KR100453266B1 - Sensor calibration device for working vehicle - Google Patents

Abstract

The present invention provides a sensor zero correction device for a work machine, comprising: an actuator for connecting a ground work device to a rolling free-rolling driving body, and rolling the ground work device with respect to the traveling gas, and the left and right inclination angles of the traveling gas or the ground working device. An inclination sensor for detecting a degree and an angular velocity sensor for detecting an angular velocity in the left and right inclination directions of the traveling body or the earth work device, and based on the detected values of both the inclination sensor and the angular velocity sensor, A sensor zero correction device for a work machine provided with a rolling control means for operating the actuator such that the left and right postures of the ground work device are maintained at a set angle, the average value being calculated based on a sampling output value detected by the angular velocity sensor. Average calculation processing means and the average value obtained by this average calculation processing means is zero. And a zero point control means for making a point, and a posture stability determining means for discriminating between high and low posture stability of the traveling gas, and the higher the posture stability of the traveling gas, the more the number of sampling output values used for the average calculation process. The smaller the number is set, the lower the posture stability of the traveling gas is, and the larger the number of sampling output values used for the calculation process is set.

Description

Sensor zero compensation device of work machine {SENSOR CALIBRATION DEVICE FOR WORKING VEHICLE}

The present invention relates to a sensor zero correction device for a work machine such as a tractor, a rice transplanter, and a direct wave machine. More specifically, the zero point of an angular velocity sensor that drifts due to temperature or other change in manufacturing conditions, even during operation of the work machine. It is about a technique that can be obtained accurately.

In rolling control of a ground work device in a work machine such as a tractor, by using both the inclination sensor and the angular velocity sensor as the work device or the displacement detection means of the gas, the response is good and there is no malfunction. It is known to perform precise and accurate control operations.

That is, as disclosed in Japanese Patent Laid-Open No. 2-216412, an inclination sensor (low speed reaction sensor), a light gyro, etc. made of a weight, a potentiometer for detecting the swing amount of the weight, and the like The rolling control device is configured by using both of the angular velocity sensors (high speed response sensor). Thus, a damper or filter is provided by combining an angular velocity sensor that is not affected by inertia and excellent response, and an inclination sensor that compensates for the shortcomings of the angular velocity sensor whose absolute inclination angle cannot be detected at the time of detection. Without this, rolling control is performed quickly and accurately, and the work accuracy of land can be improved.

In other words, by integrating the angular velocity output dθj / dt with a gyro sensor such as a vibration type, it is possible to obtain an inclination angle change θj which is not affected by the lateral fluctuation of the sensor case body. However, since the gyro sensor can detect only the change in angle, an inclination sensor is required for detecting the absolute angle.

However, even in the rolling control by the above two kinds of sensors, there is still a problem to be solved. That is, the angular velocity sensor drifts easily at zero point (so-called reference voltage) due to temperature change or the like, so that accurate rolling control is not performed. For example, the gyro sensor outputs the angular velocity as a deviation from the reference voltage. Since the reference voltage has a solid difference or a temperature change, the angular velocity output (dθj / dt) always includes a large error, and the tilt angle change Errors are accumulated by the integrating process for obtaining the minute [theta] j, and the obtained inclination angle [theta] deviates from the actual inclination angle with time.

In order to make the reference voltage correspond to the solid difference, a process of averaging the voltage at the time of gas stop and substituting the reference voltage may be performed. In addition, if the processing is performed regularly, it is possible to cope with temperature changes. However, a work machine such as a tractor has a lot of continuous work, and thus can not secure the stop time, the above-described processing was impossible.

An object of the present invention is to precisely perform zero calibration of an angular velocity sensor drift due to temperature change, even in a work machine that is always in operation such as a tractor. Is to make it practical.

1 is a perspective view showing the structure of the rear of the agricultural tractor,

2 is a functional system diagram showing a schematic structure of rolling control;

3 is a block diagram showing the concept of tilt angle detection with a zero correction function;

4 is a graph showing output characteristic graphs of an inclination sensor and an angular velocity sensor;

5 is a graph showing output characteristic graphs of the inclination sensor and the angular velocity sensor;

6 is a functional system diagram of the rolling control to correct based on the temperature of the angular velocity sensor,

7 is a functional system diagram of the rolling control to be corrected based on the angle of rotation sensor,

8 is a functional system diagram of rolling control correcting based on the elapsed time after the main key is turned ON;

(Explanation of symbols for the main parts of the drawing)

4: Land Work Equipment 8: Actuator

15: Inclination sensor 21: Travel gas

23: angular velocity sensor 24: rolling control means

25: memory means 26: sensor zero correction means

26a: average calculation processing means 26b: low pass filter

27: vehicle speed sensor 28: inclination angle detection means

31: steering wheel 33: angle angle sensor

38: temperature sensor 39: main switch

40: time measurement means

The starting technique of the present invention is to connect an earth work device to a rolling freely moving body, and to detect an actuator for rolling the land work device with respect to the travel gas, and the left and right inclination angles of the travel gas or the earth work device. An inclination sensor and an angular velocity sensor for detecting an angular velocity in the left and right inclination directions of the traveling gas or the earth work device, and based on detection values of both the inclination sensor and the angular speed sensor. It is a sensor zero correction device for a work machine which is provided with a rolling control means for operating the actuator so that the left and right posture is maintained at a set angle.

