JP2009281737A - Position detecting device for moving body, and vehicle control apparatus using position detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detecting device that measures a relative position with high accuracy and also can prevent integration of an error with the relative position, and to provide a vehicle control apparatus using this position detecting device. <P>SOLUTION: The position detecting device 10 of the moving body includes a receiving antenna 11 which receives GPS signals from a plurality of GPS satellites, a phase difference integrating part 15 which detects the phase of a carrier wave of each GPS signal at each prescribed time from the detection start time and calculates a phase change amount from a detection start time by integrating a phase difference at the prescribed time, and a relative position calculating part 16 which calculates the relative position in relation to a reference position at the detection start time, based on the phase change amount calculated by the phase difference calculating part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a position detection device for a moving body and a vehicle control device using the position detection device.

  A conventional document (Patent Document 1) discloses a position detection device for measuring the motion state of a moving body. In this conventional position detecting device, a GPS signal from a GPS satellite is received, and the moving speed of the moving body is calculated in a predetermined cycle based on the phase change of the carrier wave of the GPS signal. And a relative position is calculated by integrating the moving speed of the moving body for every predetermined period.

Other GPS position detection methods include a single positioning method, a Doppler frequency measurement method, and an RTK-GPS method. In the single positioning method, the Doppler frequency measurement method, etc., the error of the measured position is large, and the accuracy required for vehicle motion control cannot be ensured. In addition, since the RTK-GPS method uses a two-frequency receiver, the price of the position detection device becomes expensive.
JP 2007-57242 A

  In the above-described position detection device of the prior art (Patent Document 1), since the relative position is calculated by integrating the moving speed of the moving body for each predetermined period, the calculated relative position is calculated by integrating the moving speed. The accompanying error will be included. In particular, when the relative position calculation is continued for a long time using the position detection device of the prior art, the integral calculation of the moving speed is repeated many times, so that an error accompanying the integral calculation of the moving speed accumulates at the relative position. Resulting in. Since the relative position calculated in this way has a large error, it is not suitable for, for example, vehicle motion control.

  The present invention has been made to solve the above-described problem, and is capable of measuring a relative position with high accuracy and preventing an error from being accumulated in the relative position, and the position detection. An object is to provide a vehicle control device using the device.

  In order to achieve the above-described object, a moving body position detection device according to the present invention includes a receiving antenna that receives GPS signals from a plurality of GPS satellites, and a phase of a carrier wave of each GPS signal for a predetermined time from a detection start time. By detecting each time and integrating the phase difference for each predetermined time, based on the phase difference integration unit that calculates the phase change amount from the detection start time, and the phase change amount calculated by the phase difference integration unit, A relative position calculation unit that calculates a relative position of the detection start time with respect to a reference position.

  According to the position detection device of the present invention, for each of GPS signals from a plurality of GPS satellites, the phase of the carrier wave of the GPS signal is detected every predetermined time from the detection start time, and the phase difference for each predetermined time is integrated. Thus, the phase change amount from the detection start time is calculated. Then, based on the phase change amount from the detection start time, the relative position with respect to the reference position of the detection start time is calculated. Therefore, a relative position with a small error can be calculated without accumulating errors due to the calculation of the relative position in the calculated relative position.

  In the mobile body position detection apparatus according to the present invention, the phase difference integration unit obtains the phase of the carrier wave of the GPS signal at predetermined intervals from the detection start time and integrates the phase difference at each predetermined time. When the phase difference integrated value exceeds 2π, it is preferable to add 1 to the integer value bias representing the wave number of the carrier wave and subtract 2π from the phase difference integrated value. According to this configuration, when the phase of the carrier wave of the GPS signal is detected every predetermined time from the detection start time, and the phase difference integrated value obtained by integrating the phase difference every predetermined time exceeds 2π, the carrier wave 1 is added to the integer value bias representing the wave number of 2, and 2π is subtracted from the phase difference integrated value. Therefore, the amount of phase change from the detection start time can be suitably calculated using the integer value bias and the phase difference integrated value.

  Further, the vehicle control device according to the present invention includes the above-described position detection device, a wheel speed sensor that detects the wheel rotation speed and calculates the vehicle speed based on the wheel rotation speed, and the vehicle motion so as to suppress the slip state. A position control device that calculates a speed based on a phase difference of a GPS signal carrier every predetermined time, and a vehicle speed and a wheel speed sensor calculated by the position detection device. When the calculated vehicle speed is substantially the same, it is determined that the vehicle is in a grip state where the vehicle grips the road surface, and the vehicle position in the grip state is set as a reference position. The vehicle movement is controlled so as to suppress the slip state of the vehicle by using the relative position with respect to the reference position detected by the detection device.

  According to the vehicle control device according to the present invention, when the vehicle speed calculated based on the phase difference of the GPS signal carrier every predetermined time and the vehicle speed calculated based on the wheel rotation speed substantially match, It is determined that the vehicle is in the grip state where the road surface is gripped, and the vehicle position in the grip state is set as the reference position. By using the relative position with respect to the reference position set in this way, the vehicle motion can be controlled so as to suppress the slip state of the vehicle. For example, a slip state where the vehicle is slipping with respect to the road surface at a relatively low speed (a slip state with a relatively low yaw rate such as a relatively low speed side slip state or a relatively low speed spin state) is detected and the slip state is suppressed. The vehicle motion can be controlled.

