JPH09318384A - Error correcting method for movement detecting sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct or absorb the error of a movement detecting sensor for detecting the movement such as an angular velocity and to remove the effect of the error. SOLUTION: A CPU 14 performs the offset correction of the voltage, which is outputted from a signal processing circuit 12 as the detected signal of a vibration gyro 11, when a vehicle-speed monitoring means 15, a stopping-time- operation monitoring means 21 and the like perform the detection indicating the stopped state of a vehicle. The stopped state is judged and offset correction can be performed even when the difference of the fluctuations of the output voltages at the time of stopping and at the time of straight-line running is utilized. For the CPU 14, the C/N ratio signal indicating the receiving state is also given from a tuner 16, which receives the radio wave from a broadcast satellite 19. The stopped state and the stright-line running state are judged by the level fluctuation of the signal, and the offset correction of the output voltage of the signal processing circuit 12 can be also performed. Furthermore, the error correction of the sensitivity of the vibration gyro 11 can be performed by utilizing the operation of an automatic tracking device 20 for directing a directional beam 18 of an antenna 17 toward the broadcasting satellite 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting an error of a movement detecting sensor which is mounted on or carried in a moving body such as an automobile and which detects a moving state amount of the moving body such as an angular velocity.

[0002]

2. Description of the Related Art Conventionally, various types of movement detection sensors for measuring the amount of movement have been used for moving bodies such as automobiles, ships, airplanes and railway vehicles. An angular velocity sensor for detecting a change in direction of a moving body is used as a direction detecting means for estimating a current position by dead reckoning in a navigation device or the like. With an angular velocity sensor,
It is possible to detect how much the traveling direction of the moving body has changed during the movement with reference to the traveling direction before the start of the movement.

Conventionally, as a sensor for detecting an angular velocity, for example, JP-A-2-212711 and JP-A-2-29 are known.
The vibration gyro disclosed in, for example, 3620 is widely used. FIG. 13 shows a configuration for using the vibration gyro as an angular velocity sensor. With the vibration gyro 1,
An ultrasonic vibrator having a prismatic shape such as a square prism or a triangular prism is held and vibrated so that the axis line is in the vertical direction. Clockwise (CW) around the vertical axis or counterclockwise (CC
The vibration state changes due to the Coriolis force generated during the angular displacement of (W). The signal processing circuit 2 electrically detects this change. The output voltage of the signal processing circuit 2 is analog /
It is converted into a digital value by a digital (hereinafter abbreviated as "A / D") converter 3 and becomes input data to the navigation device by the CPU 4.

FIG. 14 shows output characteristics of the vibration gyro 1 shown in FIG. 13 as an angular velocity sensor. The horizontal axis represents the actual angular velocity, and the vertical axis represents the value of the detected angular velocity data output from the A / D converter 3 in FIG. The ideal characteristic is shown by the solid line, but the sensitivity Sv at this time is
Is defined as a and the offset voltage Vo is defined as b, an error due to a difference in sensitivity Sv as indicated by a broken line and an error in offset voltage Vo as indicated by a thick solid line occur. Such an error fluctuates with the passage of time, and for example, Japanese Patent Laid-Open No.
No. 189514 discloses a prior art for correcting error drift.

[0005]

[Patent Document 1] Japanese Patent Application Laid-Open No. 3-18951
In the prior art of No. 4, the stopped state of the automobile is detected by the output from the vehicle speed sensor. When correcting the offset value, a history of changes in the offset value is stored, the tendency of the change is predicted, and drift correction is performed. Since the stop state is detected by the vehicle speed pulse, it can be used when it is difficult to use the vehicle speed pulse signal, such as when a user such as an automobile later wears a device equipped with a vibration gyro. Can not.

In the angular velocity sensor using the vibration gyro,
Since an error occurs between the output voltage value Vo at rest and the sensitivity Sv due to the influence of the elapsed time after startup, temperature, power supply voltage, or the like, a difference occurs between the actual angular velocity and the detected angular velocity shown in FIG. An error may occur. In order to correct or absorb the error and eliminate the effect, it is possible to change the temperature or the power supply voltage by only predicting the drift from the tendency of the temporal change as in the prior art disclosed in Japanese Patent Laid-Open No. 3-189514. No corresponding prediction can be made.

An object of the present invention is to provide an error correction method for a movement detection sensor capable of appropriately and accurately correcting an error of a movement detection sensor such as an angular velocity sensor in association with the movement of a moving body. .