In the above-mentioned starting technology, a first feature of the present invention for solving the above problems is an average calculation processing means for calculating an average value based on a sampling output value detected by the angular velocity sensor, and this average calculation processing means. Zero control means for setting the average value obtained by the zero to zero, and posture stability determining means for discriminating the high and low posture stability of the traveling gas, and the higher the posture stability of the traveling gas is used for the average calculation process. The number of sampling output values to be set is set smaller, and the lower the attitude stability of the traveling gas is, the larger the number of sampling output values used for arithmetic processing is set.

As described above, since a work machine such as a tractor basically travels unsteady ground, it is impossible to obtain a zero point with high accuracy by averaging the sampling output value at the time of stopping. However, although the traveling body is always rolling left and right, it does not rotate in one direction (that is, rotates horizontally) and always tilts back and forth while returning to a horizontal position. When sampling and averaging over a period sufficiently longer than the period, it has been newly found that the output values due to left and right rolling are canceled, and it is possible to obtain an accurate zero point most of the time. However, if the sampling time is too long, it is impossible to cope with the zero change, so it is not an advantageous measure to increase the number of samples unnecessarily.

Taking this into consideration, according to the above feature, the left and right inclinations are relatively calm and the inclination angle itself is small. The higher the posture stability of the traveling gas is, the smaller the number of sampling output values used for the calculation process is set. When this is gentle, it is possible to quickly find the zero point of the angular velocity sensor by averaging. In addition, since the left and right slopes are relatively significant and the inclination angle itself is large, the lower the posture stability of the traveling gas is, the larger the number of sampling output values used for arithmetic processing is. Will be.

In the above starting technology, in order to solve the above problems, a second feature of the present invention is a low pass filter for performing a low pass filter process on a sampling output value detected by the angular velocity sensor; And a zero point control means for zeroing the output value of the low pass filter, and a posture stability determining means for discriminating the high and low posture stability of the traveling gas, and the higher the posture stability of the traveling gas, the higher the cutoff of the low pass filter. The higher the frequency is set, the lower the attitude stability of the traveling gas is, the lower the cutoff frequency of the low pass filter is set.

This second feature differs from the first feature by using a low pass filter in place of the average calculation processing means for averaging the sampling output value. The average arithmetic processing means and the low pass filter may have the effect of outputting an average value of time series data. The average arithmetic processing means has the same positive component as that of the noise. There is an advantage that the noise can be cut completely, and the low pass filter has an advantage of reducing the phase delay of the output as compared with the average calculation processing means. In the sensor zero correction device as described above, the lower the posture stability of the traveling gas is, the lower the cutoff frequency of the low pass filter is, so that it is possible to reliably cope with the zero change.

As disclosed in the application claim 3, the sensor zero correction apparatus provided with both the above-mentioned first and second features is also an important proposal of the present invention. It is preferable to use the average arithmetic processing means and the low pass filter separately according to the noise component mixed in the signal component from the angular velocity sensor, or to use both at the same time.

One of the preferred embodiments of the present invention relating to the above-described posture stability determining means is a vehicle speed sensor for detecting the traveling speed of the traveling body. On the basis of the signal obtained by the vehicle speed sensor, the traveling speed is checked, and as the traveling speed becomes slower, the state that the lateral fluctuations are smaller or less likely to occur, i.e., the posture stability is high, so that the sampling output value used for the calculation process By reducing the number, it is possible to quickly find the zero point of the angular velocity sensor by averaging. As the running speed is faster, the lateral fluctuation or the like is more likely to occur, i.e., the posture stability is lowered. It becomes possible.

Another preferred embodiment of the present invention relating to the posture stability determining means is an angular velocity sensor that is originally provided. For example, the smaller the output value of the angular velocity sensor, the smaller or less prone to the lateral fluctuation, that is, the higher the posture stability. Thus, the number of sampling output values used in the calculation process is reduced, so that the angular velocity sensor It is possible to find the zero quickly. The larger the output value of the angular velocity sensor is, the more the lateral fluctuation or the like is likely to occur, i.e., the posture stability is low. It can be obtained correctly.