  Further, in the vehicle control device according to the present invention, the vehicle motion control unit calculates a target travel locus of the vehicle based on the reference position, and the relative position detected by the position detection device deviates from the target travel locus. It is preferable to determine that the vehicle is in a slip state in which the vehicle slips on the road surface, and to control the vehicle motion so as to suppress the slip state. According to this configuration, the vehicle motion control unit calculates the target travel locus of the vehicle based on the reference position, and when the relative position detected by the position detection device deviates from the target travel locus, the vehicle moves on the road surface. On the other hand, it is determined that the vehicle is slipping and the vehicle motion is controlled so as to suppress the slipping state. Therefore, it is possible to detect a slip state in which the vehicle is slipping with respect to the road surface at a relatively low speed (such as a relatively low-speed side slip state, a relatively low-speed spin state), and to suppress the slip state.

  Further, in the vehicle control device according to the present invention, the vehicle motion control unit calculates a target travel locus of the vehicle based on the reference position, and the relative position detected by the position detection device deviates from the target travel locus. Determining that the vehicle is slipping with respect to the road surface, controlling the vehicle movement so as to suppress the slipping state, and further, after the vehicle transitions from the slipping state to the gripping state, It is preferable to control the vehicle motion to return. According to this configuration, the vehicle motion control unit calculates the target travel locus of the vehicle based on the reference position, and when the relative position detected by the position detection device deviates from the target travel locus, the vehicle moves on the road surface. On the other hand, it is determined that the vehicle is slipping and the vehicle motion is controlled so as to suppress the slipping state. The vehicle motion control unit controls the vehicle motion so that the vehicle returns to the target travel locus after the vehicle transitions from the slip state to the grip state. Therefore, after detecting a slip state (such as a relatively low-speed side slip state or a relatively low-speed spin state) in which the vehicle is slipping at a relatively low speed with respect to the road surface, Can be returned to the target return trajectory.

  Further, in the vehicle control device according to the present invention, the position detection device has at least two reception antennas for receiving GPS signals, and calculates a relative position of each reception antenna with respect to a reference position. Preferably calculates the vehicle traveling direction based on the relative positions of at least two receiving antennas, and determines whether or not the vehicle is in a slip state based on the vehicle traveling direction. According to this configuration, the vehicle motion control unit calculates the vehicle traveling direction based on the relative positions of the at least two receiving antennas, and determines whether the vehicle is in a slip state based on the vehicle traveling direction. Therefore, even when the vehicle is spinning on the target travel locus without deviating from the target travel locus, the spin state of the vehicle can be detected.

  According to the present invention, it is possible to provide a position detection device capable of measuring a relative position with high accuracy and preventing an error from being accumulated in the relative position, and a vehicle control device using the position detection device. Can do.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

(Configuration of position detection device)
FIG. 1 is a block diagram showing a configuration of a GPS speedometer 10 which is a position detection device of the present embodiment. The GPS speedometer 10 includes a GPS antenna 11, an absolute position detection unit 12, a movement speed detection unit 13, a reference position setting unit 14, a phase difference integration unit 15, and a relative position calculation unit 16. Has been.

  The GPS antenna 11 receives a GPS signal transmitted from a GPS satellite. This GPS signal is a signal obtained by modulating time information of an atomic clock mounted on a GPS satellite, orbit information of a GPS satellite, and the like on a carrier wave having a wavelength λ of about 19 cm. The absolute position detection unit 12 is a processing unit that calculates the absolute position of the GPS speedometer 10 based on time information included in the GPS signal. The moving speed detection unit 13 is a processing unit that detects the phase of the carrier wave of the GPS signal every predetermined time and calculates the moving speed of the GPS speedometer 10 based on the phase change of the carrier wave per predetermined time.

  The reference position setting unit 14 is a processing unit that determines and sets a reference position that is used for the arithmetic processing of the GPS speedometer 10. The reference position is a position where the GPS speedometer 10 exists at the position detection start time. The reference position setting unit 14 is configured to set the reference position in response to a command from an external device (for example, the vehicle motion control unit 30, see FIG. 5). The phase difference integrating unit 15 is a processing unit that calculates the phase change amount of the carrier wave of the GPS signal from the position detection start time. That is, the phase difference integrating unit 15 calculates the phase change amount from the detection start time by detecting the phase of the carrier wave of the GPS signal every predetermined time from the detection start time and integrating the phase difference for each predetermined time. To do. The relative position calculation unit 16 is a processing unit that calculates a relative position with respect to the reference position based on the phase change amount calculated by the phase difference integration unit 15.

(Relative position detection principle)
FIG. 2 is a diagram illustrating the principle of relative position detection in the GPS speedometer. FIG. 2 shows a GPS satellite 101, a GPS speedometer 10 _BEFORE before movement, and a GPS speedometer 10 _AFTER after movement. A broken line S indicates an equidistant surface from the GPS satellite 101.

When the GPS speedometer 10 _BEFORE before movement moves to the position of the GPS speedometer 10 _AFTER after movement, the distance between the GPS satellite 101 and the GPS speedometer 10 changes. For this reason, the position according to the moving distance of the GPS speedometer 10 is between the phase of the carrier wave received by the GPS speedometer 10 _BEFORE before movement and the phase of the carrier wave received by the GPS speedometer 10 _AFTER after movement. A phase difference (phase change amount) is generated.