[0008]

SUMMARY OF THE INVENTION The present invention is a method for correcting an error of a movement detection sensor mounted on a moving body and detecting a predetermined moving state amount of the moving body, which is used when the moving body is stopped and when the moving body is moved. An error correction method for a movement detection sensor, which monitors a phenomenon that changes with time and corrects the error of the movement detection sensor when the output value of the movement detection sensor is used as an offset value when a state corresponding to a stop is reached. is there. According to the present invention, a phenomenon that changes between when a moving body is stopped and when it is moving, for example, a vehicle speed pulse signal is monitored, and when the vehicle speed pulse signal is fixed at a high level or a low level and does not change as a pulse. , The error is corrected by using the output value of the movement detection sensor as an offset value. When the level of the vehicle speed pulse signal is fixed, the output of the movement detection sensor becomes an offset value because the automobile, which is a moving body, is stopped or is moving at an extremely low speed.
When the offset value is updated, the error in the detection value of the movement amount based on the offset value is eliminated, and the movement amount can be detected accurately.

Further, the present invention is characterized in that, as the phenomenon, a change in an indicated value of an indicator provided on the moving body is monitored. According to the present invention, an indicator provided on the moving body,
For example, if the change in the indication value of the speed indicator or the engine tachometer is monitored and it is recognized that the speed indication value is 0 or the engine rotation indication value is in the idling state, it is determined that the vehicle as the moving body is in the stopped state. You can judge.

Further, the present invention is a method for correcting an error of a movement detection sensor for detecting a movement state quantity, which monitors the output of the movement detection sensor and, when the variation of the output is within a predetermined range, a variation range. The error correction method for a movement detection sensor is characterized by correcting an error of the movement detection sensor using an output value according to a preset condition as an offset value. According to the present invention, the output of the movement detection sensor itself, which is mounted on or brought into the moving body, is monitored, and when the variation of the output of the movement detection sensor is small so as to be within a predetermined range, the moving body is in the stopped state. It can be determined that the output value according to a preset condition such as the average value or the central value of the output values at that time is used as an offset value to reduce the error of the movement detection sensor and improve the detection accuracy. When moving, the output value of the movement detection sensor fluctuates greatly, and the movement amount detected by the movement detection sensor is 0 and the movement amount detected is 0, as when the vehicle is moving straight ahead. The fluctuation will be large. Since the offset adjustment can be performed in a state where there is little fluctuation, it is possible to improve the detection accuracy after correction.

Further, the present invention is a method for correcting an error of a movement detecting sensor mounted on a moving body for detecting a predetermined moving state amount of the moving body, which method receives a radio wave transmitted from a stationary transmission source. A method for correcting an error of a movement detection sensor, characterized in that when a received radio wave is stably received according to a predetermined standard, an error of the movement detection sensor is corrected using an output value of the movement detection sensor as an offset value. . According to the present invention, the stationary state of the moving body is determined by the stability of the receiving state of the radio wave transmitted from the stationary source. When the moving body is in the stationary state, it is possible to stably receive the radio wave from the stationary source, and thus it is possible to easily determine whether or not the moving body is in the stationary state.

Further, according to the present invention, in order to receive the radio wave, the direction of the directional beam of the antenna is changed to a direction determined based on the output of the movement detection sensor, and a constant electric field strength is obtained at a constant speed. It is characterized by swinging the head to absorb the error of the movement detection sensor. According to the present invention, the direction of the directional beam of the broadcast receiving antenna is changed within a certain range based on the output of the movement detection sensor.
If the direction in which the electric wave reception is the maximum electric field strength is included, the error of the movement detection sensor is absorbed, and the electric wave can be received in a high electric field strength state even when the moving body is not stationary.

Further, according to the present invention, in order to receive the radio wave, the direction of the directional beam of the antenna is changed to a direction determined based on the output of the movement detection sensor, and a constant electric field strength can be obtained at a constant speed. It is characterized by correcting the error of the output value of the movement detection sensor with respect to the movement amount based on the difference between the direction in which the electric field strength is maximum and the direction based on the output of the movement detection sensor. To do. According to the present invention, the sensitivity error with respect to the movement amount of the movement detection sensor is corrected in accordance with the difference between the direction in which the maximum electric field strength of the broadcast wave is the maximum and the direction determined based on the output of the movement detection sensor. In general, it is possible to effectively correct the sensitivity that is harder to correct than the offset value.