Another preferred embodiment of the present invention relating to posture stability determining means is an inclination sensor. For example, the smaller the output value of the inclination sensor, the smaller the lateral fluctuation or the like, which is less likely to occur, that is, the higher the posture stability. It is possible to quickly find the zero of. As the output value of the inclination sensor increases, the state that the lateral fluctuation or the like tends to be large or easy to occur, i.e., the posture stability is low. It can be obtained correctly.

Another preferred embodiment of the present invention relating to posture stability discriminating means is a tilt angle sensor for detecting a tilt angle of a steering wheel. For example, the smaller the output value of the angle-of-angle sensor, the smaller the lateral fluctuation, etc., or the more difficult it is to produce, i.e., the higher the posture stability. It is possible to quickly find the zero of. Since the larger the output value of the angle of inclination sensor, the larger the lateral fluctuation or the like is likely to occur, that is, the lower the posture stability. In this case, the number of sampling output values used in the calculation process is increased, and the angular velocity by averaging It is possible to accurately determine the zero point of the sensor.

In the above-mentioned starting technology, a third feature of the present invention for solving the above-mentioned problems is an average calculation processing means for calculating an average value based on a sampling output value detected by the angular velocity sensor, and this average calculation processing. And a zero point control means for zeroing the average value obtained by the means, and state stability discriminating means for discriminating between high and low state stability affecting a change in sensor zero, and the higher the state stability, the higher average stability processing. The number of sampling output values to be used is set to be larger, and the lower the state stability is, the smaller number of sampling output values to be used for arithmetic processing is to be set.

In this third feature, the higher the state stability associated with the running gas state affecting the variation of the sensor zero, for example, the instability of the sensor output due to the environmental temperature or the instability at the beginning of operation of the controller, the higher the calculation. Since the number of sampling output values used in the system is set to be larger and the state stability is lower, the number of sampling output values used in the calculation is set to be smaller. Therefore, when there are few zero drifts, the zero point can be accurately obtained by using many sampling output values. At the same time, when the zero drift is large, it is possible to follow the change by reducing the sampling output value.

In the above-mentioned starting technology, a fourth feature of the present invention is to provide a low pass filter for performing a low pass filter on a sampling output value detected by the angular velocity sensor, and a low pass filter. A zero control means for zeroing the output value and state stability determining means for discriminating between high and low state stability affecting the variation of sensor zero, and the higher the state stability, the lower the cutoff frequency of the low pass filter. The lower the state stability, the higher the cutoff frequency of the low pass filter. This fourth feature differs from the third feature by using a low pass filter in place of the average calculation processing means for averaging the sampling output value. Here, as the state stability is low, that is, the error component included in the output value of the angular velocity sensor becomes large, and the disturbance or disturbance increases in this measurement system, the cutoff frequency of the low pass filter is set high, so that quick zero correction is performed. .

Thus, even when the state stability discriminating means is provided, the sensor zero correction apparatus provided with both the above-mentioned third and fourth features is also an important proposal of the present invention, as disclosed in the application claim 10. . It is preferable to use the average arithmetic processing means and the low pass filter separately according to the noise component mixed in the signal component from the angular velocity sensor, or to use both at the same time.

One of the preferred embodiments of the present invention relating to the above-described state stability determining means is a temperature sensor for detecting the temperature of the angular velocity sensor. In work machines, angular velocity sensors are often placed on the sides of the engine and the transmission case, which are accompanied by temperature changes, and during continuous operation, the engine or transmission case shows a stable state that is maintained at a constant temperature. When there is light weight in the workload, it shows the unstable state that the temperature changes. This instability is a condition that greatly affects the variation of sensor zero. Therefore, it is important to change the setting of the average calculation processing means or the low pass filter based on the temperature sensor which detects the presence or absence of the temperature change of the angular velocity sensor. You can determine whether it is.

Another preferred embodiment of the present invention relating to the above-described state stability determining means is time measuring means for detecting an elapsed time from when the main switch is turned on. For example, the engine (transmission case) temperature continues to rise for a while immediately after starting the engine, and after a certain time, the engine temperature drops to a predetermined value and becomes stable. The longer it is, the larger the number of sampling output values used for the calculation. The shorter the time from the main switch ON, the smaller the number of sampling output values used for the calculation.

(Embodiment of invention)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

Fig. 1 shows a rear part of an agricultural tractor, which is an example of a work machine, and with respect to the traveling body 21 through a top link 1 and a pair of lower links 2, which are free to swing up and down, on the transmission case 3. The rolling free rotary tiller (an example of a land work device) 4 is connected. The upper part of the transmission case 3 is provided with a pair of lift arms 6 which are oscillated up and down by the hydraulic cylinder 5, and a pair of lift arms 6 and the lower link 2 are lift rods ( 7) and a double-acting hydraulic cylinder (an example of an actuator) 8. 19 is a pair of left and right driving rear wheels.