The phase change amount of the carrier wave of the GPS signal consists of a multiple N of 2π and a fraction θ obtained by subtracting a multiple of 2π from the phase difference. A distance difference D from the GPS satellite 101 to the GPS speedometer 10 before and after the movement is obtained by the following equation (1).
D = (N + θ) × λ (1)
here,
N: multiple of 2π of phase difference θ: fraction of phase difference smaller than 2π λ: wavelength of carrier wave (19 cm)

  When a distance difference D from each GPS satellite to the GPS speedometer 10 is calculated for each of a plurality of GPS satellites, and the plurality of distance differences D are applied to a known arithmetic expression, a movement vector (movement) of the GPS speedometer 10 is obtained. Vector consisting of direction and travel distance) can be calculated. This movement vector represents a relative position with respect to the reference position before the movement.

  In the GPS speedometer 10 of the present embodiment, the phase difference integrating unit 15 stores a multiple N of 2π of the phase difference in an integer value bias parameter n, and the fractional θ of the phase difference is a phase difference integrated value. Store in parameter θsum. Then, the relative position calculation unit 15 calculates the relative position by applying the integer value bias n and the phase difference integrated value θsum to the above equation (1). The integer value bias generally means the wave number between the GPS satellite 101 and the GPS speedometer 10, but in this embodiment, the wave number between the GPS satellite 101 and the GPS speedometer 10 before and after movement. Is defined as the amount of change.

(Relative position detection processing of position detection device)
FIG. 3 is a flowchart showing the relative position detection process of the GPS speedometer 10. In this relative position detection process, the GPS speedometer 10 detects a phase change amount for each of GPS signals received from a plurality of GPS satellites, and calculates a relative position based on these phase change amounts.

  For each GPS signal received from a plurality of GPS satellites, the GPS speedometer 10 integrates a parameter n of an integer value bias, parameters θ0, θ1, θ2 indicating the phase of the carrier wave, and the phase of the carrier wave from the detection start time. The parameter θsum indicating the phase difference integrated value obtained in this way is prepared. And the GPS speedometer 10 performs the process demonstrated below about each of several GPS signal.

  At the start of relative position measurement, the GPS speedometer 10 sets the integer value bias n to 0 and initializes the integer value bias n (S301). Next, the GPS speedometer 10 detects the phase of the carrier wave of the GPS signal, and sets the detected phase of the carrier wave to the parameter θ0 (S302, see FIG. 4A). Here, the time when the phase of the carrier wave is detected is the detection start time, and the position where the phase of the carrier wave is detected is the measurement reference position. Note that the phase of the carrier wave detected initially is a value in the range from 0 to 2π.

  Next, the GPS speedometer 10 detects the phase of the carrier wave of the GPS signal after a lapse of a minute time (for example, 100 ms), and sets the detected phase of the carrier wave to the parameter θ1 (S303 to S304, FIG. )reference). Here, the minute time from the phase detection in step 302 to the phase detection in step 304 is a short time in which the phase difference from θ0 to θ1 is surely a value in the range from 0 to π.

Next, the GPS speedometer 10 calculates the phase difference integrated value θsum according to the following formula (2) (S305).
θsum = (θ1−θ0 + 2π) mod 2π (2)
Here, mod is a function for calculating the remainder when dividing. AmodB means the remainder generated when A is divided by B. Therefore, according to the above formula (1), the phase difference between θ0 and θ1 is calculated as a value within the range from 0 to 2π, and is set to the phase difference integrated value θsum.

  Next, the GPS speedometer 10 further detects the phase of the carrier wave from the GPS satellite after elapse of the minute time (for example, 100 ms), and sets the detected phase of the carrier wave to the parameter θ2 (S306 to S307, (See FIG. 4 (a)). Similar to the phase change from step 302 to step 304, the phase difference from step 305 to step 307 is surely a value in the range from 0 to π.

Next, the GPS speedometer 10 adds the phase increment to the phase difference integrated value θsum according to the following equation (3) (S308).
θsum = θsum + (θ2−θ1) (3)
Here, the phase difference integrated value θsum is a value in the range from 0 to 2π in the first calculation of step 308, but is a value in the range from 0 to 2π in the second and subsequent calculations in step 308. In some cases, the value may exceed 2π.

  Next, the GPS speedometer 10 determines whether or not the absolute value of the phase difference integrated value θsum is smaller than 2π (S309). Here, if the GPS speedometer 10 determines that the absolute value of the phase difference integrated value θsum is equal to or greater than 2π, the process proceeds to step 310. On the other hand, if the GPS speedometer 10 determines that the absolute value of the phase difference integrated value θsum is smaller than 2π, the process proceeds to step 311.

When the process proceeds from step 309 to step 310, the GPS speedometer 10 performs the calculations of the following formulas (4) and (5) and updates the parameters n and θsum (FIGS. 4B and 4C). )reference).
n = n + int (θsum / 2π) (4)
θsum = ((θ2−θ0 + 2π + π) mod2π) −π (5)

  In Expression (3), int is a function for rounding down the value of the specified real number below the decimal point to round the specified real number to an integer closer to 0 than this real number. According to the equations (4) and (5), in response to the phase difference from θ0 to θ2 being 2π or more, 1 is added to the integer value bias n, and from the phase difference integrated value θsum. 2π is subtracted to adjust the phase difference integrated value θsum to a value within the range of −π to + π.

  When the process proceeds from step 309 to step 311, the GPS speedometer 10 moves from the point where the process of step 302 is executed to the point where the process of step 307 is executed based on the integer value bias n and the phase difference integrated value θsum. The movement distance (relative position) is calculated. Here, the moving distance calculation method employed by the GPS speedometer 10 is a calculation process using the above mathematical formula (1).

  Next, the GPS speedometer 10 sets the phase θ2 obtained by the above processing to the phase θ1 (S312; see FIG. 4C). By setting the phase θ2 to the phase θ1 in this way, the parameter θ2 becomes empty, so that the phase of the next detected carrier wave can be set to the parameter θ2. Finally, the GPS speedometer 10 returns to the process of step 306 when the calculation of the relative position is continued, and ends the position measurement process when the calculation of the relative position is ended (S313).