Further, the present invention is a method for correcting an error of a movement detection sensor which is mounted on a moving body and detects a predetermined moving state amount of the moving body, and monitors the presence or absence of an operation performed when the moving body is stopped. However, when it is determined that the moving body is stopped by the operation, the error of the movement detection sensor is corrected by using the output value of the movement detection sensor as an offset value. Is the way. According to the present invention, the stop of the moving body is determined by monitoring the presence or absence of an operation performed at the time of stopping, so even if a signal indicating the movement of the moving body such as a vehicle speed pulse cannot be directly obtained, the moving body can be surely obtained. It is possible to determine the stop state of the moving body.

Further, in the invention, it is characterized in that the operation is performed for braking the moving body. According to the present invention,
By judging that the moving body is in a stopped state by the operation of braking the moving body, it is possible to reliably judge the stopping of the moving body,
Offset correction can be reliably performed.

In the present invention, the operation is performed to open an openable / closable portion of the body-related exterior portion of the moving body. According to the present invention, when the openable / closable portion of the exterior portion of the body of the moving body, such as the bonnet of a car, the front and rear doors, the fuel filler, etc., is opened, it is determined that the vehicle is stopped. Since the open state is an operation performed in the stopped state, it is possible to reliably detect the stopped state and accurately perform offset correction.

Further, according to the present invention, the operation is performed to stop the transmission of the driving force for moving the moving body. According to the present invention, when the moving body is stopped, the driving force transmission for moving the moving body is decelerated and stopped. When the moving body is an automobile, for example, the shift lever for shifting is in the neutral position or the key position is in the accessory (ACC) position. By monitoring these operations, it is possible to easily detect whether or not the moving body is in the stopped state.

In the present invention, the moving body is a vehicle capable of changing the driver's seat between a driving state and a reclining state,
The operation is performed to put the driver's seat in a reclining state. According to the present invention, if the driver's seat of the vehicle can be changed between the driving state and the reclining state, it can be easily determined that the vehicle is in the stopped state when the driver's seat is changed to the reclining state.

Furthermore, the present invention is a method for correcting an error of a movement detection sensor for detecting a movement state quantity, which monitors movement of a moving body in a direction detected by the movement detection sensor and detects a direction detected by the movement sensor. When it is determined that the movement of the movement detection sensor is stopped, the error value of the movement detection sensor is corrected by using the output value of the movement detection sensor as an offset value. According to the present invention,
Movement related to a direction detected by the movement detection sensor, for example, a change in movement direction in the case of an angular velocity sensor, and change in movement speed in the case of an acceleration sensor is monitored. When the movement to be monitored is not performed, the output value of the movement detection sensor can be determined to be the offset value, the detection error can be reduced by updating the offset, and the movement amount detection accuracy can be improved.

Furthermore, the present invention is a method for correcting an error of a movement detecting sensor mounted on a moving body and detecting a predetermined moving state amount of the moving body, which shows the relationship between the operating condition of the moving detection sensor and the error. An error correction method for a movement detection sensor, which is characterized by making a table in advance, monitoring the operating conditions of the movement detection sensor, and referring to the table to correct the error of the movement detection sensor. According to the present invention, the relationship of the errors caused by various operating conditions of the movement detection sensor is tabulated in advance, so that the errors corresponding to the operating conditions can be accurately corrected.

Further, in the invention, it is characterized in that the movement detecting sensor detects an angular velocity. According to the present invention, it is possible to appropriately correct an error such as an offset value or sensitivity of a sensor that detects an angular velocity, and improve detection accuracy.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a schematic electrical configuration for correcting an error of a movement detection sensor mounted on a vehicle such as an automobile according to an embodiment of the present invention. The vibration gyro 11, which is a movement detection sensor, includes a signal processing circuit 12
An angular velocity based on the Coriolis force acting according to a clockwise (CW) or counterclockwise (CCW) angular displacement around the axis of the vibrating gyro 11 is detected from the change in the vibrating state. The output voltage from the signal processing circuit 12 is converted into digital data by the A / D converter 13 and input to the CPU 14 as data representing the angular velocity.

To the CPU 14, a signal from the vehicle speed monitoring means 15 such as a vehicle speed pulse signal, a C / N ratio signal indicating a reception state from the tuner 16 for receiving satellite broadcasting, etc. are inputted. The tuner 16 always directs the directional beam 18 of the antenna 17 toward the broadcasting satellite (BS) 19.
The tracking operation is being performed by the automatic tracking device 20. CPU1
Output signals from the operation monitoring means 21 during stop, the steering operation monitoring means 22 and the like are also input to 4. Also, operating condition monitoring means 2 for monitoring the operating conditions of the vibration gyro 11
Output data from 3 is also input, and the error of the vibration gyro 11 is corrected by referring to a preset table 24. The CPU 14 further includes a map matching from a navigation device 25 for guiding the traveling of the vehicle and a GPS.
Data indicating the current position using satellite radio waves is also input.