As shown in FIG. 2, the control valve 16 of the 3-position switching type with respect to the hydraulic cylinder 5 is operated by the control apparatus 22, and the rotary cylinder is operated by the hydraulic cylinder 5 and the lift arm 6. As shown in FIG. The tilling device 4 is driven up and down. The three-position control valve 17 for the hydraulic cylinder 8 is operated by the control device 22, and the rotary tiller 4 is operated by the expansion and contraction operation of the hydraulic cylinder 8, and the hydraulic cylinder 8 Is rolled around the connection point of the lower link (2) on the opposite side.

The agricultural tractor sets the height of the rotary cultivation device 4 with respect to the elevating control means 29 and the traveling gas 21 for maintaining the rotary cultivation device 4 at the set height from the ground and maintaining the cultivation depth at the set value. The control device 22 is provided with a rolling control function for maintaining the position control means 30 held at the position and the inclination angle in the left and right directions of the rotary tiller 4 with respect to the horizontal plane at the set angle.

As shown in FIG. 2 and FIG. 1, the rear tiller 9 is provided with the rotary tiller 4 freely up and down, and the rear cover 9 is pressurized downward by the spring 18, and the rotary tiller The tilling depth sensor 10 which detects the up-down swinging angle of the rear cover 9 with respect to (4) is provided, and the detection value of the tilling depth sensor 10 is input into the control apparatus 22. As shown in FIG. As a result, the lift control means 29 causes the detected value of the tilling depth sensor 10 to be the set till depth of the potentiometer-type tilling depth setter 11 in the dial operation type provided on the traveling body 21. The control valve 16 is operated, and the rotary tiller 4 is automatically lifted and driven by the hydraulic cylinder 5.

As shown in FIG. 2 and FIG. 1, the angle sensor 13 which detects the vertical angle of the lift arm 6 with respect to the traveling body 21 is provided in the base of the lift arm 6, and the angle sensor The detection value of (13) is input into the control apparatus 22. As shown in FIG. Thereby, the position control means 30 operates the control valve 16 so that the detection value of the angle sensor 13 may become the target value of the lever operation type position setter 12 provided in the traveling body 21. The lift arm 6 oscillates up and down by the hydraulic cylinder 5.

In the above-described lifting control means 29 and the position control means 30, the detected value of the angle sensor 13 corresponding to the set tilling depth of the tilling depth setter 11 and the target value of the position setter 12. Is compared, and when the target value of the position setter 12 is higher, the lift control means 29 and the rolling control function described later stop (the hydraulic cylinder 8 is stopped), and the position control means 30 ) Works. Thereby, the control valve 16 is operated so that the detection value of the angle sensor 13 may match with the target value of the position setter 12, and the rotary tiller 4 is driven up and down by the hydraulic cylinder 5. As shown in FIG. . Therefore, by operating the position setter 12, the rotary tiller 4 is moved to the traveling body 21 in a range higher than the detected value of the angle sensor 13 corresponding to the set tilling depth of the tilling depth setter 11. Can be driven up and down at any height and stopped.

Next, when the position setter 12 is operated to the downward side and the target value of the position setter 12 matches the detected value of the angle sensor 13 corresponding to the set tillage depth of the tillage depth setter 11 ( Or lower), the position control means 30 stops, and the lift control means 29 and the rolling control function operate. As a result, the control valve 16 is operated so that the detected value of the tillage depth sensor 10 is set by the lift control means to be the set tillage depth of the tillage depth setter 11, and the rotary cylinder is operated by the hydraulic cylinder 5. The device 4 is automatically lifted and lowered. As described later, the control valve is operated so that the inclination angle of the rotary tiller 4 with respect to the horizontal plane is maintained at a set angle inclined to the horizontal plane (or parallel to the horizontal plane) by the rolling control function. (17) is operated and the rotary tiller 4 is rolled-driven by the hydraulic cylinder 8. As shown in FIG.

As shown in Figs. 1 and 2, in this agricultural tractor, the angle of inclination of the rotary tiller 4 with respect to the horizontal plane is set at an angle of inclination (or parallel with the horizontal plane) to the horizontal plane. It is provided with rolling control means 24 which roll-drives the rotary cultivation apparatus 4 so that it may be hold | maintained. And a dial-type inclination setter 20 for setting the set angle in the left and right directions of the rotary tiller 4, which sets and sets the set angle arbitrarily and continuously from the horizontal position to the lower right side and the lower left side. It is configured to change.

That is, the central inclination sensor 15 for detecting the left and right inclination angles of the traveling body 21, the angular velocity sensor 23 of the oscillating gyro type for detecting the angular velocity in the left and right inclination directions of the traveling body 21, and the hydraulic pressure. A stroke sensor 14 for detecting the operating position of the cylinder 8 is provided, and the left and right tilt angles of the rotary tiller 4 with respect to the base body 21 can be detected by the operating position of the rolling cylinder 8. Therefore, on the basis of the detected values of both the inclination sensor 15 and the angular velocity sensor 23, the hydraulic cylinder 8 is maintained such that the left and right postures of the rotary tiller 4 are maintained at the set angle by the inclination setter 20. The rolling control means 24 for activating) is provided in the control device 22.