  According to the position detection process of the present embodiment, for each of GPS signals from a plurality of GPS satellites, the phase of the GPS signal carrier is detected every predetermined time from the detection start time, and the phase difference for each predetermined time is integrated. By doing this, the amount of phase change from the detection start time is calculated. Then, based on the phase change amount from the detection start time, the relative position with respect to the reference position of the detection start time is calculated. Therefore, a relative position with a small error can be calculated without accumulating errors due to the calculation of the relative position in the calculated relative position.

  In the position detection processing of the prior art, the phase difference of the carrier wave is detected every predetermined time, the velocity vector for every predetermined time is calculated based on the phase difference of the carrier wave, and the calculated velocity vector is integrated to make the relative The position was calculated. However, in this position detection process, an error associated with the calculation of the velocity vector is accumulated at the calculated relative position. For this reason, in the conventional position detection processing, if the relative position is calculated for a long time, the error of the relative position becomes so large that it cannot be ignored (for example, an error of 2 m or more in the position measurement for 3 minutes). It was difficult to use the relative position for vehicle motion control.

  On the other hand, in the position detection process of this embodiment, the velocity vector is not calculated based on the phase difference every minute time, but the phase change from the detection start time is detected by detecting the phase of the carrier wave every minute time. An amount (integer value bias n and phase difference integrated value θsum) is calculated, and a movement vector is calculated in one calculation process based on the phase change amount. Then, the point indicated by the movement vector starting from the reference position at the detection start time is calculated as a relative position. Therefore, according to the position detection process of the present embodiment, the error due to the calculation of the velocity vector is not accumulated at the relative position, so that the relative position can be obtained with high accuracy.

  In particular, the accuracy of the relative position calculated by the position detection process of the present embodiment is enhanced to such an extent that it can be used for vehicle motion control. In order to respond to the slip state of the vehicle during traveling, vehicle control technology has evolved not only to suppress vehicle slip but also to guide the vehicle in a safe direction. In such a vehicle control technology, the relative position of the vehicle during slipping is accurately detected with an accuracy of several centimeters or less with respect to the vehicle reference position in a normal driving state (for example, a state where the wheels grip the road surface). There is a need. According to the position detection process of this embodiment, it is possible to detect the relative position of the vehicle with an accuracy of several centimeters or less, and it is possible to cope with an advanced vehicle control technology.

(Configuration of vehicle control device)
FIG. 5 is a block diagram showing a configuration of the vehicle control device 1 of the present embodiment. The vehicle control device 1 is mounted on a vehicle such as an automobile, and performs control that supports driving of the vehicle. The vehicle control device 1 includes the GPS speedometer (position detection device) 10 described above. In addition, the vehicle control device 1 includes a steering wheel sensor 21, a brake sensor 22, an accelerator sensor 23, a yaw rate sensor 24, a wheel speed sensor 25, a navigation system 27, a vehicle motion control device 30, and a steering control device 32. A steering actuator 33, an acceleration / deceleration control device 35, an engine 36, and a brake actuator 37.

  The handle sensor 21 is a sensor for detecting the operation amount of the handle operated by the driver to steer the wheels. The brake sensor 22 is a sensor for detecting the amount of depression of the brake pedal used by the driver to decelerate the vehicle. The accelerator sensor 23 is a sensor for detecting the amount of depression of an accelerator pedal used by the driver for accelerating the vehicle. The yaw rate sensor 24 is a sensor for detecting the yaw rate acting on the vehicle. The wheel speed sensor 25 is a sensor for detecting the rotational speed of the wheel and calculating the vehicle speed based on the rotational speed of the wheel.

  The navigation system 27 is a device mounted on the vehicle in order to inform the driver of the route to the destination. The navigation system 27 has map data around the vehicle position, and when the destination is specified by the driver, the navigation system 27 displays a route to the destination on a monitor installed in the passenger compartment. The map data of the navigation system 27 includes road shape data, and this road shape data is used for vehicle motion control.

  The GPS speedometer 10 detects the absolute position, moving speed, and relative position of the vehicle, and outputs these detected values to the vehicle motion control unit 30. As described above, the GPS speedometer 10 sets a reference position and sets a relative position with respect to the reference position. Here, the timing at which the GPS speedometer 10 sets the reference position is determined by the vehicle motion control unit 30. That is, when the vehicle motion control unit 30 gives a timing signal to the GPS speedometer 10, the GPS speedometer 10 sets a reference position according to the timing signal and starts calculating a relative position.

  The vehicle motion control device 30 takes in outputs from the plurality of sensors 21 to 25, the navigation system 27, and the GPS speedometer 10, and controls the motion state of the vehicle based on these outputs. In particular, in the present embodiment, the vehicle motion control device 30 controls the motion state of the vehicle so that the slip state of the vehicle is suppressed or the vehicle returns to the target travel locus. The vehicle motion control device 30 gives a steering amount command value to the steering control device 32 and gives an acceleration / deceleration command value to the acceleration / deceleration control device 35 in order to control the motion state of the vehicle.

  The steering control device 32 controls the steering actuator 33 according to the steering amount command value from the vehicle motion control device 30. The steering actuator 33 is an actuator for adjusting the turning angle of the wheel, and applies a turning torque to the wheel so as to assist the driver's steering operation. The steering actuator 33 is configured to be able to adjust the magnitude and direction of the steering torque applied to the wheels. Therefore, the steering control device 32 adjusts the magnitude and direction of the steering torque that the steering actuator 33 applies to the wheels according to the steering amount command value from the vehicle motion control device 30.

