JP2009115624A - Position computing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem, wherein overall precision becomes worse affected by a computation result of a portion under the state where computation precision gets worse, because the same processing is continued, even under a state where computation precision is deteriorated, in a conventional art. <P>SOLUTION: A position detector is provided with a state measuring part for measuring the state of a moving body; a state quantity calculating part for calculating the quantity of the state of the moving body, based on the state of the moving body; a position calculating part for calculating a position of the moving body; a state estimation part for calculating the estimated value of the state of the moving body; a drift determination part for determining a lateral drift of the moving body with respect to an advancing direction; and a selection part for selecting the estimated value, when the moving body is determined to be drifted by the drift determination part, for selecting the quantity of the state, when the moving body is determined to be not drifted by the drift determination part, and for outputting one out of the selected values to the position calculating part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for calculating the position of a moving body.

  With regard to a technique for calculating the position of a moving body (vehicle or the like) based on information from an internal sensor, there is a method of calculating a position by estimating a true value using a filter from the value of the internal sensor. In order to improve accuracy by this method, there is a mobile body positioning device that calculates and stores a bias amount of a sensor value when the mobile body is stationary and corrects the sensor value (see Patent Document 1).

JP 2005-195395 A

  In Patent Document 1, since the characteristics of the moving object are not taken into consideration, the same process is continued even in a state where the calculation accuracy deteriorates (for example, when the moving object fluctuates). . That is, there is a problem that the overall accuracy is deteriorated due to the influence of the calculation result of the portion where the calculation accuracy is deteriorated.

  Therefore, an object of the present invention is to provide an apparatus that can perform highly accurate position calculation even in a state where the calculation accuracy of the moving body deteriorates.

  In order to solve the above problems, one of the desirable embodiments of the present invention is as follows.

  The position calculation device includes a state measuring unit that measures a moving body state, a state quantity calculating unit that calculates a state quantity of the moving body based on the moving body state, a position calculating unit that calculates a position of the moving body, and a moving body When the state estimation unit that calculates the estimated value of the state, the stagger determination unit that determines whether or not the moving object fluctuates in the lateral direction with respect to the traveling direction, and the stagger determination unit determines that the moving object fluctuates When the estimated value is selected, and the wobbling determination unit determines that the moving body is not wobbling, the selection unit includes a selection unit that selects a state quantity and outputs one of the selected values to the position calculation unit.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is in the state where calculation accuracy deteriorates in a mobile body, the apparatus which can perform a highly accurate position calculation can be provided.

  Hereinafter, examples will be described with reference to the drawings. In this paper, the mobile body is described as a vehicle, but the present invention is not limited to this.

  FIG. 1 is a diagram illustrating a configuration of a position calculation device. The internal information measuring unit 10 (inner world sensor or the like) measures the yaw rate, acceleration, and operation angle of the handle, and these data are input to the state quantity calculation unit 11. The state quantity calculation unit 11 calculates the state quantity of the vehicle. For example, the sensor measurement value is converted from a value such as a voltage into a physical quantity, the sensor offset amount is removed, the straightness is compensated, the coordinate system is corrected, the vehicle lateral direction G (acceleration), the longitudinal direction G, A vehicle state variable such as a yaw angle is output as a vehicle state quantity. Note that the sensor data and the state quantity of the vehicle are examples, and do not specify the type and number of sensor data necessary for the present embodiment, the type of signal in the apparatus, and the like.

  The sensor data and the vehicle state quantity are input to the memory 21. The memory stores the input data over the past several cycles, and outputs the stored data as necessary. Here, the data stored and output in the memory 21 may be only sensor data, only the vehicle state quantity, or both the sensor data and the vehicle state quantity. Moreover, the system which memorize | stores for every fixed time may be used, and the system which memorize | stores for every fixed driving distance may be used.

  The state estimation unit 22 receives the data from the memory 21, estimates the current state amount of the vehicle using data from the past, calculates it as an estimated value of the state of the vehicle, and outputs it. The estimated value of the vehicle state is, for example, the lateral direction G, the virtual front-rear direction G, the virtual yaw angle, etc. of the virtual vehicle.