FIG. 2 shows the operation of the CPU 14 of FIG.
The CPU 14 repeatedly executes a series of control programs as a loop, and performs the operation shown in FIG. 2 as a part thereof. The operation is started from step a1, and the output g of the vibration gyro 11 is measured at step a2. A / D converter 13
If the output data from x is x, then g = x.
Next, in step a3, the angular velocity v is calculated based on the output g of the vibration gyro 11. The angular velocity v is calculated by the following first
It is done according to the formula.

[0025]

[Equation 1]

Vo is a reference output value at the time of stop,
The offset value of the output of the vibration gyro 11 is represented. At step a4, it is judged from the output from the vehicle speed monitoring means 15 whether or not the vehicle speed is zero. For example, if there is no vehicle speed pulse output and the vehicle speed pulse output is fixed at a high level or a low level, it can be determined that the vehicle, which is a moving body, is in a stopped state. When it is determined that the vehicle speed is 0, the offset value Vo is replaced with the value x in step a5. As the offset value Vo and the sensitivity Sv, the default value is stored in the memory in advance, and is replaced with a corrected value to be updated. The memory is battery backed up and the updated values are retained. Step a4
When it is determined that the vehicle speed is not 0, the actuator operation control is performed in step a6 using the angular velocity v. The actuator is, for example, a drive motor provided in the automatic tracking device 20 or a current position calculation based on dead reckoning in the navigation device 25. Upon completion of step a5 or step a6, the process moves to the next control loop in step a7.

FIG. 3 shows the navigation device 2 shown in FIG.
The amount of change in the direction of the vehicle calculated by 5 is shown in (a), and the amount of change in the moving direction calculated from the cumulative output value of the angular velocity detected by the vibration gyro 11 is shown in (b). It is assumed that the movement direction change amount of the navigation device 25 shown in (a) changes from 0 degree to a degree.
Change amount F (Sv) based on accumulation of angular velocities shown in (b)
Is a relative difference before and after the start of the direction change, the offset value Vo is offset and depends on the sensitivity Sv. By comparing the direction change detected by the navigation device 25 and the cumulative value of the angular velocity, the error of the sensitivity Sv can be calculated and the value of the sensitivity Sv can be corrected.

FIG. 4 shows changes in the output voltage of the signal processing circuit 12 corresponding to the angular velocity detected by the vibration gyro 11. The fluctuation of the output of the signal processing circuit 12 is different between when the vehicle is stopped and when the vehicle is traveling straight due to the influence of vibrations and the like applied to the vehicle. (A) shows the output voltage fluctuation state when the vehicle is stopped, and (b) shows the output voltage fluctuation state when the vehicle is running straight. While the output voltage hardly fluctuates when the vehicle is stopped, when it has a sensitivity of about 20 mV for an angular velocity of 1 degree / sec, for example, when the vehicle is running straight, the output voltage is several
It produces a small variation in pp. Utilizing this fact, if the fluctuation of the output from the signal processing circuit 12 is monitored, vehicle speed = 0 in step a4 of the operation of FIG. 2 depending on whether or not the fluctuation width is smaller than a reference set to about 10 mV. It is possible to determine the vehicle stop state corresponding to.

In the configuration shown in FIG. 1, the vehicle is equipped with an automatic tracking device 20 for directing the directional beam 18 of the antenna 17 toward the broadcasting satellite 19 in order to receive satellite broadcasting. The broadcast satellite 19 has been launched into a geostationary satellite orbit above the equator, and if the vehicle is stopped, the directional beam 1
Radio waves can be received even if the direction of 8 is fixed. If the vehicle is moving, control is performed such that the directional beam 18 is changed by the automatic tracking device 20 and the broadcasting satellite 19 is always tracked. Radio waves transmitted from the broadcasting satellite 19 are received by the tuner 16, and a C / N ratio signal representing the ratio of the reception intensity of carrier waves to the reception intensity of noise is given to the CPU 14. The detected voltage of the C / N ratio signal varies little if the vehicle is stopped and the reception state is stable, and if the vehicle is moving, it varies due to noise or the like even if the reception state is stable. If the reception status becomes unstable due to the movement of the vehicle,
It fluctuates even more. Therefore, as in the case of the change in the output voltage of the signal processing circuit 12 shown in FIG. 4, if the fluctuation range is small, it can be judged that the vehicle is in a stopped state, and the judgment of vehicle speed = 0, which is equivalent to step a4 in FIG. It can be carried out.

