JP3690187B2 - Horizontal control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a horizontal control device, and more particularly to a horizontal control device such as an agricultural tractor or a riding management machine.
[0002]
[Prior art and problems to be solved by the invention]
In agricultural work vehicles such as agricultural tractors and riding management machines, a work machine such as a rotary is connected to the rear part of the machine via a link mechanism, and the rolling angle of the work machine relative to the machine is changed between the machine and the machine. There is known an actuator provided with a horizontal control device for automatically adjusting the rolling angle of the work implement by providing an inclination adjusting dial or the like for setting the rolling angle of the work implement on the machine body.
[0003]
In this horizontal control device, a sensor for detecting the rolling angle of the work machine is provided between the machine body and the work machine, and a tilt sensor for detecting the rolling angle of the machine body is provided in the machine body, and based on the detection value of each sensor. Calculate the rolling angle of the machine and the rolling angle of the work machine, and output a drive signal to the actuator to keep the rolling angle of the work machine horizontal regardless of the attitude of the machine, or the rolling angle of the machine and the work machine The actuator is controlled so as to be driven in order to maintain the rolling angle in parallel.
[0004]
In general, a tilt sensor is configured to suspend a pendulum that always faces in a vertical direction in a casing and detect a change in the angle of the right and left tilt of the casing attached to the fuselage with respect to the pendulum. For example, when the airframe starts to tilt in the lower right direction, the pendulum is relatively left on the left side. Therefore, the tilt sensor outputs a detection signal in the reverse direction immediately after the start of the tilt of the aircraft, and the response of detecting the tilt of the aircraft quickly is not good due to the time delay in the output of the detection signal.
[0005]
On the other hand, a method of providing a rolling angular velocity sensor for detecting the rolling angular velocity of the aircraft and calculating the rolling angle of the aircraft from the detection value of the rolling angular velocity sensor is also conceivable. However, various noises are generated depending on the traveling conditions and field conditions such as the traveling speed of the aircraft, the hardness of the field, or the lug pattern of the tire, and the output signal of the rolling angular velocity sensor continuously changes in small increments. In order to adjust the rolling angle of the work implement in synchronization with the output change of the rolling angular velocity sensor, an actuator capable of providing a variable speed with no response delay is required, which makes the configuration complicated and extremely expensive.
[0006]
The vibration noise also changes depending on the traveling speed of the aircraft, and the vibration noise increases as the traveling speed increases. In addition, for example, when removing or attaching the work machine, the rolling angular velocity sensor detects the rolling angular speed of the machine when vibration such as shaking the work machine to adjust the joint part is applied while stopping the machine or running at a slow speed. If the horizontal control signal is output, the working machine suddenly starts moving regardless of the operator's intention, which is dangerous.
[0007]
Therefore, when the actuator provided between the machine and the work machine is driven and the rolling angle of the work machine is adjusted to perform the horizontal control, the work machine is prevented from overshooting and response delay due to the rolling of the machine, and the machine body The technical problem to be solved in order to adjust the output of the horizontal control signal based on the rolling angular velocity sensor arises according to the travel speed of the vehicle, and the present invention aims to solve this problem.
[0008]
[Means for Solving the Problems]
The present invention has been proposed to achieve the above object, and a work machine is connected to the rear part of the machine body via a link mechanism, and the rolling angle of the work machine relative to the machine body is changed between the machine body and the work machine. A horizontal control device comprising an actuator and a means for detecting a rolling angle of the work machine relative to the machine body, a tilt sensor for detecting the rolling angle of the work machine on the machine body, and a tilt setting means for setting the rolling angle of the work machine a is a rolling angular velocity detection means when airframe該機body is rolling, and means for detecting the running speed of the aircraft is provided, a peak value of the right angular velocity by the rolling angular velocity detection means and left angular velocity of the peak value Is continuously measured for a predetermined time, and the neutral position of the rolling angular velocity detecting means is set from the average value of each peak value, and a predetermined rule is set for the neutral position. When a larger rolling angular velocity is detected, a horizontal control signal of the work implement is output based on the detection value of the rolling angular velocity detection means, and when the detection value of the rolling angular velocity detection means is within the specified value, the tilt sensor A level control signal of the work machine is output based on the detected value, and the level of the specified value is corrected according to the level of the speed of the machine. A horizontal control device configured not to output a horizontal control signal based on a detection value of the rolling angular velocity detection means when the value is below a certain value is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 show a small tractor 10 as an example of a work vehicle, and a rotary work machine 12 is connected to the rear part of the machine body via a link mechanism 11. In the vicinity of the driver's seat 13, a position lever 15 that is a lifting / lowering position setting means for the work implement, a tilling depth adjustment dial 16 that is a working depth setting means for the work implement, and an inclination that is an inclination setting means for setting the rolling angle of the work implement An adjustment dial 17 and the like are provided.
