JP3747517B2 - Control device for work vehicle - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a control device for a work vehicle such as an agricultural machine.
[0002]
[Prior art]
Agricultural machines such as tractors, combine harvesters, and rice transplanters are equipped with various control devices for work in order to efficiently perform farm work. For example, a tractor is equipped with a plowing depth control to keep the plowing depth constant during plowing work, a horizontal control device to keep the car body level on sloping ground, or a speed control device to control the traveling speed of the car. Yes.
[0003]
In such an agricultural machine control device, the central control unit receives signals from various sensors or various drive units, and centrally controls an output device such as an electromagnetic valve of a transmission constituting the agricultural machine. Yes. For this reason, when a change was made to the electromagnetic valve, various sensors, etc., the central control unit had to be changed. The central control unit had to be adapted to the type and model of the agricultural machine, and labor was required to manage the control unit. In recent years, communication control processing has advanced, and by providing a communication-dedicated IC, it has become possible to perform control while communicating at high speed as if a plurality of control units function as an integrated control unit. For this reason, the control unit is divided into functions according to each control target such as an output device to make a terminal control unit, and these are connected to the central control unit by communication, and by combining according to the model and model, the model The control unit can be shared regardless of the model.
[0004]
[Problems to be solved by the invention]
For example, the agricultural machine control device in which the central control unit and the terminal control unit are each provided with a dedicated IC for communication control, when the communication control IC is damaged during control and communication is disabled. If the output circuit holds the current output state, the terminal control unit cannot receive the control signal from the central control unit, and the output device such as a valve that operates in the terminal control unit falls out of control. There is a risk.
[0005]
An object of the present invention is to provide a control device for an agricultural machine that improves the safety by turning off the output of the output device when output communication from the central control unit is interrupted for a certain time or more.
[0006]
[Means for Solving the Problems]
The above object of the present invention is achieved by the following configuration.
That is, the central control unit (51) and a plurality of terminal control units (52, 53 ) each connected by a wired communication means controlled by a control signal output from the central control unit (51) and provided with a CPU. a control apparatus for a work vehicle provided with a respective terminal control unit (52, 53) share a power circuit (71), from the previous SL power supply circuit (71) to all of the terminal control unit (52, 53) An emergency output stopping means (73 ) capable of turning on and off the input, and an abnormality determining means for turning off the emergency output stopping means (73 ) and stopping the output of signals from the terminal control section (52, 53 ) to the outside. (69, 70), and when there is no communication for a predetermined time or more between the central control unit (51) and the terminal control unit (52, 53), the abnormality determining means (69, 70) Determine the emergency output stop It is a control device for a work vehicle characterized in that the stage (73) is turned off to turn off the output from the power supply circuit (71) to all the terminal control units (52, 53) .
[0007]
The communication circuit of the present invention refers to (1) a communication function circuit or (2) a communication control circuit or a communication line.
[0008]
The agricultural machine control device of the present invention has a communication circuit in the central control unit (51) and a plurality of terminal control units (52, 53 ) distributed in the output device of each part of the machine body. The terminal control units (52, 53 ) and the central control unit (51) can communicate with each other by connecting the detection signals from the sensors and the output signals to the valves with wired communication means.
[0009]
The agricultural machine controller of the present invention, the communication line with on-off means in the emergency which can turns on and off the input from the power supply circuit (71) to the terminal control unit of the whole hand (52, 53) (73) Since it is provided, the output signal of each terminal control section (52, 53 ) can be stopped immediately. Of the terminal control units (52, 53 ) , those that are output to the outside, such as valve outputs, are determined to be abnormal when there is no communication for a certain period of time, and the output is stopped, and the terminal control unit for external output Since the abnormality judging means (69, 70) for turning off the output of (52, 53 ) is provided, the safety is high.
The control device (control circuit 90) of the present invention can be applied to tractors, combines, rice transplanters, and the like.
[0010]
Embodiment
The control device of the present invention is provided in, for example, an agricultural tractor (hereinafter referred to as a tractor). Therefore, a tractor control device will be described below. The tractor shown in FIG. 1 is provided with a control device including a central control unit and a terminal control unit as shown in FIG.
[0011]
First, the tractor will be described with reference to FIGS. 1, 2, and 3.
The traveling vehicle body 2 of the tractor 1 is provided with a pair of left and right front wheels and a pair of left and right rear wheels on the front and rear, and the rotational power of the engine 4 covered with the bonnet 3 is appropriately decelerated by the transmission of the transmission case 5 and the pair of front wheels 7 , 7 and the rear wheels 8, 8 respectively.