FIG. 5 shows in a state (a) the vehicle 30 is stopped at a certain angle with respect to the broadcasting satellite 19 or is traveling straight, and the vehicle is traveling in a curve where the direction changes. The state is shown in (b). The automatic tracking device 20 that changes the direction of the directional beam 18 of the antenna 17 swings toward the broadcasting satellite 19 at a constant speed. The swing is
This is performed until the C / N ratio level received in the clockwise direction and the counterclockwise direction in the horizontal plane with respect to the direction of the broadcasting satellite 19 decreases by a certain value or until a certain angle is reached. As shown in FIG. 5, when swinging left and right around the broadcasting satellite 19, C / N as shown in FIG.
A change in the ratio signal level is obtained. FIG. 6A shows FIG.
6A corresponds to FIG. 5B.
As shown in (a) of FIG. 5 and FIG. 6, when the vehicle 30 is stopped or running straight, the swing time is the same on the left and right sides. If the vehicle is traveling on a curve as shown in FIG. 5B, the swing times t1 and t2 are different between the left and right as shown in FIG. 6B. Since the determination as to whether or not the vehicle is stopped in step a4 of FIG. 2 is performed to determine the timing for correcting the offset value, the case where the vehicle is stopped or running straight as shown in FIG. Also, the offset value can be corrected. That is, as shown in FIG. 6A, if the condition that the left and right swing times t1 and t2 are the same is satisfied, it is determined that the condition suitable for the offset correction similar to step a4 in FIG. 2 is satisfied. can do.

FIG. 7 shows the sensitivity Sv [mV for detecting the angular velocity.
/ Deg / sec] causes an error due to some influence, a concept for correcting by using the automatic tracking function of the automatic tracking device 20 for satellite broadcast reception will be described. Figure 7
As shown in (a), when the vehicle 30 changes its traveling direction, such as when traveling on a curve, the difference (x−) between the actual angular velocity x and the detected angular velocity y detected by the vibration gyro 11 is obtained.
y) may occur. FIG. 7B shows a state in which the direction of the broadcasting satellite 19 and the direction of the directional beam 18 at which the reception level is maximum coincide with each other when no error occurs when x = y. FIG. 7C shows a state in which there is a difference in the direction of the directional beam 18 having the maximum reception level with respect to the direction of the broadcasting satellite 19 when x ≠ y.

As shown in FIG. 7C, the directional beam 18
When the direction is deviated, according to the operation shown in FIG. 8, the automatic tracking device 20 starts swinging to search for a direction to the broadcasting satellite. The operation is started from step b1 as a part of the control loop for satellite tracking, and step b
In step 2, it is determined whether or not the level of the received C / N ratio signal deviates from the tracking area preset to be trackable. If there is no deviation from the tracking area, automatic tracking continues. When it comes out of the tracking area, in step b3, the swing operation of the broadcasting satellite is started. As a result of the swing motion,
The changes shown in FIGS. 6A and 6B are obtained,
In step b4, it waits until the reception level of the peak value of the change returns to the tracking area. When returning, the swinging motion is stopped in step b5, and the automatic tracking motion according to the output from the vibration gyro 11 is performed. By repeating the control as shown in FIG. 8, even if the sensitivity Sv is deviated, the error can be absorbed and the radio wave from the broadcasting satellite 19 can be stably received.

In the operation of FIG. 8, the error of the output voltage of the vibration gyro 11 can be absorbed, but the absolute sensitivity Sv is not corrected. FIG. 9 shows the operation of a routine for correcting the sensitivity Sv. Such an operation is also performed as part of the control loop in the automatic tracking device 20. The operation of the Sv correction routine is started from step c1, and at step c2, the swing time t1, t as shown in FIG.
Detect a difference of 2. An error correction value of the sensitivity Sv corresponding to the time difference is made into a table in advance, and the correction value is read by referring to the table at step c3. It is also possible to formulate the relationship between the swing time difference and the correction value in advance and obtain the correction value by calculation. In step c4, the sensitivity Sv is corrected based on the correction value, and the process returns to step c2.

The determination of the stopped state of the vehicle in step a4 of FIG. 2 can also be made by detecting an operation performed when the vehicle is stopped. An operation performed when the vehicle is stopped is an operation of applying a brake so that the vehicle, which is a moving body, does not move. The brake operation can be detected by, for example, operating the side brake of the automobile or operating the shift lever of the transmission at the PARKING position. If the vehicle is stopped, an operation of opening an openable / closable portion provided outside the vehicle body of the vehicle is also performed. Examples of such an openable / closable portion include a trunk, a hood, a front or rear door, and a fuel filler. If the vehicle is traveling, these open / close parts are closed.