Then, as a core element of the inclination angle detecting means 28, the sensor zero correction means 26 for updating and correcting the reference voltage of the angular velocity sensor 23 drifted by the manufacturing conditions such as temperature over time. This hardware or software, or both, is built into the control device 22. The sensor zero correction means 28 includes a storage means 25 for storing a plurality of sampling output values detected by the angular velocity sensor 23 and an average value calculated on the basis of the stored plurality of sampling output values. It includes a zero point control means 26 and a discrimination circuit 41 to be zero. For this reason, the zero point control means 26 includes an average calculation processing means 26a that calculates the average value based on the sampling output value.

Furthermore, as shown in FIG. 2, the rotation speed of the transmission shaft 32 to the rear wheel 19 (refer FIG. 1) and the front wheel 31 is detected, and the traveling speed of the traveling body 21 is detected. The vehicle speed sensor 27 is provided, and the attitude | position stability discrimination means is comprised by this vehicle speed sensor 27 and the discrimination circuit 41 which processes this detection information. That is, the higher the traveling speed, the lower the posture stability of the traveling body 21, and the lower the traveling speed, the higher the posture stability of the traveling body 21 is determined.

The sensor zero correction means 28 is used for arithmetic processing as the posture stability of the traveling body 21 is higher, based on a signal from the posture stability determining means for discriminating the high and low posture stability of the traveling body 21. The number of sampling output values is set to be small, and the lower the attitude stability of the traveling body 21, the more the number of sampling output values to be used for arithmetic processing is set.

3, a block diagram of the inclination angle detecting means 28 using the inclination sensor 15 and the angular velocity sensor 23 is shown. In Fig. 3, the first error correction G1 functioning as the sensor zero correction device 26 performs constant interval averaging processing and adaptive LPF (low pass filter) processing to completely remove noise generated within the average interval. Do it. The constant interval average processing is performed by the average calculation processing means 26a, and the adaptive LPF (low pass filter) processing is performed by the low pass filter 26a.

Here, the constant interval averaging process adds 10 pieces of data for 10 msec sampled at 1000 Hz to be a data string (a). Then, the average of the data string a is calculated every 1 sec, so as to be the data string b.

The adaptive LPF (low pass filter) processing updates the reference voltage with the following processing for each of the above average processing,

New reference voltage = (average value for 1 second × α + old reference voltage × β) ÷ (α + β)

Output with zero smoothed reference voltage.

Here, the values of alpha and beta are constant values, i.e., alpha = 1 and beta = 199, but the implementation state of changing and adjusting in accordance with the signal from the discrimination circuit 41 constituting the above-described posture stability discriminating means is adopted. It is also possible. If alpha is large, the followability to zero variation is improved, and if alpha is small, the error is reduced due to disturbance or the like, and the accuracy of the correction operation is improved. That is, based on the signal from the discriminating circuit 41, the higher the attitude stability of the traveling gas is set, the higher the cutoff frequency of the low pass filter 26b is set, and the lower the attitude stability of the traveling gas, the lower the cutoff of the low pass filter. The frequency is set low. It is also appropriate to stop the process and not to calculate the wrong reference voltage during turning or during large slope changes.

In the case where α and β are automatically adjusted, the embodiment in which the number of sampling outputs is constant in the average value calculation by the average calculation processing means 26a may be adopted.

In either case, since all errors cannot be eliminated in the first error correction G1, there is an error in the linearity of the sensor further, and the accumulation of the error due to the integration process cannot be eliminated.

Therefore, in order to eliminate the error accumulated once, the second error compensation G2 which feeds back the deviation from the detection inclination angle? R by the inclination sensor 15 to the target inclination angle? Set by the inclination setter 20. Is done. Here, if the feedback coefficient K2 can be set sufficiently small, the absolute accuracy equivalent to the inclination sensor 15 is ensured when the machine stops, θ = θr, and the response that is not influenced by the lateral fluctuations when the slope changes. Good tilt angle can be output. On the contrary, when K2 is large, the effect of the compensation of θr will be excessive and it will not change to the output value of the inclination sensor 15.

Here, since the feedback coefficient K2 needs to be set according to the accumulated error, the more the precision of the gyro sensor is used, the smaller the first error compensation G1 can be devised. In the above-described processing, the error can be eliminated at about 0.5%, which is a value small enough to satisfy the required capability. However, when the temperature change is severe or when a cheaper gyro sensor is used, it is necessary to make it larger, and it is necessary to evaluate how much the performance deterioration is caused by it.