[0010]
On the other hand, in addition to a transmission gear mechanism (not shown), the transmission case 18 is provided with a vehicle speed sensor 40 as means for detecting the traveling speed of the airframe. An inclination sensor 41 that is a means for detecting the rolling angle of the airframe and a means for detecting the angular velocity when the airframe is pitched are located at the substantially upper central portion in the vicinity of the rear axle 19 on the upper surface of the transmission case 18. A pitching angular velocity sensor 42 and a rolling angular velocity sensor 43, which is a means for detecting an angular velocity when the airframe rolls, are integrally stored in a case 44.
[0011]
The link mechanism 11 includes a top link 20 and left and right lower links 21, 21, and the ends of the left and right lift arms 22, 22 and the lower links 21, 21 are connected by lift rods 23, 23 to drive the lift cylinder 24. By rotating the lift arm 22, the lower links 21, 21 move up and down via the lift rods 23, 23. Thus, the rotary working machine 12 moves up and down with the tip ends of the lower links 21 and 21 as the center of rotation.
[0012]
A lift arm angle sensor 25 is provided at the rotation base of the lift arm 22 as means for detecting the lift position of the work implement. The lift arm angle sensor 25 detects the rotation angle of the lift arm 22, and the controller 50. To calculate the elevation height of the rotary working machine 12. Further, a rear cover 27 is attached to the rear end portion of the main cover 26 of the rotary work machine 12 so as to be rotatable up and down, and a rotation angle of the rear cover 27 is detected by a rear cover sensor 28, and the controller 50 detects the rotation of the rotary work machine 12. Calculate tillage depth.
[0013]
On the other hand, as an actuator for changing the rolling angle of the rotary working machine 12 with respect to the machine body, a rolling cylinder 30 is provided in the middle of either the left or right lift rod 23, and the rolling cylinder 30 is expanded or contracted to increase or decrease the lift amount of the lower link 21. By changing the angle, the inclination of the rotary working machine 12 with respect to the machine body in the left-right direction can be changed.
[0014]
As a means for detecting the rolling angle of the rotary working machine 12 with respect to the machine body, a stroke sensor 31 is provided adjacent to the rolling cylinder 30, and the expansion / contraction length of the rolling cylinder 30 is detected by the stroke sensor 31. The rolling angle of the rotary working machine 12 is calculated by the controller 50, and the rolling cylinder 30 is driven according to the set value of the tilt adjusting dial 17 so that the horizontal working of the rotary working machine 12 can be performed.
[0015]
Here, a steering handle 32 which is a steering operation portion of the fuselage is provided in front of the driver's seat 13, and a forward / reverse switching lever 33 is provided in the vicinity of the steering handle 32, and the forward / backward switching lever 33 is operated. Thus, the driving force transmitted to the rear wheel 34 is reversed so that the traveling direction of the aircraft can be selected. In addition, a shift lever 35 is provided at the front lower portion of the driver's seat 13 and left and right brake pedals 36 and 36 that can be stepped independently are provided. The rotation operation of the steering handle 32 is transmitted to the steering device 37, and the front wheel 38 turns according to the steering amount. The steering amount of the front wheel 38 is detected by a front wheel break angle sensor 39.