Further, while the vehicle, which is the moving body, is stopped, the transmission of the driving force from the engine, which is the drive source for moving the moving body, is stopped or the engine itself is stopped. Therefore, instead of determining the vehicle speed = 0 in step a4 of FIG. 2, when the shift lever of the transmission is in the neutral position or when the engine such as the accessory (ACC) of the key switch of the automobile is stopped. If so, it can be determined that the vehicle is stopped. Further, if the function of changing the seat to the reclining state is provided in the driver's seat of the automobile, the vehicle will not be driven in the reclining state, so it can be judged that the vehicle is stopped in the reclining state. .

Further, for example, in a vehicle having a 4WS function such as four-wheel steering, the steering wheel turning angle can be taken out as an electric signal, so that the angular velocity sensor is in a straight running state with the steering wheel turning angle = 0. Therefore, the offset adjustment as a correction becomes possible. Therefore, FIG.
If the steering operation monitoring means 22 is used to judge step a4 in FIG. 2 under the condition of "steering wheel turning angle = 0",
Offset adjustment can be performed in the same manner as when stopped.

FIG. 10 shows an operation for compensating the output value of the vibration gyro 11 by forming a table of the error of the offset value of the vibration gyro 11 in advance with respect to error factors such as temperature, power supply voltage or elapsed time after startup. Indicates. When the error factor is temperature c, the correction value table is set, for example, as shown in Table 1 below.

[0038]

[Table 1]

The operation is started from step d1, and the output g of the vibration gyro 11 is measured at step d2. For example, g = x. In step d3, temperature, power supply voltage, elapsed time, etc. are measured as error factor data,
For example, regarding temperature, c = y. In step d4, the c-Vo table as shown in Table 1 is referred to, and in step d5, offset correction is performed to determine Vo. In step d6, the angular velocity v detected by the vibration gyro 11 is calculated according to the above-mentioned first equation. Step d6
Then, actuator operation control is performed according to the calculated angular velocity, and the routine goes to the next loop in step d8.

In Table 1, the measured value c of the error factor data is
Although it takes discrete values, if it is an intermediate value not shown in Table 1, it is selected as one of the values before and after it. It is preset whether to select the front or back, and the error can be appropriately corrected unless the error factor changes significantly.

FIG. 11 shows the operating condition monitoring means 2 shown in FIG.
As an example of No. 3, the structure for detecting the temperature which becomes an error factor is shown. The change in the resistance value of the thermistor 31 that detects the temperature changes the voltage at the connection point with the resistor 32, and the A / D
It is converted into a digital value by the converter 33 and input as data to the CPU 14. In the table 24, the data correspondence relationship of the temperature and the voltage obtained by the circuit configuration of FIG. 11 is preset, and the change of the temperature which causes the error can be detected accurately.

In FIG. 12, the operating condition monitoring means 23 of FIG.
As another example, a configuration for monitoring a change in the power supply voltage that causes an error in the output voltage of the vibration gyro 11 is shown. The power supply voltage is divided by the resistors 34 and 35, converted into digital data by the A / D converter 36, and the CPU
Given to 14. The CPU 14 refers to a preset table 24, reads the correction value corresponding to the change in the power supply voltage, and corrects the offset value of the output voltage of the vibration gyro 11. The CPU 14 can also measure the elapsed time from the start of the operation and correct the output value of the vibration gyro 11 by using the correspondence between the elapsed time and the correction value preset in the table 24.

In each of the embodiments described above, the case where the movement detecting sensor is the vibration gyro 11 has been described, but the offset value is the same for other types of movement detecting sensors such as a geomagnetic sensor and an acceleration sensor. And sensitivity can be corrected.

Although the source of the received radio wave is the radio wave from the broadcasting satellite 19, the radio wave from the broadcasting station broadcasting the radio wave from the antenna fixed on the ground is also the same. Can be used. However, the broadcasting satellite 19 is stationary over the distant equator,
Since the absolute azimuth hardly changes even when a vehicle or the like moves, it is preferable as a reference for such azimuth detection.

[0045]

As described above, according to the present invention, it is possible to reliably judge the stop state of the moving body and appropriately correct the offset value of the movement detection sensor to improve the detection accuracy.