[0012]
Further, a driver's seat 9 is provided above the mission case 5, and a position operation lever 11 (see FIG. 2) for adjusting the height position of the work implement 29 protrudes on the side of the driver's seat 9. In addition, a horizontal control changeover switch 13, a decelera position setting device 14, a transmission lever 15 and the like are installed. A cylinder case 17 containing a single-acting hydraulic cylinder 16 is provided at the upper part of the mission case 5, and a vehicle body level sensor 18 is installed. The hydraulic cylinder 16 is configured to rotate a pair of lift arms 21 and 21 that are pivotally supported on the left and right sides of the hydraulic cylinder case 17.
[0013]
Further, a three-point link mechanism comprising a top link 22 and lower links 23 and 23 is provided at the rear part of the traveling vehicle body 2 and is connected to lift arms 21 and 21 and lower links 23 and 23 by lift rods 25 and 26, respectively. The lift rod 25 is extendable and retractable by a hydraulic cylinder. The lift rod 25 is provided with a stroke sensor 27 in parallel with the rod 25 (see FIG. 3).
[0014]
The work machine 29 is equipped via the three-point link mechanism and performs ground work while being pulled by the traveling vehicle body 2. The working machine 29 includes a tilling portion 31 and a cover portion 32 surrounding the tilling portion 31. In the tillage unit 31, the rotational power of the engine 4 is transmitted from the rear PTO shaft 33 of the traveling vehicle body 2 to the rotation shaft 35 via the transmission shaft and the transmission mechanism of the work implement 29, and a plurality of rotations attached to the rotation shaft 35. The claw 36 is driven and rotated to pulverize, agitate, and plow the soil in the field. The cover portion 32 includes a rotary cover 38 above the rotation shaft 35 and a rear cover 39 pivotally attached to the rear portion of the rotary cover 38. Further, a tilling depth sensor 42 that detects the rotation angle of the rear cover 39 is provided on the upper surface of the rear end of the rotary cover 38.
[0015]
As an example of the control device of the present embodiment, the working depth control device for keeping the work implement 29 at the plowing depth value of the field, and the horizontal control device for controlling the horizontal tilt so that the plowing depth in the left-right direction is the same. Is provided. Furthermore, a position control device is also provided for the operator to raise and lower the work machine 29 to an arbitrary height. Independent of this position control device, the work machine 29 is moved up and down by a lift switch 44 (see FIG. 2). A device that forcibly moves up and down to a set height and an installed state by operation is also provided.
[0016]
For example, plowing depth control will be described. A plowing depth setting value is set by a plowing depth setting device 12 provided on the side of the driver's seat 9. The hydraulic cylinder 16 is operated so that the work implement 29 is controlled to move up and down so that the plowing depth detection value of the plowing depth sensor 42 matches the plowing depth setting value. When the rear cover 39 moves up and down due to unevenness in the field during work, the change is detected by the tilling depth sensor 42 and transmitted to the controller. The controller operates the hydraulic cylinder 16 to return the working depth to the working depth setting value, and raises and lowers the work implement 29.
[0017]
FIG. 4 shows a part of the control device of the present embodiment. The central control unit 51, the terminal control unit (for example, the horizontal control unit) 52 of the work machine 29 that is a part of the terminal control unit, and the terminal control of the traveling vehicle body 2. The block diagram of the control apparatus with the part (for example, transmission control part) 53 is shown.
[0018]
Explaining the horizontal control, the mode can be selected by the horizontal control change-over switch 13 (see FIG. 2) on the side of the driver seat 9. The horizontal control changeover switch 13 has a “horizontal” mode, a “body parallel” mode, and a “manual” mode. The “horizontal” mode is a mode in which the work implement 29 is controlled to be kept horizontal, and the “vehicle body parallel” mode is a mode in which the left and right inclinations of the traveling vehicle body 2 and the work implement 29 are kept in parallel. The “manual” mode is control for making the working machine tilt to an arbitrary tilt.