[0016]
FIG. 3 is a block diagram of the control system. The working depth target value of the rotary working machine 12 is set by the working depth adjustment dial 16, and the lift position of the rotary working machine 12 is calculated by the detection signal of the lift arm angle sensor 25. At the same time, the rear cover sensor 28 detects the rotation angle of the rear cover 27 and calculates the working depth of the rotary working machine. Then, in order to maintain the rotation angle of the rear cover 27 at a predetermined angle corresponding to the working depth target value set by the working depth adjustment dial 16, to the raising solenoid or the lowering solenoid of the electromagnetic control valve that drives the lift cylinder 24. A control signal is output from the controller 50. Therefore, the lift arm 22 is turned up and down to move the rotary work machine 12 up and down, and the rear cover 27 is turned and the detection value of the rear cover sensor 28 is controlled to coincide with the tilling target value.
[0017]
On the other hand, the tilt adjustment dial 17 allows the operator to arbitrarily set the rolling angle of the rotary working machine 12. The rolling angle of the machine relative to the ground is detected by the tilt sensor 41, and the rolling angle of the rotary working machine 12 relative to the machine is detected by the stroke sensor 31. Accordingly, the rolling angle of the rotary working machine 12 with respect to the ground can be calculated from the detection values of both sensors, and the rolling cylinder 30 is driven to maintain the rolling angle of the working machine set by the tilt adjustment dial 17. A control signal is output from the controller 50 to the right-up solenoid or right-down solenoid of the electromagnetic control valve. Accordingly, the rolling cylinder 30 is expanded and contracted to change the rolling angle of the rotary working machine 12, and the detection value of the stroke sensor 31 is controlled to coincide with the target value of the horizontal control.
[0018]
Note that the pitching angular velocity sensor 42 and the rolling angular velocity sensor 43 are each of the vibration gyro type, and the structure is simple, precise, and inexpensive. However, a sensor other than the vibration gyro system may be used. The tilt sensor 41, the pitching angular velocity sensor 42, and the rolling angular velocity sensor 43 are provided at a substantially central portion near the rear axle 19 and closer to the center of gravity of the airframe than when installed on the front wheel 38 side. As a result, there is little vibration in the vertical direction and it is difficult to receive disturbances, and the measurement accuracy is improved. In addition, since all the three sensors are integrally stored in the case 44, the installation space becomes compact and the installation work can be simplified, for example, the power supply circuit can be shared.
[0019]
Further, a horizontal mode, a machine parallel mode, and an angle setting mode can be selected by the horizontal switch 45, and the horizontal switch 45 detects the relative inclination of the machine and the work machine and the inclination with respect to the ground. A target value for horizontal control is determined according to the set mode, and the rolling cylinder 30 is driven to adjust the inclination of the rotary working machine 12.
[0020]
For example, when the horizontal selector switch 45 is set to the horizontal mode, the inclination of the rotary work machine 12 with respect to the ground is calculated from the detection value of the inclination sensor 41 and the detection value of the stroke sensor 31, and this inclination is made zero. Set the target value for horizontal control. Then, a control signal is output from the controller 50 to the right-up solenoid or the right-down solenoid of the electromagnetic control valve that drives the rolling cylinder 30 so that the measured value of the stroke sensor 31 matches the target value. Therefore, control is performed so that the horizontal inclination of the rotary working machine 12 is horizontal regardless of the attitude of the machine body.
[0021]
On the other hand, when the horizontal changeover switch 45 is set to the aircraft parallel mode, the target value of the horizontal control is determined so that the lift amounts of the left and right lower links 21 are equal. Then, in order to drive the rolling cylinder 30 so that the measured value of the stroke sensor 31 coincides with this target value, a control signal is output from the controller 50 to the right raising solenoid or the right lowering solenoid. Therefore, the rotary working machine 12 is controlled so that the horizontal tilt is parallel to the tilt of the machine.
[0022]
When the horizontal changeover switch 45 is set to the angle setting mode, a target value for horizontal control is determined according to the set value of the tilt adjustment dial 17 arbitrarily set by the operator, and the measured value of the stroke sensor 31 is set to this value. In order to drive the rolling cylinder 30 so as to match the target value, a control signal is output from the controller 50 to the right-up solenoid or right-down solenoid. Therefore, the rotary working machine 12 is controlled to have an arbitrary inclination set.