Further, according to the present invention, the stop state can be surely judged from the change of the indication value of the indicator showing the movement, and the offset correction can be appropriately performed.

Further, according to the present invention, it is possible to reliably judge the stop state from the fluctuation of the output value itself of the movement detection sensor and appropriately perform the offset correction to improve the detection accuracy.

Further, according to the present invention, the direction of the directional beam of the antenna for receiving the radio wave transmitted from the stationary transmission source is changed based on the output of the movement detection sensor so that the electric field strength becomes maximum. Since the offset value of the movement detection sensor can be corrected from the error, the offset correction can be performed even during movement.

Further, according to the present invention, the detection sensitivity of the movement detection sensor can be corrected from the error between the direction of the directional beam based on the output value of the movement detection sensor and the direction of the maximum electric field strength of the received radio wave. Therefore, sensitivity correction, which is generally more difficult than offset correction, can be appropriately performed.

Further, according to the present invention, since the stopped state of the moving body is judged by the presence or absence of the operation performed when the moving body is stopped, the stopped state of the moving body can be surely judged and the offset correction of the movement detecting sensor can be appropriately performed. Can be done.

Further, according to the present invention, the stop state of the moving body can be reliably determined by the braking operation on the moving body.

Further, according to the present invention, it is possible to reliably judge whether or not the moving body is in the stopped state by monitoring the opening of the body exterior portion of the moving body.

Further, according to the present invention, it is possible to reliably judge the stopped state of the moving body by monitoring whether or not the driving force transmission for moving the moving body is stopped.

Further, according to the present invention, it is possible to detect that the driver's seat of the moving body is in the reclining state and to reliably judge the stopped state of the moving body.

Further, according to the present invention, even if the moving body is not stopped, it is possible to reliably judge the state in which the offset of the movement detecting sensor can be corrected, and to appropriately perform the offset correction.

Furthermore, according to the present invention, the relationship between the operating condition of the movement detecting sensor and the error is tabulated in advance, so that the error of the moving detecting sensor can be appropriately corrected by detecting the operating condition.

Further, according to the present invention, since the movement detecting sensor detects the angular velocity, it is possible to increase the detection accuracy of the angular velocity by appropriately performing the offset correction and the sensitivity correction.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic electrical configuration for performing error correction of a movement detection sensor according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a CPU 14 in FIG.

FIG. 3 is a schematic diagram showing a relationship between a traveling direction change amount obtained from the navigation device 25 of FIG. 1 and a direction change amount obtained from a cumulative value of angular velocities detected by the vibration gyro 11.

FIG. 4 is a graph showing variations in the output voltage from the signal processing circuit 12 of FIG. 1 when the vehicle is stopped and when the vehicle is running straight.

FIG. 5 shows a directional beam 18 of an antenna 17 with respect to a broadcasting satellite when the vehicle is stopped or traveling straight and while traveling on a curve.
FIG. 8 is a schematic diagram showing a state in which a swinging motion that greatly changes the direction of is performed.

6 is a timing chart showing a change characteristic of a C / N ratio signal level corresponding to the swinging motion shown in FIG.

FIG. 7 is an actual angular velocity x when the traveling direction of the vehicle changes.
3A and 3B are schematic diagrams showing the difference between the detected angular velocity y and the direction 18 of the directional beam corresponding to the difference, and the direction of the broadcasting satellite 19.

8 is a flowchart showing an operation of absorbing an error in the sensitivity Sv of the vibration gyro 11 by the swinging operation of the automatic tracking device 20 of FIG.

9 is a flowchart showing an operation of correcting the sensitivity Sv based on a swinging operation of the automatic tracking device 20 of FIG.

10 is a flowchart showing an operation of correcting the offset value of the vibration gyro 11 using the error factor data that is the monitoring target of the operation condition monitoring means 23 of FIG.

11 is a block diagram showing a schematic electrical configuration for detecting temperature as an error factor of the vibration gyro 11 monitored by the operating condition monitoring means 23 of FIG. 1. FIG.

12 is a block diagram showing a schematic electrical configuration for detecting a fluctuation in power supply voltage as an error factor of the vibration gyro 11 monitored by the operating condition monitoring means 23 of FIG.

FIG. 13 is a block diagram showing a schematic electrical configuration for detecting an angular velocity using a conventional vibration gyro.

14 is a graph showing output characteristics of the vibration gyro 11 shown in FIG. 1 as an angular velocity sensor.