  The acceleration / deceleration control device 35 controls an engine (internal combustion engine) 36 and a brake actuator 37 that are driving sources of the vehicle in accordance with the acceleration / deceleration command value from the vehicle motion control device 30. The acceleration / deceleration control device 35 acts on the vehicle according to the acceleration / deceleration command value from the vehicle motion control device 30 when the acceleration / deceleration command value from the vehicle motion control device 30 commands acceleration of the vehicle. The engine 36 for adjusting the driving force to be controlled is controlled. On the other hand, in the case where the acceleration / deceleration command value from the vehicle motion control device 30 commands the deceleration of the vehicle, the acceleration / deceleration control device 35 determines the vehicle according to the acceleration / deceleration command value from the vehicle motion control device 30. The brake actuator 37 for adjusting the braking force acting on the vehicle is controlled.

(First response processing of vehicle control device)
FIG. 6 is a flowchart showing a first response process for a vehicle behavior abnormality (slip state) by the vehicle motion control unit 30. FIG. 7 is a diagram illustrating the vehicle behavior when the first response process is executed by the vehicle motion control unit 30. With reference to FIG. 6 and FIG. 7, the 1st response process by the vehicle motion control part 30 is demonstrated.

  The vehicle motion control unit 30 determines whether the vehicle is in a straight traveling state based on the steering angle detected by the handle sensor 21 (S601). When the absolute value of the steering angle is equal to or less than a preset threshold value (for example, 1 deg), the vehicle motion control unit 30 determines that the vehicle is traveling straight and proceeds to the process of step 602. On the other hand, when the absolute value of the steering angle is larger than the threshold value, the vehicle motion control unit 30 determines that the vehicle is not in a straight traveling state, and repeats the process of step 601.

  Next, the vehicle motion control unit 30 determines whether or not the vehicle is in a straight traveling state based on the yaw rate detected by the yaw rate sensor 24 (S602). When the absolute value of the yaw rate is equal to or less than a preset threshold value (for example, 1 deg / sec), the vehicle motion control unit 30 determines that the vehicle is traveling straight and almost no yaw rate is acting on the vehicle. Proceed to step 603. On the other hand, when the absolute value of the yaw rate is larger than the threshold value, the vehicle motion control unit 30 determines that the vehicle is not moving straight and a large yaw rate is acting on the vehicle, and returns to the process of step 601.

  Next, the vehicle motion control unit 30 is in a state where the wheels grip the road surface based on the difference between the vehicle ground speed calculated based on the wheel speed and the vehicle ground speed calculated by the GPS speedometer 10. It is determined whether or not (S603). When the two ground speeds are substantially the same and the absolute value of the difference between the two ground speeds is equal to or less than a preset threshold value (for example, 0.01 km / h), the vehicle motion control unit 30 It is determined that the road surface is gripped, and the process proceeds to step 604. On the other hand, if the two ground speeds do not substantially match and the absolute value of the difference between the two ground speeds is greater than the threshold value, the vehicle motion control unit 30 determines that the vehicle is not in a state of gripping the road surface. Then, the processing returns to step 601.

Next, when all the conditions of Step 601 to Step 603 are satisfied, the vehicle motion control unit 30 can determine that the wheel grips the road surface and the traveling state of the vehicle is stable. The vehicle position at that time is set as the reference position (S604). Here, the vehicle motion control unit 30 gives the GPS speedometer 10 a timing signal for the GPS speedometer 10 to set the reference position. The GPS speedometer 10 starts calculating the relative position with respect to the reference position from the time when the reference position is set. 7, the position of the vehicle A ₁ just before entering the curved road is set as the reference position.

  Next, the vehicle motion control unit 30 continuously monitors the detection outputs of the handle sensor 21, the brake sensor 22, and the accelerator sensor 23, and thereafter, based on the detection values of the handle sensor 21, the brake sensor 22, and the accelerator sensor 23, A trajectory (target trajectory) that the vehicle is expected to travel in a few seconds is generated (S605). Here, the vehicle motion control unit 30 calculates a target travel locus of the vehicle with reference to the reference position. The vehicle motion control unit 30 also uses road shape data in order to generate a target locus. In FIG. 7, the curve T is the target locus.

  Next, the vehicle motion control unit 30 takes in the relative position calculated by the GPS speedometer 10 (S606). In FIG. 7, the position of the vehicle A2 traveling on the curved road is taken in as a relative position.

  Next, the vehicle motion control unit 30 determines whether or not the vehicle is in a slip state (S607). In other words, the vehicle motion control unit 30 determines whether or not the deviation of the relative position with respect to the target locus is smaller than a preset threshold value (for example, 1 m) (S607). Here, when the deviation of the relative position with respect to the target locus is smaller than the threshold value, the vehicle motion control unit 30 determines that the vehicle is not in a slip state and ends the process. On the other hand, when the deviation of the relative position with respect to the target locus is larger than the above threshold, it is determined that the vehicle is in a slip state, and VSC (Vehicle Stability Control) control, deceleration control, etc. are performed in order to stabilize the behavior of the vehicle. Slip suppression control is executed (S608).