It is also preferable to make the feedback coefficient K2 variable. For example, when stopping or when there is little change in slope, increase K2 to quickly remove the error of the target inclination angle (θ) .In contrast, when working or when change of slope is severe, the feedback coefficient (K2) is reduced to influence the influence of lateral fluctuation. Inhibition improves responsiveness. In addition, in a condition where the error of the gyro sensor becomes large, such as immediately after starting, or when the temperature change is large, the feedback coefficient (K2) is increased to remove the error, and when the temperature is stable, the feedback coefficient (K2) is regarded as important to the responsiveness. do.

For reference, Fig. 4 and Fig. 5 show the detection operation test results of the sensors 15 and 23 when the inclination of the tractor changes.

According to Fig. 4, with respect to the inclination change of the traveling gas, the output by the calculation of the angular velocity sensor 23 changes almost without time delay, whereas the inclination sensor 15 changes with a time delay of about 0.5 seconds. In addition, it can be understood that when the inclination starts to change in the positive direction and when the change starts in the negative direction, the inertia is temporarily detected as the reverse movement. 4 and 5, v is the left and right tilt angles of the traveling body 21, y is the output by calculation of the angular velocity sensor, and z is the tilt sensor output.

Fig. 5 shows an example in which the change of the inclination is faster than that in Fig. 4, and shows the change characteristic of the output by the calculation of the inclination sensor 15 and the angular velocity sensor 23 when the change of about 2 degrees occurs in 0.5 second. According to this, the inclination sensor 15 outputs about 1 degree in the reverse direction at the start of lowering and rising, and overshoots at the time of elevating stopping. On the other hand, it turns out that the output by the calculation of the angular speed sensor 23 is also following the inclination change of the traveling gas. Thus, it is clear that the control based on the output of the angular velocity sensor is superior in the responsiveness and precision than the output of the inclination sensor.

(Other embodiment)

In this other embodiment, as shown in FIG. 6, a temperature sensor 38 for detecting the temperature of the angular velocity sensor 23 is provided, and the state sensor 38 and the discrimination circuit 41 determine the state stability. Is being built. Since the temperature change of the angular velocity sensor 23 is a factor that greatly affects the variation of the sensor zero, the state stability of the working gas is detected by determining the signal from the temperature sensor 38 which detects this. In this other embodiment, the zero point correcting means 26 is the sampling from the angular velocity sensor 23 in the constant interval average processing by the average arithmetic processing means 26a, the smaller the temperature change of the angular velocity sensor 23 is. It has a function of setting the number of output values to be large, and setting the number of sampling output values to be smaller as the temperature change of the angular velocity sensor 23 is larger.

The angular velocity sensor 23 is arranged at a distance from the transmission case 3, but is affected by the ambient temperature due to the temperature change of the transmission case 3. Since the temperature of the transmission case 3 depends on the engine temperature, the temperature of the angular velocity sensor 23 is clearly different immediately after the engine is started and after the engine is sufficiently warmed, whereby the zero point drifts. do. In addition to the engine, the ambient temperature of the angular velocity sensor 23 (an example of the state stability of the traveling gas 21) is different depending on various conditions such as season, climate, region, and geography. Change the number.

Further, the zero correction means 26 indicates that the smaller the temperature change of the angular velocity sensor 23, that is, the lower the state stability, the α in the adaptive LPF (low pass filter) processing by the low pass filter 26b. The larger the temperature change of the angular velocity sensor 23, that is, the higher the state stability, the smaller the α.

Based on the result of the state stability discriminating means, it is preferable that the automatic adjustment function of the control parameters of the average arithmetic processing means 26a or the low pass filter 26b have both functions. It is just good.

(Variation)

&Quot; 1 " As the posture stability determining means, the angular velocity sensor 23 can be used instead of the vehicle speed sensor 27 for the detection of the posture stability of the earth work device 4 or the traveling body 21. At that time, the zero point correction means 26 sets the number of sampling output values by the angular velocity sensor 23 to be smaller as the output value of the angular velocity sensor 23 is smaller, and the number of sampling output values as the output value of the angular velocity sensor 23 is larger. Set a lot. Similarly, the value of α of the low pass filter 26b is also adjusted according to the posture stability.

&Quot; 2 " As the posture stability determining means, the inclination sensor 15 can be used instead of the vehicle speed sensor 27 for the detection of the posture stability of the earth work device 4 or the traveling body 21. At that time, the zero point correction means 26 sets the number of sampling output values by the angular velocity sensor 23 to be smaller as the output value of the inclination sensor 15 is smaller, and as the output value of the inclination sensor 15 is larger, Set the number to large. Similarly, the value of α of the low pass filter 26b is also adjusted according to the posture stability.