[0019]
When the tractor 1 tilts left and right due to the unevenness of the field during the operation, the horizontal sensor 54 detects the tilt of the field, and the analog signal output value detected by the horizontal sensor 54 is converted into a digital signal by the A / D converter in the CPU 57. The value is transmitted to the central control unit 51 via the communication circuit 58. Here, the CPU 61 of the central control unit 51 calculates the tilt angle with respect to the work implement 29 and the traveling vehicle body by taking into account data such as various setting modes of the tractor 1. At this time, as in the case of the horizontal sensor 54, the length of the hydraulic cylinder 16 is detected by the stroke sensor 55, which is converted into a digital signal and transmitted to the central control unit 51 via the communication circuit 58. . Accordingly, the expansion / contraction of the hydraulic cylinder 16 is determined, and the valve output signal is sent to the terminal control unit (horizontal control unit) 52 via the communication circuit 58. The CPU 57 controls the electromagnetic valve based on this signal to extend and contract the hydraulic cylinder 16. During this time, the CPU 61 sequentially receives the detection value of the stroke sensor 55 from the communication circuit and performs control. When the stroke sensor 55 reaches the target length, the valve stop signal is similarly sent to the terminal control unit (horizontal control unit) 52 to stop the valve.
[0020]
Further, the terminal control unit (shift control unit) 53 operates the electromagnetic valves 66 and 67 of the transmission to select an appropriate shift step of the traveling device for the shift step detected by the shift position sensor 65.
[0021]
In the control apparatus of this embodiment shown in FIG. 4, a communication circuit having a hardware configuration is incorporated in each of the central control unit 51 and each of the terminal control units 52, 53. Therefore, when a new control technology is adopted in any one of the terminal control units 52, 53,..., The software of the corresponding terminal control unit 52, 53. Just change it.
[0022]
Each terminal control unit 52, 53... Is provided with a watchdog timer 69, 70..., And each terminal control unit 52, 53. Further, the terminal control units 52, 53... Have emergency stop switches 73, 74.
[0023]
Therefore, among the terminal control units 52, 53..., Output to the outside such as the operation of the work machine 29 or selection of the transmission gear stage by the output of the electromagnetic valves 62, 63. The watchdog timers 69, 70, etc. are monitored and when there is no communication for a certain period of time, it is judged as abnormal and the emergency stop switches 73, 74,. . Here, the emergency stop switch 73 stops the control of the terminal by turning off the power line of the control unit, and the emergency stop switch 74 has a dedicated signal line for stopping.
[0024]
At this time, if the output is stopped by communication, there is a possibility that a time delay occurs until the stop signal is received, and there is a possibility that it will not be in time for the emergency, but the control device shown in FIG. Since the power supply circuit 71 is shared, the common power supply circuit 71 of the terminal control units 52, 53... Can be turned on / off by the emergency stop switch 73. By turning it off, the output unit can be stopped without time delay. Further, when the emergency stop switch 73 of this embodiment is used, an emergency stop can be performed regardless of the congestion of the communication line. Furthermore, the power supply circuit 71 can be shared to reduce the cost.
[0025]
Further, as generalized in FIG. 5 and showing the control device of this embodiment, the input control units 81, 82..., The central control unit 51, and the terminal control units 52. When the communication circuits 91, 92,..., 60, 58, and so on are incorporated respectively, and the watchdog timer 69 is provided in the terminal control unit 52. Can be determined to be abnormal, and a method of stopping output by transmitting a reset signal of the terminal control unit 52... To each of the output drivers 101.
[0026]
In the case of the configuration shown in FIG. 5, the layout of the terminal controller is divided into an output system terminal control unit 52... And an input system block 81, 82. .. is attached only to the terminal control unit 52 of the output system, and the control units 81, 82,... Of the input system are configured to operate even if there is a communication abnormality, so that failure diagnosis in the event of an abnormality Is easy to configure. The control units 81, 82... Of the input system are input independently of the central control unit 51 or the terminal control unit 52... By the communication circuits 91, 92. Since the system can be controlled, the control units 81, 82... Of the input system and the central control unit 51 can be kept operating. In this case, the control units 81, 82 of the input system are operated. .. And the central control unit 51 can check the cause of failure by a tester or the like.
[0027]
Similarly, a configuration in which the common power source of the terminal control unit as shown in FIG. 4 can be turned ON / OFF only to the output terminal of the emergency stop switch as shown in FIG.
[0028]
Further, as shown in FIG. 6, the input control units 81, 82..., The central control unit 51, and the terminal control units 52. 102..., And the terminal control unit 52... That outputs to the outside such as a valve output is a manual input switch to the output driver 111. If 121 is connected, it can be output manually even if the communication circuit 102 is disconnected. In this case, there is an advantage that it can be manually operated when the communication circuit 102...
[0029]
7 is an agricultural control controller that controls a plurality of controllers 131, 132,... Using a communication circuit 141, 142,..., And performs emergency communication separately from the communication lines 151 of each controller. A line 152 may be provided, and an emergency stop switch 161 may be provided on the line 152 so that the output signals of the controllers 131, 132,... Can be stopped immediately.