[0023]
Here, noise caused by various vibrations is generated in the detection signal of the rolling angular velocity sensor 43 depending on the traveling condition and the field condition such as the traveling speed of the machine body, the hardness of the field, or the lug pattern of the tire. For example, as shown in FIG. 4, when the output signal of the rolling angular velocity sensor 43 changes from 0V to a maximum of 5V, the change in angular velocity when the aircraft rolls to the right appears upward in the graph, and the aircraft moves to the left. Assuming that the change in the angular velocity when rolling appears downward, the detection signal of the rolling angular velocity sensor 43 continuously appears in small increments due to vibration noise. Therefore, when performing horizontal control based on the rolling angular velocity, it is necessary to obtain the neutral position of the rolling angular velocity sensor 43.
[0024]
FIG. 5 shows a flowchart of the horizontal control of the present invention. When the horizontal control is started, first, the state of various sensors, switches, dials and the like are read into the controller 50 (Step 100), and then the peak value of the rolling angular velocity sensor 43 is collected (Step 110). Now, when vibration noise as shown in FIG. 4 is generated, the peak value of the angular velocity in the right direction (upper peak value) and the peak value of the left angular velocity (lower peak value) are continuously measured for a predetermined time, The moving average value of each peak value is calculated. Then, the neutral position of the rolling angular velocity sensor 43 is set from the moving average value of the rightward angular velocity peak value and the moving average value of the leftward angular velocity peak value (Step 120).
[0025]
When the specified value ω ₀ is determined in advance for the neutral position and the detected value of the rolling angular velocity sensor 43 is within the specified value ω ₀ (Step 130), the inclination sensor is regarded as detecting angular velocity due to vibration noise. The rolling angle of the airframe is calculated based on the detected value of 41, and a “right-up” or “right-down” horizontal control signal is output to the electromagnetic control valve for the rolling cylinder 30 based on the detection value of the tilt sensor 41 ( Step140). On the other hand, when a rolling angular velocity greater than the predetermined value ω ₀ determined in advance is detected, a horizontal control signal is output to the electromagnetic control valve for the rolling cylinder 30 based on the detection value of the rolling angular velocity sensor 43 ( Step 150).
[0026]
If the rolling angular velocity of the aircraft detected by the rolling angular velocity sensor 43 is ω and the detection time is T, the rolling angle θ of the aircraft is expressed by the following equation.
[0027]
θ = ω × T
The rolling angle of the rotary working machine 12 is calculated from the rolling angle θ of the machine body obtained by the above equation and the detected value of the stroke sensor 31, and the electromagnetic control valve for the rolling cylinder is operated according to the set value of the tilt adjustment dial 17. Outputs horizontal control signal.
[0028]
Here, when the neutral position of the rolling angular velocity sensor 43 is set in response to the noise described above, the vibration of the fuselage changes depending on the level of the traveling speed of the fuselage, so that the rolling angular velocity depends on the detection value of the vehicle speed sensor 40. It is necessary to correct the specified value ω ₀ . FIG. 6A shows a detection signal of the rolling angular velocity sensor 43 when the traveling speed of the airframe is low, and noise due to vibration of the airframe is relatively small. At this time, the specified value ω ₀ is set to be small with respect to the neutral position (for example, ± 0.5 V), and when a rolling angular velocity greater than the specified value ω ₀ is detected (time t ₁ ), based on this rolling angular velocity Output a horizontal control signal.
[0029]
On the other hand, FIG. 5B shows a detection signal of the rolling angular velocity sensor 43 when the traveling speed of the aircraft is high, and noise due to vibration of the aircraft is large. If so, by setting the specified value ω ₀ larger than the neutral position (for example, ± 1 V), when a larger rolling angular velocity is detected compared to when driving at low speed (time t ₂ ), Since a horizontal control signal based on the rolling angular velocity is output, malfunction due to noise can be prevented. That is, in Step 160 of FIG. 5, when it is determined from the detection value of the vehicle speed sensor 40 that the traveling speed of the aircraft is high, the specified value ω ₀ is set to be large (Step 170). Alternatively, when the traveling speed of the aircraft increases, a horizontal control signal based on the rolling angular velocity sensor 43 may be output when an angular velocity equal to or higher than the vibration noise peak value + α shown in FIG. 4 is detected. .