  According to the first handling process described above, when the vehicle speed calculated based on the phase difference of the carrier wave of the GPS signal every predetermined time and the vehicle speed calculated based on the wheel rotation speed substantially match, Is determined to be in a grip state for gripping the road surface, and the vehicle position in the grip state is set as a reference position. By detecting the relative position with respect to the reference position set in this way, it becomes possible to detect the position with high accuracy. Therefore, the slip state in which the vehicle slips on the road surface at a relatively low speed (relatively low speed). A slip state with a small yaw rate such as a side-slip state or a relatively low-speed spin state) can be detected.

  And in the 1st response | compatibility mentioned above, in order to detect a comparatively low-speed slip state, the slip suppression control for suppressing a comparatively low-speed slip state can be performed. In the slip detection technology according to the prior art, since the slip state of the vehicle is determined from the relationship between the steering angle, the vehicle speed, and the yaw rate, a skid state where the speed is lower than the sensor error or a spin state where the speed is lower than the sensor error is detected. It cannot be detected.

(Second response processing of vehicle control device)
FIG. 8 is a flowchart showing a second response process for a vehicle behavior abnormality (slip state) by the vehicle motion control unit 30. FIG. 9 is a diagram illustrating the vehicle behavior when the second response process is executed by the vehicle motion control unit 30. With reference to FIG. 8 and FIG. 9, the 2nd response | compatibility process by the vehicle motion control part 30 is demonstrated.

  The vehicle motion control unit 30 sets a reference position when the vehicle is in a grip state, generates a target locus with reference to the reference position, in the same procedure as the first response process (S601 to S606) described above, A relative position with respect to the reference position is detected (S801, S802, S803). Next, the vehicle motion control unit 30 determines whether or not the vehicle is in a slip state by a method similar to the first response process (S607) described above (S804). Here, when it is determined that the vehicle motion control unit 30 is in the slip state, the vehicle motion control unit 30 executes slip suppression control such as VSC control and deceleration control (S805). On the other hand, the vehicle motion control part 30 complete | finishes a process, when it determines with it not being a slip state.

Next, the vehicle motion control unit 30 determines whether or not the vehicle has shifted from the slip state to the grip state during the execution of the slip suppression control (S806). Here, the vehicle motion control unit 30 proceeds to the process of step 807 when the vehicle shifts to the grip state. On the other hand, if the vehicle remains in the slip state, the vehicle motion control unit 30 continues the slip suppression control (S805). 9, the vehicle motion control unit 30, until the vehicle reaches from the deviation from the target track T in position A _2, continues the slip suppression control.

Next, immediately after the vehicle shifts to the grip state, the vehicle motion control unit 30 uses a slip angle estimation technique that uses an integrated value of the yaw rate that is generally used in an anti-spin function such as VSC. The traveling direction is estimated (S807). Here, the vehicle traveling direction is a direction along the vehicle center line extending in the front-rear direction of the vehicle. In Figure 9, the vehicle moves to the gripping state at the position A _2, the vehicle motion control unit 30 estimates the vehicle travel direction C.

  Next, the vehicle motion control unit 30 determines whether or not the vehicle traveling direction is a direction that reduces the deviation from the target locus (S808). Here, the vehicle motion control unit 30 proceeds to the processing of step 809 when the vehicle traveling direction is a direction to reduce the deviation from the target locus. On the other hand, if the vehicle traveling direction is not a direction that reduces the deviation from the target locus, the vehicle motion control unit 30 proceeds to the process of step 811. In FIG. 9, the vehicle movement control unit 30 proceeds to the process of step 811 because the vehicle traveling direction is not a direction that reduces the deviation from the target locus.

In step 809, the vehicle motion control unit 30 generates a return trajectory extending from the vehicle position to the target trajectory based on information such as the vehicle position and the vehicle traveling direction (S809). In FIG. 9, the vehicle motion control unit 30 generates a return locus O ₁ . Then, the vehicle motion control unit 30 gives a command for guiding the vehicle in the return trajectory direction to the steering control unit 32 (S810). When the steering control unit 32 receives a command from the vehicle motion control unit 30, the steering control unit 32 controls the steering actuator 33 to steer the wheel with a weak torque and to guide the vehicle in the return trajectory direction.

Next, the vehicle motion control unit 30 determines whether or not the vehicle has traveled a preset distance (for example, a distance of several meters) after the vehicle has shifted to the grip state (S808). Here, the preset distance is a distance that sufficiently increases the accuracy of the vehicle slip angle obtained by integrating the yaw rate. In Figure 9, the vehicle when it reaches the position A _3, have a few meters running from position A _2. Here, the vehicle motion control unit 30 proceeds to the process of step 812 when the vehicle travels a preset distance. On the other hand, the vehicle motion control unit 30 continues the weak steering guidance control when the vehicle is not traveling a preset distance (S807 to S810). In Figure 9, but when the process proceeds to step 812, the vehicle is in the position of the position A _3.

In step 812, the vehicle motion control unit 30 recalculates the vehicle traveling direction, and corrects the vehicle traveling direction based on the detection position of the GPS speedometer 10 (S812). Specifically, the vehicle motion control unit 30 determines that the vehicle is gripped in the direction from the position where the vehicle has shifted to the grip state to the detection position of the GPS speedometer 10 (direction D from position A ₂ to position A ₃ in FIG. 9). calculates the angle α formed between a direction from the transition position to the state return path extends (a direction returning trajectory O ₁ extends from the position a ₂ in FIG. 9), and the angle α and the correction angle. Then, the vehicle motion control unit 30 recalculates the vehicle traveling direction, and corrects the vehicle traveling direction by adding the correction angle α. In this way, the vehicle traveling direction can be corrected based on the detection position of the GPS speedometer 10.