[0030]
In this case, in an agricultural machine that performs a plurality of controls using a plurality of controllers 131, 132,... Together with a plurality of sensors, etc., communication circuits 141, 142,.・ Agricultural work can be carried out with good accuracy while taking steps for each control using, but in case of an emergency, the communication stop 151 is communicated to each controller 131, 132. Causes a time lag, an emergency stop switch line 152 common to the controllers 131, 132,... Is provided in addition to the communication lines 151, so that output of all the controllers 131, 132,. It is a thing.
[0031]
As shown in FIG. 8, the emergency stop input terminals 181, 182,... Are provided in the CPUs 171, 172,. May be connected. In this case, after the emergency stop is canceled while monitoring the controllers 131, 132,..., The automatic control of the controllers 131, 132,.
[0032]
Further, as shown in the flowchart of FIG. 9, it is dangerous that the control of each output device starts immediately after the emergency stop is canceled, so that the controller 131, 132. (See FIG. 8). Measures that can be detected are taken, and after the emergency stop is released, the control can be safely switched to a predetermined control. For example, when an emergency stop of the shift speed is made, the shift speed is set to neutral so that it can be restarted safely.
[0033]
In the example shown in FIG. 9, when the key switch is turned on, the control is not started even if the automatic switch 195 (see FIG. 8) is turned on. Automatic control will not start until it is turned off. Further, even if the emergency stop switch 161 (see FIG. 8) is turned off, the automatic control does not work immediately, and the automatic switch 195 is turned off and then the control is started.
[Brief description of the drawings]
FIG. 1 is a side view of a tractor according to an embodiment of the present invention.
FIG. 2 is a plan view of the vicinity of the driver seat of the tractor of FIG.
3 is an inclined view of a three-point link mechanism portion of the tractor of FIG. 1. FIG.
FIG. 4 is a block diagram of a control device according to an embodiment of the present invention.
FIG. 5 is a block diagram of a control device according to an embodiment of the present invention.
FIG. 6 is a block diagram of a control device according to an embodiment of the present invention.
FIG. 7 is a block diagram of a control device according to an embodiment of the present invention.
FIG. 8 is a block diagram of a control device according to an embodiment of the present invention.
FIG. 9 is a control flowchart of each output device after cancellation of an emergency stop according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tractor 2 Traveling vehicle body 3 Bonnet 4 Engine 5 Transmission case 7 Front wheel 8 Rear wheel 9 Driver's seat 11 Position control lever 12 Plowing depth setting device 13 Horizontal control changeover switch 14 Decera position setting device 15 Shift lever 16 Hydraulic cylinder 17 Cylinder case 18 Car body Horizontal sensor 21 Lift arm 22 Top link 23 Lower link 25, 26 Lift rod 27 Stroke sensor 29 Working machine 31 Tilling part 32 Cover part 33 Rear PTO shaft 35 Rotating shaft 36 Rotating claw 38 Rotary cover 39 Rear cover 42 Plowing depth sensor 44 Lift switch 51 Central Control Units 52 and 53 Terminal Control Unit 54 Car Body Horizontal Sensor 55 Stroke Sensor 57 Central Control Unit CPU
58, 60, 91, 92, 102, 141, 142 Communication circuit 61 Terminal control unit CPU
62, 64 Electromagnetic valve for horizontal control 65 Shift position sensor 66, 67 Electromagnetic valve for transmission 69, 70 Watchdog timer 71 Power supply circuit 73, 74 Emergency stop switch 81, 82 Input control unit 101 Output driver 111 Output driver 121 Manual input Switches 131 and 132 Controller 151 Communication line 152 Emergency communication line 161 Emergency stop switch 171 and 172 Controller CPU
181 and 182 Emergency stop input terminal 191 and 192 Emergency stop line 195 Automatic switch

Claims (1)

In a control device for a work vehicle, which is connected with a central control unit and wired communication means controlled by a control signal output from the central control unit, and includes a plurality of terminal control units each provided with a CPU.
Each terminal control unit shares the power supply circuit,
And output stop means emergency that can switching on and off the input to all of the terminal control unit before Symbol supply circuit,
An abnormality determining means for turning off the emergency output stopping means and stopping the output of the signal from the terminal control unit to the outside ; and
When there is no communication for a certain time or more between the central control unit and the terminal control unit, it is determined that the abnormality is determined to be abnormal by the abnormality determination unit, and the emergency output stop unit is turned off to all terminal control units. An output from the power supply circuit is turned off .

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