&Quot; 3 " As shown in Fig. 7, the posture stability discriminating means includes a potentiometer type angle angle sensor 33 for detecting the angle of angle of steering wheel 31, and the zero point correcting means 26 is steered. The smaller the angle of rotation of the front wheels 31, the smaller the number of sampling output values by the angular velocity sensor 23, and the larger the angle of rotation of the steering front wheels 31, the larger the number of sampling output values. Similarly, the value of α of the low pass filter 26b is also adjusted according to the posture stability.

&Quot; 4 " As shown in Fig. 8, the state stability determining means is provided with a timer 40 (an example of the time measuring means) for detecting the elapsed time from when the main switch 39 is turned on. In other words, the engine temperature, i.e., the ambient temperature of the angular velocity sensor 23, is completely different immediately after engine startup and after warming up. To change. That is, the shorter the elapsed time after the ON operation of the main key 39, the lower the atmospheric temperature of the angular velocity sensor 23, and the longer the elapsed time, the higher the atmospheric temperature of the angular velocity sensor 23. Therefore, the zero point correction means 26 sets the number of sampling output values by the angular velocity sensor 23 to be larger as the time since the main switch 39 is turned on, and the time since the main switch 39 is turned on. The shorter the value, the smaller the number of sampling output values. Similarly, the value of α of the low pass filter 26b is also adjusted according to the state stability.

&Quot; 5 " As another example of the posture stability determining means for discriminating the high and low posture stability of the earth work device 4 or the traveling body 21, pitching for detecting the inclination of the earth work device 4 or the body 21. Various changes are possible, such as the sensor, the angular velocity sensor related to the pitching, the angular velocity sensor in the up-down direction of the earth work device 4 or the aircraft 21, the amount of operation of the accelerator lever or pedal, the height of the shift stage (position), etc. .

As another example of the state stability determining means for discriminating the high and low state stability of the earth work device 4 or the traveling body 21, various modifications such as a thermometer, a hygrometer, and an altimeter can be made. In addition, in this embodiment, you may arrange | position the inclination sensor 15 and the angular velocity sensor 23 on the earth work apparatus 4 side. As the ground work device 4, various modifications, such as a planting device, a wave directing device, a paddy field production device, and a stationary device, can be made in addition to the tilling device.

<< 6 >> In the description of the above embodiment, an agricultural tractor is used as the working machine. Of course, the technique of the present invention is also applicable to tractors, combines, and other various working machines used for civil works.

According to the present invention, even in a work machine that is always in operation such as a tractor, it is possible to accurately perform zero calibration of an angular velocity sensor that drifts due to temperature change and the like. It can be practically realized.

Claims (12)