  In addition, the driving state factor acquisition unit 26 acquires a driving state factor (for example, a steering wheel operating angle, a direction indicator operating state, a wiper switch operating state, etc.) indicating an index indicating the driving state of the moving object, and makes a wobble determination. Input to the unit 25. In this embodiment, the amount of steering angle fluctuation is used as the driving state factor, but other sensor data, vehicle state variables, or signals from other devices may be used. It may be a combination thereof. The driving state factor may be the result of monitoring the driver's state. For example, a seating pressure sensor that senses the sitting posture of the driver, a line-of-sight sensor that detects the driver's gaze direction, an operation status of equipment used in the vehicle such as a mobile phone, and a drink status detection result of the drink holder. Further, the driving state factor may be a detection result of an operation state of a driver's vehicle switches (audio switch, etc.) or a detection result of an operation state of a driver's accelerator pedal, brake pedal, or transmission. good.

  The driver characteristics acquisition unit 27 acquires the characteristics of the driver (such as a handle operation habit) and inputs the characteristics to the wobbling determination unit 25.

  The wobbling determination unit 25 determines whether or not the vehicle state is wobbling based on the amount of fluctuation of the operation angle of the steering wheel or the characteristics of the driver, and outputs the determination result to the selection unit 23 as a switching signal 23C. To do.

  The selection unit 23 selects the vehicle state input 23 </ b> A and the vehicle state estimation value input 23 </ b> B according to the determination result, and outputs the selection result to the position calculation unit 12. Note that the selection unit 23 may mix and output the vehicle state and the estimated value of the vehicle state in an analog manner according to the switching signal. Further, the selection result does not need to be proportional to the magnitude of the switching signal, and the intended selection may be performed according to the purpose.

  The position calculation unit 12 performs necessary calculations such as integration and direction correction from the output of the selection unit 23 to calculate the vehicle position, and outputs the vehicle position.

  The output of the position calculation device of this embodiment is used for applications that require the position of the vehicle, such as navigation devices, safety motion control devices and alarm devices, and travel guidance devices and garage storage devices for convenience. .

  In addition, as a determination of the value of the wobbling degree, for example, the operation of a general driver is measured, and data when there is no wobbling is stored as a predetermined value, and when the wobbling degree calculated from this predetermined value is high, The estimated value and the moving body state may be mixed according to the height and output as a selection result.

  As for mixing, for example, when the height from the predetermined value of the stagger is within the first range, the estimated value is 30%, and the mobile state is 70% by arithmetic mean, and the height from the predetermined value is When it is within the second range higher than the range of 1, the estimated value is 60%, and the mobile body state is 40% mixed by arithmetic mean, and the height from the predetermined value is higher than within the second range May be mixed using the arithmetic average so that the estimated value is 100% and the moving body state is 0%, or may be mixed by another calculation method.

  FIG. 2 is a diagram illustrating a state in which the vehicle performs meandering operation halfway from straight traveling and returns to straight traveling again. The meandering operation is being performed on the way, but the travel trajectory of the vehicle finally travels on the center line 2100 of the straight road.

  FIG. 3 is a flowchart showing the operation of the position calculation apparatus.

  First, the state quantity calculation unit 11 collects measurement values of the internal information measurement unit 10 (step 301). For example, an analog signal from a sensor is measured and taken in as a measured value, or a measured value communicated from a sensor connected to the network is taken in via the network.

  Next, the state quantity calculation unit 11 calculates the state quantity of the vehicle (step 302).

  Here, FIG. 4 shows the acquired value of the steering wheel angle, and FIG. 5 shows the calculated data in the lateral direction G of the vehicle. In the figure, the time 0 to 19 seconds is a straight running, the time 19 to 29 seconds is a meandering operation, and the time 29 to 35 seconds is a straight running. FIG. 6 shows the result of a technique for obtaining the movement distance in the horizontal direction by performing the second-order integration in the horizontal direction G, which is a conventional technique.

  In the prior art, the vehicle position is calculated to move in the horizontal direction even though the actual vehicle is traveling straight between 0 seconds and 19 seconds. The displacement is large. This is because the minute lateral acceleration generated by the wobbling at the time of straight traveling is integrated, resulting in a large displacement as an accumulated error.