[Explanation of symbols]

 11 Vibration Gyro 12 Signal Processing Circuit 13, 33, 36 A / D Converter 14 CPU 15 Vehicle Speed Monitoring Device 16 Tuner 17 Antenna 18 Directional Beam 19 Broadcast Satellite 20 Automatic Tracking Device 21 Stop Operation Monitoring Device 22 Steering Operation Monitoring Device 23 Operation Condition monitoring means 24 Table 25 Navigation device 30 Vehicle 31 Thermistor

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takeshi Kaiya 1-2-2 Goshodori, Hyogo-ku, Kobe-shi, Hyogo Prefecture Fujitsu Ten Limited (72) Inventor Koichi Chikishi 1-chome, Gosho-dori, Hyogo-ku, Hyogo Prefecture No. 28 No. 28 within Fujitsu Ten Co., Ltd. (72) Inventor Harada, Intellectual Education, Aichi Prefecture, Aichi-gun, Nagakute-cho, Oita

Claims (14)

[Claims] 1. A method for correcting an error of a movement detection sensor which is mounted on a moving body and detects a predetermined moving state amount of the moving body, wherein a phenomenon which changes between when the moving body is stopped and when it is moving is monitored. An error correction method for the movement detection sensor is characterized in that, when a state corresponding to a stop is reached, the error of the movement detection sensor is corrected using the output value of the movement detection sensor as an offset value. 2. The error correction method for a movement detection sensor according to claim 1, wherein, as the phenomenon, a change in an indication value of an indicator provided on the moving body is monitored. 3. A method for correcting an error of a movement detection sensor for detecting a movement state quantity, comprising monitoring the output of the movement detection sensor, and when the variation of the output is within a predetermined range, within the variation range, An error correction method for a movement detection sensor, characterized in that an error of the movement detection sensor is corrected using an output value according to a set condition as an offset value. 4. A method for correcting an error of a movement detection sensor, which is mounted on a moving body and detects a predetermined moving state amount of the moving body, comprising: receiving a radio wave transmitted from a stationary source; A method for correcting an error of a movement detection sensor, characterized in that an error of the movement detection sensor is corrected by using an output value of the movement detection sensor as an offset value when a radio wave to be stably received according to a predetermined standard. 5. A head swing in a range in which a direction of a directional beam of an antenna is changed to a direction determined based on an output of a movement detection sensor to receive the radio wave, and a constant electric field strength is obtained at a constant speed. The method for correcting an error of a movement detection sensor according to claim 4, wherein the error of the movement detection sensor is absorbed. 6. A head swing within a range in which a direction of a directional beam of an antenna is changed to a direction determined based on an output of a movement detection sensor for receiving the radio wave, and a constant electric field strength is obtained at a constant speed. And correcting the error in the sensitivity with respect to the amount of movement of the output value of the movement detection sensor based on the difference between the direction in which the electric field strength is maximum and the direction based on the output of the movement detection sensor. 4. The error correction method for the movement detection sensor according to 4 or 5. 7. A method for correcting an error of a movement detection sensor, which is mounted on a moving body and detects a predetermined moving state amount of the moving body, the method comprising: An error correction method for a movement detection sensor, wherein when the moving body is determined to be stopped by performing the above step, the output value of the movement detection sensor is used as an offset value to correct the error of the movement detection sensor. 8. The method for correcting an error of a movement detection sensor according to claim 7, wherein the operation is performed to brake the moving body. 9. The method according to claim 7, wherein the operation is performed to open an openable / closable portion of a body-related exterior portion of the moving body. 10. The error correction method for a movement detection sensor according to claim 7, wherein the operation is performed to stop transmission of a driving force for moving the moving body. 11. The moving body is a vehicle capable of changing a driver's seat between a driving state and a reclining state, and the operation is performed to bring the driver's seat into a reclining state. An error correction method for the movement detection sensor described. 12. A method for correcting an error of a movement detection sensor which is mounted on a movement body and detects a predetermined movement state amount of the movement body, the movement of the movement body being monitored in a direction detected by the movement detection sensor. However, when it is determined that the movement in the direction detected by the movement sensor has stopped, the movement detection sensor error is characterized by correcting the movement detection sensor error using the output value of the movement detection sensor as an offset value. Correction method. 13. A method for correcting an error of a movement detection sensor for detecting a movement state amount, wherein the relationship between the operation condition of the movement detection sensor and the error is tabulated in advance, and the operation condition of the movement detection sensor is monitored. Then, the error correction method of the movement detection sensor is characterized by correcting the error of the movement detection sensor with reference to the table. 14. The error correction method for a movement detection sensor according to claim 1, wherein the movement detection sensor detects an angular velocity.