[0030]
Thus, when the inclination change is small, horizontal control is performed by the inclination sensor 41 as before, and when the inclination change becomes large and the rolling angular velocity becomes larger than the specified value ω ₀ , the response delay and the influence of the opposite output are affected. Ignoring the large tilt sensor 41, the rolling angular velocity sensor 43 performs horizontal control, and further, the magnitude of the prescribed value ω ₀ is corrected according to the level of the traveling speed of the aircraft, so that the accuracy of the horizontal control is improved. be able to.
[0031]
Here, the stop timing of the horizontal control signal based on the rolling angular velocity sensor 43 is slow to stop when the detected value of the angular velocity returns to the neutral position, and there is a possibility that the work implement will go too far. For this reason, when the detected value of the rolling angular velocity sensor 43 turns in the decreasing direction, for example, in FIG. 6A, the output of the horizontal control signal is stopped when the upper limit peak of the angular velocity is passed in the middle of the time t _1. To do. Thus, it is possible to prevent the working machine from overshooting due to a response delay of the hydraulic equipment.
[0032]
However, as shown in FIG. 7, after the detected value of the rolling angular velocity sensor 43 turns in the decreasing direction (period t ₃ ), the rolling angular velocity may increase again. When there is a change in the angular velocity with a period t ₃ shorter than the period width t ₀ until the value, the horizontal control signal is not stopped, and after the period width t ₀ between the noise peak values is continued, the change is continued. when turned in the decreasing direction (time t ₄ after elapse), it shall stop the horizontal control signal.
[0033]
Further, when performing horizontal control using the detection value of the rolling angular velocity sensor 43, as shown in FIG. 8, the intermediate value M1 between the upper peak value U1 and the lower peak value D1, and the upper peak value U2 and the lower peak value D1. Like the intermediate value M2, the intermediate values M1, M2, M3, M4, M5... Between the upper and lower peak values are used as the detected values of the rolling angular velocity, so that noise components caused by engine vibration and tire lag can be reduced. .
[0034]
Further, when outputting a horizontal control signal based on the detection value of the rolling angular velocity sensor 43, a change rate of the detected rolling angular velocity is calculated, and an output pulse width for the electromagnetic control valve for the rolling cylinder is calculated according to the magnitude of the change rate. Adjust. For example, when the rate of change of the rolling angular velocity is small, it is a state in which the change in the inclination of the fuselage occurs relatively slowly. Therefore, the output pulse width of the horizontal control signal is narrowed to reduce the operating speed of the rolling cylinder 30. By doing so, it is possible to prevent the work machine from going too far. On the other hand, when the rate of change of the rolling angular velocity is large, there is an abrupt change in the aircraft, and the speed is increased by widening the output pulse width of the horizontal control signal or by continuously outputting it. Thus, the tilt of the work implement can be quickly corrected by driving the rolling cylinder 30.
[0035]
On the other hand, during the horizontal control based on the detection value of the rolling angular velocity sensor 43, the work machine may be detached while the machine body is stopped or traveled at a low speed. If this is the case, the machine may vibrate, such as shaking the work machine to align the joints. If the rolling angular velocity sensor 43 detects the rolling angular velocity of the machine and outputs a horizontal control signal due to this vibration, The work machine suddenly starts moving regardless of the operator's intention, which is dangerous.
[0036]
For this reason, as shown in FIG. 9, during the horizontal control based on the detection value of the rolling angular velocity sensor 43, when the detection value of the vehicle speed sensor 40 becomes a predetermined value or less (Step 200), the aircraft stops or travels at a slow speed. Therefore, the output of the horizontal control signal based on the rolling angular velocity is prohibited (Step 210). Thus, unnecessary horizontal control output is not performed when the machine is stopped, and the danger that the work machine operates unexpectedly can be prevented. In Step 210, the horizontal control signal may not be prohibited, but the dead zone of the rolling angular velocity sensor 43 may be widened to control the output timing of the horizontal control signal.