  In this paper, in order to avoid this, the following processing is performed without integrating the lateral direction G of the vehicle as it is. First, the measurement value of the internal information measuring unit 10 and the vehicle state quantity are acquired in the memory 21 and stored (step 303). The memory 21 can store a plurality of data. When data is input, the stored old information is erased to make a free space, and new information is stored therein. That is, information from the present to the past for a predetermined time is continuously stored in the memory 21.

  Next, the state estimation unit 22 acquires information from the memory 21 and estimates the state amount of the vehicle (step 304). Here, the determination method of the wobbling from the wobbling determination unit 25 may be acquired, and the calculation method for estimating the state quantity of the vehicle based on the presence or absence of the wobbling may be adjusted. The state estimation unit 22 extracts the transition from the past data and calculates the current value, but the calculation method is not limited. In this embodiment, an average value is calculated using a moving average filter, and this is used as an estimated value of the current value. As a result, the state estimation unit 22 calculates and outputs the lateral direction G, the virtual longitudinal direction G, and the virtual yaw angle of the virtual vehicle.

  Next, the wobbling determination unit 25 determines whether or not there is wobbling from the touch amount of the steering wheel operating angle that is the driving state factor (step 305).

  FIG. 7 is a flowchart showing details of step 305.

  First, the pointer indicating the storage position of the buffer that stores the determination value of the handle operation angle in the wobble determination unit 25 is shifted to empty the area in the buffer where the current time data is stored (step 701). Next, a curve is fitted to the operation angle of the handle using a least square method or the like (step 702). Next, the difference between the fitted curve and the handle operating angle at the current time is calculated (step 703). Next, it is determined whether or not the difference is larger than a predetermined value (step 704). If it is larger, 1 is stored in the buffer (step 705), and if it is smaller, 0 is stored in the buffer (step 706). The data for the past 200 ms in the buffer is referred to (step 707), and it is determined whether or not all are 0 (step 708). If all are 0, there is a wobbling (step 709). It is determined that steering is being performed, and it is determined that there is no wobbling (steering is being performed) (step 710).

  FIG. 8 is a diagram illustrating an example of a change in the operation angle when there is wobbling. The figure shows a curve 82 obtained by fitting the steering wheel operating angle 81 and determination curves 83 and 84 for judging whether or not the difference between the fitting curve and the steering wheel operating angle at the current time is large. In the case of the example shown in FIG. 8, the difference in the handle operating angle is small in all the data in the buffer. Therefore, in this case, it is determined that there is wobbling. On the other hand, in the example shown in FIG. 9, there is data that deviates from the determination curve 54 for determining whether or not another operation angle 51 </ b> B of the handle is large. Therefore, in this case, it is determined that there is no wobbling. FIG. 10 shows an example of the result of determining the wobbling from the operation angle of the handle.

  Next, referring to the output of the wobbling determination unit (step 306), if there is no wobbling, the vehicle state quantity is selected (step 307), and if there is wobbling, the estimated value of the vehicle state quantity is selected (step 307). 308).

  Next, necessary calculations such as integration and direction correction are performed from the selected value, and the vehicle position is calculated and output (step 309). FIG. 11 shows the calculation result of the vehicle position in the case of using a method of switching the calculation by determining whether or not the vehicle is wobbling from the steering wheel operation angle. Compared with the calculation result obtained by the conventional method shown in FIG. 6, it can be calculated that the vehicle is in the straight traveling state during straight traveling, and the traveling locus of the vehicle and the calculation result are in good agreement, so that the calculation accuracy of the vehicle position can be improved. I understand that

  As described above, according to the present embodiment, when calculating the position of the moving body from the information of the internal information measuring unit, the wobbling that is a lateral movement with respect to the moving direction of the moving body that causes the calculation accuracy to deteriorate is detected. If it is staggered, the position of the moving body is calculated based on the estimated value of the state of the moving body. If it is not staggered, the position of the moving body is calculated based on the state amount of the moving body. That is, it is possible to improve the calculation accuracy of the moving body position by separately performing processing for a portion in which the calculation accuracy deteriorates in consideration of the characteristics of the moving body.