The vehicle motion control unit 30 regenerates the return trajectory based on the corrected vehicle traveling direction information (S813). In FIG. 9, the regenerated return trajectory is a trajectory O ₂ extending from the position A ₃ to the target trajectory T. The vehicle motion control unit 30 gives a command for guiding the vehicle in the return trajectory direction to the steering control unit 32 (S814). When the steering control unit 32 receives a command from the vehicle motion control unit 30, the steering control unit 32 controls the steering actuator 33 to steer the wheel with a strong torque and to guide the vehicle in the return trajectory direction.

  According to the second response process described above, when the vehicle speed calculated based on the phase difference of the carrier wave of the GPS signal for each predetermined time and the vehicle speed calculated based on the wheel rotation speed substantially match, Is determined to be in a grip state for gripping the road surface, and the vehicle position in the grip state is set as a reference position. By detecting the relative position with respect to the reference position set in this way, it becomes possible to detect the position with high accuracy. Therefore, the slip state in which the vehicle slips on the road surface at a relatively low speed (relatively low speed). A slip state with a small yaw rate such as a side-slip state or a relatively low-speed spin state) can be detected.

  In the second response process described above, since a relatively low-speed slip state is detected, slip suppression control for suppressing a relatively low-speed slip state can be executed, and further, the vehicle is gripped from the slip state. After the transition to the state, steering guidance control for returning the vehicle to the target locus can be executed. Therefore, after suppressing the slip state of the vehicle, the vehicle can be returned to the target locus.

(Third response processing of vehicle control device)
FIG. 10 is a flowchart showing a third response process for a vehicle behavior abnormality (slip state) by the vehicle motion control unit 30. FIG. 11 is a diagram illustrating the vehicle behavior when the third response process is executed by the vehicle motion control unit 30. With reference to FIG. 10 and FIG. 11, the 3rd response process by the vehicle motion control part 30 is demonstrated.

  In order to execute the third handling process, the vehicle is equipped with two GPS antennas 11A and 11B. One GPS antenna 11A is arranged on the vehicle front side on the vehicle center line. The other GPS antenna 11B is arranged on the vehicle rear side on the vehicle center line. The vehicle motion control unit 30 can detect the direction from the position of the GPS antenna 11B on the rear side of the vehicle to the position of the GPS antenna 11A on the front side of the vehicle as the vehicle traveling direction.

  The vehicle motion control unit 30 sets the reference position when the vehicle is in the grip state in the same procedure as the first corresponding process (S601 to S606) and the second corresponding process (S1001 to S1003) described above. Is used as a reference to generate a target locus, and a relative position with respect to the reference position is detected (S1001, S1002, and S1003). Next, the vehicle motion control unit 30 determines whether or not the vehicle is in a slip state by a method similar to the first response process (S607) and the second response process (S804) described above (S1004). Here, when it is determined that the vehicle motion control unit 30 is in the slip state, the vehicle motion control unit 30 proceeds to the processing after step 805 of the second correspondence processing.

  On the other hand, even when it is determined in step 1004 that the vehicle motion control unit 30 is not in the slip state, the vehicle may actually slip with respect to the road surface. That is, in a situation where the vehicle is spinning while moving along the target trajectory, the vehicle actually slips with respect to the road surface although it is determined in step 1004 that the vehicle is not slipping. In the third response process, the vehicle motion control unit 30 proceeds to the processes after step 1005 in order to deal with such a situation.

  In step 1005, the vehicle motion control unit 30 detects the direction from the relative position of the GPS antenna 11B relative to the reference position to the relative position of the GPS antenna 11A relative to the reference position as the vehicle traveling direction. In FIG. 11, the vehicle motion control unit 30 detects the direction along the straight line C as the vehicle traveling direction.

  Next, the vehicle motion control unit 30 detects the moving direction of the vehicle center of gravity (S1006). For example, the vehicle motion control unit 30 may detect the moving direction of the center position of the two GPS antennas 11A and 11B as the moving direction of the vehicle center of gravity. In FIG. 11, the vehicle motion control unit 30 detects the direction along the straight line E as the moving direction of the vehicle center of gravity.

  Next, the vehicle motion control unit 30 calculates a vehicle slip angle based on the vehicle traveling direction and the gravity center moving direction (S1007). Here, the vehicle slip angle is an angle difference between the vehicle traveling direction and the gravity center moving direction. In FIG. 11, the vehicle motion control unit 30 detects the angle β as the vehicle slip angle.

  Next, the vehicle motion control unit 30 determines whether or not the vehicle slip angle is larger than the maximum slip angle (S1008). Here, the maximum slip angle is a wheel slip angle at which the lateral force generated by the wheel is maximized, for example, an angle of about 25 degrees. The maximum slip angle can be measured in advance using a tire testing machine, and the vehicle motion control unit 30 holds data on the maximum slip angle measured in advance.

  It is impossible in reality that the vehicle is not spinning and the vehicle slip angle is larger than the maximum slip angle. Therefore, in step 1008, when it is determined that the vehicle slip angle is larger than the maximum slip angle, the vehicle motion control unit 30 determines that the vehicle is spinning while moving along the target locus, Slip suppression control such as VSC control and deceleration control is executed, and the slip suppression control is continued until the vehicle enters the grip state (S1009, S1010).

