterized by being switchable. The agricultural machine according to claim 1,
The posture stability determination unit determines that the posture stability is the lowest when the detection value of the angular velocity sensor exceeds a threshold value,
The posture stability determination unit determines the posture stability when the detected value of the angular velocity sensor is equal to or less than the threshold value for a predetermined time when the current determination is a step other than the highest step. Agricultural machine characterized by changing to a higher stage than present. The agricultural machine according to claim 1 or 2,
A vehicle speed sensor for detecting the traveling speed of the vehicle body;
The posture stability determination unit does not determine the posture stability at a stage corresponding to the first state when the traveling speed detected by the vehicle speed sensor exceeds a threshold value. Agricultural working machine according to any one of claims 1 to 3,
Agricultural work characterized in that the posture stability determination unit does not determine the posture stability at a stage corresponding to the first state when the number of operations of the actuator in the most recent predetermined time exceeds a threshold value. Machine. The agricultural machine according to claim 1,
The posture stability determination unit changes the determination of the posture stability to a higher level than the present when the change in the detected value of the tilt sensor in the most recent predetermined time is equal to or less than a threshold value. Machine. Agricultural working machine according to any one of claims 1 to 5,
An acceleration sensor for detecting lateral acceleration of the vehicle body;
The posture stability determination unit is configured to change the determination of the posture stability to a level lower than the current level when the magnitude of acceleration detected by the acceleration sensor is equal to or greater than a threshold value. Agricultural working machine according to any one of claims 1 to 6,
A turning detection unit for detecting the degree of turning of the vehicle body;
The farm work machine characterized in that the posture stability determination unit does not determine the posture stability at a stage corresponding to the first state when the turning detection unit detects turning of the vehicle body.

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