  In addition, by calculating the degree of wobbling and mixing the state of the moving body and the estimated value of the state of the moving body according to the degree of wobbling, it is possible to quickly calculate the position during movement that is not wobbling. . Further, by referring to the operation angle of the steering wheel, it is possible to determine the wobbling based on the measurement data at a portion closer to the driver, which is one cause of the wobbling, and to detect the wobbling more accurately. In addition, it is possible to detect the wobbling more accurately by monitoring the driver's condition and changing the criterion for determining whether or not the driver fluctuates depending on the driver's condition. Furthermore, it has a memory for storing the characteristics of the driver, and the fluctuation can be detected more accurately by changing the criteria for determining whether or not the driver is unstable depending on the characteristics of the driver.

  FIG. 12 is a diagram illustrating a configuration of the second position calculation device. Hereinafter, a different part from a 1st Example is demonstrated.

  In the second embodiment, GPS data, camera data, and radar data are measured by the external information measurement unit 30 (external sensor or the like), and these data are input to the position calculation unit 31 from the external information measurement unit 30. . Further, the data from the outside is also input to the wobbling determination unit 25. The output of the position calculation unit 31 from the external information measurement unit is input to the memory 21 and to the position selection unit 33. There is a data selector 32 that monitors the output of the position calculator 12 and the output of the position calculator 31 from the external information measuring unit, and selects probable data. The output of the data selector 32 is used to switch the position selector 33. The signal 33C is input, and the position of the moving body 33A and the position of the moving body 33B from the external information measuring unit are selected according to the signal 33C for switching the data selector and output as the position of the moving body. ing.

  In the second embodiment, the data of the external information measuring unit is input to the wobbling determination unit 25 together with the operating state factor. As a result, when wobbling is determined, for example, it is possible to determine whether or not wobbling in consideration of road conditions (curvature, inclination, etc.), and the accuracy of the determination can be further improved.

  The data of the external information measuring unit is also input to the memory 21. Thereby, the information obtained from the external information measuring unit can be used for the calculation of the state estimator, and the accuracy of the estimated value can be further improved.

  As for the output of the position calculation unit 12 and the output of the position calculation unit 31 from the external information measurement unit, the position selection unit selects the likely data and outputs it as the vehicle position.

  As described above, according to the present embodiment, the information from the external information measurement unit is also monitored as the driving state factor, and thereby the fluctuation can be detected more accurately by changing the criterion for determining whether or not the fluctuation is present.

  FIG. 13 is a diagram illustrating an example in which the position calculation device is mounted on the collision avoidance system. In the present embodiment, the position calculation unit 211 and the external field information calculation unit in the control device 210 are determined from the values of the internal sensor of the handle angle sensor 201, the yaw rate sensor 202, the acceleration sensor 203, the laser sensor 204, and the external sensor of the millimeter wave radar 205. In 212, the position of the vehicle and the position of the obstacle are calculated, and when the possibility of a collision is high, the steering device or the brake device is operated to control the vehicle so as to avoid the collision. A position calculation device is used for the position calculation unit 211 in the control device 210 of this system. The position of the vehicle and the position of the obstacle are handed over to the action determination unit 213, and the necessity of the collision avoidance operation is used for the calculation. When there is a need for a collision avoidance operation, an avoidance command is output, and via the driving support unit 214, the steering control device 231, the brake control device 233, the alarm device 232 are operated to move the steering actuator 234, the brake 235, The vehicle 300 is caused to perform a collision avoidance motion.

  When calculating the position of the vehicle in the operation of the collision avoidance system, the position of the vehicle can be calculated with high accuracy even under a situation where the wobble occurs. Therefore, the calculation accuracy of the collision possibility of the collision avoidance system can be improved, and a more reliable system can be constructed.

  FIG. 14 is a diagram illustrating an example in which the position calculation device is mounted on the GPS navigation device 401. In this embodiment, the external information measuring unit has a GPS 206. The GPS navigation device 401 uses the GPS information processing unit 402 to calculate the vehicle position from the GPS information. In addition, since it becomes difficult to grasp the vehicle position in a place where GPS radio waves do not reach or when the vehicle turns at an intersection, the position of this autonomous navigation that uses the autonomous navigation by the internal information measuring unit 10 is used. A position calculation device is used for the calculation unit 211. The calculated position of the moving body is input to the navigation unit 403 and used as information used for navigation. The display control unit 404 calculates information presented by the driver using the used position information, and the driver is displayed through the display 405. To provide.