  Then, immediately after the vehicle enters the grip state, the vehicle motion control unit 30 generates a return locus for returning the vehicle to the target locus, and issues a command for guiding the vehicle in the return locus direction. (S1011 and S1012). When the steering control unit 32 receives a command from the vehicle motion control unit 30, the steering control unit 32 controls the steering actuator 33 to steer the wheel with a strong torque and to guide the vehicle in the return trajectory direction. In the third response process, the vehicle traveling direction calculated based on the relative positions of the two GPS antennas is highly accurate. Therefore, unlike the second response process, strong steering guidance control is performed until the accuracy of the vehicle traveling direction increases. There is no need to wait for execution of the steering wheel, and strong steering guidance control can be executed immediately after the vehicle enters the grip state.

  On the other hand, the fact that the vehicle slip angle is smaller than the maximum slip angle is a possible running state of the vehicle. Therefore, in Step 1008, when it is determined that the vehicle slip angle is smaller than the maximum slip angle, the vehicle motion control unit 30 determines that the vehicle is not spinning and ends the third response process.

  According to the third response process described above, the vehicle motion control unit calculates the vehicle traveling direction based on the relative positions of the two GPS antennas, and determines whether the vehicle is in a slip state based on the vehicle traveling direction. judge. Since the relative positions of at least two GPS antennas are highly accurate, the vehicle traveling direction calculated based on these relative positions is also highly accurate. Therefore, the vehicle motion control unit can detect a relatively low-speed spin state of the vehicle based on the vehicle traveling direction.

It is a block diagram which shows the structure of the GPS speedometer which is a position detection apparatus of this embodiment. It is a figure which shows the relative position detection principle of a GPS speedometer. It is a flowchart which shows the relative position detection process of a GPS speedometer. It is a figure for demonstrating the relative position detection process of a GPS speedometer. It is a block diagram which shows the structure of the vehicle control apparatus of this embodiment. It is a flowchart which shows the 1st response process with respect to the vehicle behavior abnormality by a vehicle motion control part. It is a figure which shows a vehicle behavior at the time of a 1st response process being performed by a vehicle motion control part. It is a flowchart which shows the 2nd response process with respect to the vehicle behavior abnormality by a vehicle motion control part. It is a figure which shows a vehicle behavior at the time of a 2nd corresponding | compatible process being performed by a vehicle motion control part. It is a flowchart which shows the 3rd response process with respect to the vehicle behavior abnormality by a vehicle motion control part. It is a figure which shows a vehicle behavior at the time of a 3rd corresponding | compatible process being performed by a vehicle motion control part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus, 10 ... GPS speedometer (position detection apparatus), 11 ... GPS antenna, 12 ... Absolute position detection part, 13 ... Movement speed detection part, 14 ... Reference position setting part, 15 ... Phase difference integration part, DESCRIPTION OF SYMBOLS 16 ... Relative position calculating part, 21 ... Handle sensor, 22 ... Brake sensor, 23 ... Accelerator sensor, 24 ... Yaw rate sensor, 25 ... Wheel speed sensor, 27 ... Navigation system, 30 ... Vehicle motion control part, 32 ... Steering control part 33 ... Acceleration / deceleration control unit, 35 ... Steering actuator, 36 ... Engine, 37 ... Brake actuator.

Claims (6)

A receiving antenna for receiving GPS signals from a plurality of GPS satellites;
A phase difference integrating unit that calculates a phase change amount from the detection start time by detecting the phase of the carrier wave of each GPS signal every predetermined time from the detection start time and integrating the phase difference for each predetermined time;
A relative position calculation unit that calculates a relative position of the detection start time with respect to a reference position based on the phase change amount calculated by the phase difference integration unit;
A position detection apparatus for a moving body, comprising:   The phase difference integrating unit detects the phase of the carrier wave of the GPS signal every predetermined time from the detection start time, and when the phase difference integrated value obtained by integrating the phase difference every predetermined time exceeds 2π, 2. The position detecting apparatus for a moving body according to claim 1, wherein 1 is added to an integer value bias representing a wave number of a carrier wave, and 2π is subtracted from the phase difference integrated value. A position detecting device according to claim 1;
A wheel speed sensor that detects a wheel rotation speed and calculates a vehicle speed based on the wheel rotation speed;
A vehicle motion control unit for controlling the vehicle motion to suppress the slip state;
With
The position detection device calculates a speed based on a phase difference of a GPS signal carrier every predetermined time, and the vehicle speed calculated by the position detection device substantially matches the vehicle speed calculated by the wheel speed sensor. It is determined that the vehicle is in a grip state where the vehicle grips the road surface, and the vehicle position in the grip state is set as the reference position.
The vehicle control device controls the vehicle motion so as to suppress the slip state of the vehicle by using the relative position with respect to the reference position detected by the position detection device.   The vehicle motion control unit calculates a target travel locus of the vehicle based on the reference position, and the vehicle slips with respect to the road surface when the relative position detected by the position detection device deviates from the target travel locus. The vehicle control device according to claim 3, wherein the vehicle control device determines that the vehicle is in a slipping state and controls the vehicle motion so as to suppress the slipping state.   The vehicle motion control unit calculates a target travel locus of the vehicle based on the reference position, and the vehicle slips with respect to the road surface when the relative position detected by the position detection device deviates from the target travel locus. The vehicle motion is controlled so as to suppress the slip state, and the vehicle motion is controlled so that the vehicle returns to the target travel path after the vehicle transitions from the slip state to the grip state. The vehicle control device according to claim 3, wherein: The position detecting device has at least two receiving antennas for receiving GPS signals, and calculates a relative position of each receiving antenna with respect to the reference position.
The vehicle motion control unit calculates a vehicle traveling direction based on a relative position of the at least two receiving antennas, and determines whether the vehicle is in a slip state based on the vehicle traveling direction. The vehicle control device according to any one of claims 3 to 5.

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