[0037]
Thus, the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.
[0038]
【The invention's effect】
As described in detail in the above embodiment, the present invention performs the horizontal control of the work implement based on the detected value of the tilt sensor of the fuselage and the detected value of the rolling angular velocity of the fuselage.
The neutral position of the rolling angular velocity detection means is set from the average value of the peak value of the rolling angular velocity in the right direction measured by the rolling angular velocity detection means and the peak value of the rolling angular velocity in the left direction. When a rolling angular velocity larger than a predetermined value with respect to the neutral position is detected, a horizontal control signal is output based on the detected value of the rolling angular velocity, and further according to the level of the traveling speed of the aircraft. To correct the size of the specified value.
[0039]
Therefore, it is possible to accurately output a horizontal control signal based on the rolling angular velocity against vibration noise that changes according to the traveling speed of the aircraft, and unnecessary output without using a special high-performance sensor or actuator. Therefore, it is possible to perform accurate horizontal control without overshooting of the work machine and response delay at a low cost.
[0040]
Further, the present invention is configured not to output a horizontal control signal based on the detection value of the rolling angular velocity detection means when the traveling speed of the aircraft is below a certain value , so that the aircraft is stopped or traveling at a slow speed. In the state, the output of the horizontal control signal based on the rolling angular velocity is prohibited, so that the unnecessary horizontal control output is not performed when the machine is stopped, and the danger that the work machine operates unexpectedly can be avoided.
[Brief description of the drawings]
The figure shows an embodiment of the present invention.
FIG. 1 is a side view of a tractor body and a rotary work machine.
FIG. 2 is a rear view of FIG. 1 in which illustration of a rear cover sensor and the like is omitted.
FIG. 3 is a block diagram of a control system.
FIG. 4 is a graph showing a detection signal of a rolling angular velocity sensor when there is noise.
FIG. 5 is a flowchart showing a control procedure of the horizontal control device.
FIG. 6A is a graph showing detection signals and specified values of a rolling angular velocity sensor when the traveling speed of the aircraft is low.
(B) is a graph showing detection signals and specified values of the rolling angular velocity sensor when the traveling speed of the aircraft is high.
FIG. 7 is a graph illustrating timing for stopping output of a horizontal control signal.
FIG. 8 is an explanatory diagram showing an intermediate value between the upper peak value and the lower peak value of the rolling angular velocity.
FIG. 9 is a flowchart illustrating horizontal control when the traveling speed of the aircraft is equal to or less than a certain value.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Tractor 12 Rotary working machine 17 Tilt adjustment dial 30 Rolling cylinder 31 Stroke sensor 40 Vehicle speed sensor 41 Tilt sensor 43 Rolling angular velocity sensor 50 Controller

Claims (1)

A work machine is connected to the rear part of the machine body via a link mechanism, and an actuator for changing the rolling angle of the work machine relative to the machine body and a means for detecting the rolling angle of the work machine relative to the machine body are provided between the machine body and the work machine. , a horizontal control device including a tilt sensor for detecting a rolling angle of the aircraft to該機body, and a tilt setting unit for setting a rolling angle of the working machine, the rolling angular velocity detection means when the aircraft rolling in該機body And a means for detecting the traveling speed of the airframe, the peak value of the rightward angular velocity and the peak value of the leftward angular velocity are continuously measured by the rolling angular velocity detection means for a predetermined time, and the average value of each peak value is When the neutral position of the rolling angular velocity detecting means is set and a rolling angular velocity larger than a predetermined value with respect to the neutral position is detected, the rolling angular velocity is detected. A horizontal control signal of the work implement is output based on the detection value of the angular velocity detection means, and when the detection value of the rolling angular velocity detection means is within the specified value, the horizontal control signal of the work implement is determined based on the detection value of the tilt sensor. In a horizontal control device configured to correct the size of the specified value according to the height of the traveling speed of the aircraft ,
When the traveling speed of the airframe is below a certain value, a horizontal control signal based on a detection value of the rolling angular speed detection means is not output.
Horizontal control device.

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