  When autonomous navigation is required in the operation of the GPS navigation apparatus, the position of the vehicle can be calculated with high accuracy even under a situation in which wobbling occurs by using the position calculation device. Therefore, the accuracy of the GPS navigation device can be improved, and a more reliable navigation device can be constructed.

The figure which shows the structure of a position calculating apparatus. The figure explaining the driving | running | working state of a vehicle. The figure which shows the processing flow of a mobile body position calculation. The figure which shows an example of the acquired value of a handle | steering-wheel angle. The figure which shows an example of the acquired value of the horizontal direction acceleration of a moving body. The figure which shows an example of the result of the method of calculating | requiring the movement distance of a horizontal direction of a prior art. The figure which shows the detailed process flow which determines the presence or absence of fluctuation. The figure which shows an example of the change of the handle | steering-wheel operating angle in case there exists wandering. The figure which shows an example of the change of a handle | steering-wheel operating angle when there is no wobble. The figure which shows an example of the result of having performed the determination of wandering from a steering wheel operation angle. The figure which shows an example of the calculation result of a mobile body position. The figure which shows the structure of another position calculating apparatus. The figure which shows the structure which mounted the position calculating apparatus in the collision avoidance system. The figure which shows the structure which mounted the position calculating apparatus in the GPS navigation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal information measurement part 11 State quantity calculation part 12 Position calculation part 21 Memory 22 State estimation part 23 Selection part 25 Fluctuation determination part 26 Driving state factor acquisition part 27 Driver characteristic acquisition part

Claims (10)

A state measuring unit for measuring the moving body state
A state quantity calculation unit for calculating a state quantity of the moving body based on the moving body state;
A position calculator for calculating the position of the moving body;
A state estimating unit for calculating an estimated value of the moving body state;
A wobbling determination unit that determines whether or not the moving body is wobbling laterally with respect to the traveling direction;
When the stagger determination unit determines that the moving body is staggered, the estimated value is selected, and when the stagger determination unit determines that the mobile body is not staggered, the state quantity is selected and selected. A position calculation device comprising a selection unit that outputs either one to the position calculation unit. A memory for storing at least one of the mobile object state and the mobile object state quantity;
The position calculation device according to claim 1, wherein the state estimation unit calculates the estimated value based on data stored in the memory. The wobbling determination unit further calculates a wobbling degree of the moving body,
The position calculation device according to claim 1, wherein the selection unit mixes the moving body state and the estimated value based on the degree of wobbling.   The selection unit performs mixing by increasing the ratio of the estimated value when the degree of wobbling is higher than a predetermined value, and mixing by increasing the ratio of the moving body state when the degree of wobbling is lower than the predetermined value. The position calculation device according to claim 3, wherein the mixing result is output to the position calculation unit. An operation state factor acquisition unit for acquiring an operation state factor indicating an index representing the operation state of the mobile body;
The position calculation device according to any one of claims 1 to 4, wherein the wobble determination unit varies a determination criterion as to whether or not the moving body is wobbling based on the driving state factor. An operation state factor acquisition unit for acquiring an operation state factor indicating an index representing the operation state of the mobile body;
5. The position calculation device according to claim 1, wherein the wobble determination unit varies a mixing ratio of the estimated value and the moving body state based on the driving state factor.   The position calculation device according to claim 5 or 6, wherein the driving state factor indicates at least one of an operation angle of a steering wheel, a driver's state, and information from the outside world. A driver characteristic acquisition unit for acquiring the driver characteristics;
The position calculation device according to any one of claims 1 to 4, wherein the wobbling determination unit varies a determination criterion as to whether or not the moving body is wobbling based on characteristics of a driver. A driver characteristic acquisition unit for acquiring the driver characteristics;
The position calculation device according to any one of claims 1 to 4, wherein the stagger determination unit varies a mixing ratio of the estimated value and the moving body state based on a driver's characteristics.   The position calculation device according to claim 8, wherein the driver characteristic indicates a habit of steering operation.

Images