An actuator that connects the earth work device to the rolling free-rolling body, and rolls and drives the land work device with respect to the travel gas, an inclination sensor for detecting the left and right inclination angles of the travel gas or the earth work device, and the travel gas Or an angular velocity sensor for detecting an angular velocity in the left and right inclined directions of the earth work device, and based on the detected values of both the inclination sensor and the angular speed sensor, the posture of the earth work device is set at a set angle. In the sensor zero correction device of the working machine which is provided with a rolling control means for operating the actuator to be maintained, Average arithmetic processing means for calculating an average value based on a sampling output value detected by the angular velocity sensor, zero control means for zeroing the average value obtained by this averaging processing means, and high and low posture stability of the traveling body; And posture stability means for discriminating The higher the posture stability of the traveling gas is set, the smaller the number of sampling output values used for the average calculation process, and the lower the posture stability of the traveling gas is set, the greater the number of sampling output values used for the calculation process. Sensor zero correction device. An actuator that connects the earth work device to the rolling free-rolling body, and rolls and drives the land work device with respect to the travel gas, an inclination sensor for detecting the left and right inclination angles of the travel gas or the earth work device, and the travel gas Or an angular velocity sensor for detecting an angular velocity in the left and right inclined directions of the earth work device, and based on the detected values of both the inclination sensor and the angular speed sensor, the posture of the earth work device is set at a set angle. In the sensor zero correction device of the working machine which is provided with a rolling control means for operating the actuator to be maintained, A low pass filter for performing low pass filter processing on the sampling output value detected by the angular velocity sensor, zero control means for zeroing the output value of the low pass filter, and a posture for discriminating the high and low posture stability of the traveling gas. And stability stability means The higher the posture stability of the traveling gas is, the higher the cutoff frequency of the low pass filter is set, and the lower the posture stability of the traveling gas is set, the lower the cutoff frequency of the low pass filter is set. Device. An actuator that connects the earth work device to the rolling free-rolling body, and rolls and drives the land work device with respect to the travel gas, an inclination sensor for detecting the left and right inclination angles of the travel gas or the earth work device, and the travel gas Or an angular velocity sensor for detecting an angular velocity in the left and right inclined directions of the earth work device, and based on the detected values of both the inclination sensor and the angular speed sensor, the posture of the earth work device is set at a set angle. In the sensor zero correction device of the working machine which is provided with a rolling control means for operating the actuator to be maintained, An average arithmetic processing means for calculating an average value based on the sampling output value detected by the angular velocity sensor, a low pass filter for performing a low pass filter process on the average value obtained by the average arithmetic processing means, and an output of the low pass filter. A zero point control means having a zero value and a posture stability determining means for discriminating between high and low posture stability of the traveling gas; The higher the posture stability of the traveling gas is set, the smaller the number of sampling output values used for the average calculation process, and the lower the posture stability of the traveling gas is set, the larger the number of sampling output values used for the calculation process is set. The higher the posture stability of the traveling gas is, the higher the cutoff frequency of the low pass filter is set, and the lower the posture stability of the traveling gas is set, the lower the cutoff frequency of the low pass filter is set. Device. 4. The sensor zero correction device for a work machine according to any one of claims 1 to 3, wherein said attitude stability determining means is a vehicle speed sensor for detecting a traveling speed of said traveling body. 4. The apparatus for correcting a sensor zero of a work machine according to any one of claims 1 to 3, wherein said posture stability determining means is said angular velocity sensor. The apparatus for correcting the sensor zero of any one of claims 1 to 3, wherein the posture stability determining means is the inclination sensor. 4. A sensor zero correction apparatus for a work machine according to any one of claims 1 to 3, wherein said posture stability determining means is a bending angle sensor for detecting a bending angle of a steering wheel. An actuator that connects the earth work device to the rolling free-rolling body, and rolls and drives the land work device with respect to the travel gas, an inclination sensor for detecting the left and right inclination angles of the travel gas or the earth work device, and the travel gas Or an angular velocity sensor for detecting an angular velocity in the left and right inclined directions of the earth work device, and based on the detected values of both the inclination sensor and the angular speed sensor, the posture of the earth work device is set at a set angle. In the sensor zero correction device of the working machine which is provided with a rolling control means for operating the actuator to be maintained, Average arithmetic processing means for calculating an average value based on the sampling output value detected by the angular velocity sensor, zero control means for making the average value obtained by this average arithmetic processing means zero, and a state influencing fluctuations in the sensor zero State stability discrimination means for discriminating between high and low stability is provided, and And the higher the state stability, the greater the number of sampling output values used for the average calculation process, and the lower the state stability, the lower the number of sampling output values used for the calculation process is set. An actuator that connects the earth work device to the rolling free-rolling body, and rolls and drives the land work device with respect to the travel gas, an inclination sensor for detecting the left and right inclination angles of the travel gas or the earth work device, and the travel gas Or an angular velocity sensor for detecting an angular velocity in the left and right inclined directions of the earth work device, and based on the detected values of both the inclination sensor and the angular speed sensor, the posture of the earth work device is set at a set angle. In the sensor zero correction device of the working machine which is provided with a rolling control means for operating the actuator to be maintained, A low pass filter for performing low pass filter processing on the sampling output value detected by the angular velocity sensor, zero control means for zeroing the output value of the low pass filter, and high and low state stability affecting the variation of the sensor zero. And state stability discriminating means for discriminating The cutoff frequency of the low pass filter is set lower as the state stability is higher, and the cutoff frequency of the low pass filter is set higher as the state stability is lower. An actuator that connects the earth work device to the rolling free-rolling body, and rolls and drives the land work device with respect to the travel gas, an inclination sensor for detecting the left and right inclination angles of the travel gas or the earth work device, and the travel gas Or an angular velocity sensor for detecting an angular velocity in the left and right inclined directions of the earth work device, and based on the detected values of both the inclination sensor and the angular speed sensor, the posture of the earth work device is set at a set angle. In the sensor zero correction device of the working machine which is provided with a rolling control means for operating the actuator to be maintained, An average arithmetic processing means for calculating an average value based on the sampling output value detected by the angular velocity sensor, a low pass filter for performing a low pass filter process on the average value obtained by the average arithmetic processing means, and an output of the low pass filter. A zero point control means having a zero value, and a state stability determining means for discriminating between high and low state stability affecting a change in sensor zero, and The higher the state stability is, the larger the number of sampling output values used for the average calculation process is set. The lower the state stability, the smaller the number of sampling output values used for the calculation process is set. The cutoff frequency of the low pass filter is set lower as the state stability is higher, and the cutoff frequency of the low pass filter is set higher as the state stability is lower. 11. The sensor zero correction device according to any one of claims 8 to 10, wherein said state stability determining means is a temperature sensor for detecting a temperature of said angular velocity sensor. 11. A sensor zero correction device for a work machine according to any one of claims 8 to 10, wherein said state stability determining means is a time measuring means for detecting an elapsed time from when the main switch is turned on.