JP4664730B2 - Vehicle fixed position stop automatic control device and vehicle driving support device. - Google Patents

Description

  The present invention relates to a vehicle fixed position stop automatic control device and a vehicle driving support device for stopping a vehicle at a fixed position.

  In the vehicle fixed position stop automatic control device that stops the vehicle at a fixed position, a target pattern that can decelerate the vehicle at a predetermined deceleration and stop at the stop position is created in advance, and the actual vehicle speed follows the target pattern. In this way, the brake control of the vehicle is performed by operating the brake notch.

  The target pattern is the speed for each position of the vehicle. Compare the speed of the target pattern with the actual vehicle speed. If the vehicle speed is high, increase the brake notch. If the vehicle speed is low, decrease the brake notch. Control in the direction. As a result, the actual vehicle speed is caused to follow the target pattern, and the vehicle is stopped at a predetermined stop position.

  Thus, in the conventional vehicle fixed position stop automatic control device, the brake notch is operated so that the actual vehicle speed follows the target pattern, and the brake control of the vehicle is performed. When trying to improve the followability, frequent brake notch switching occurs, resulting in poor riding comfort and unstable control. On the other hand, if priority is given to riding comfort and the followability is weakened, the accuracy of the stop position becomes worse.

Therefore, there is one that can ensure stop accuracy without frequently switching the brake notch (see, for example, Patent Document 1). That is, the predicted speed at the switching time when the vehicle is decelerated according to the brake control plan is compared with the actual vehicle speed at the switching time, and if they are different, the brake control plan is changed to facilitate the actual vehicle deceleration situation. This makes it possible to re-calculate the brake control plan according to the fluctuation of the deceleration, thereby improving the stopping accuracy.
JP 2004-297912 A

  However, if there is a characteristic that the deceleration gradually increases even if the same brake notch is held, as in the case of a mechanical brake using friction, the deceleration used to predict the stop position error should be set appropriately. It is not easy to decide. In such a case, the average deceleration when holding the same brake notch from a certain point to the stop is larger than the instantaneous deceleration of that brake notch at that point, and the value is from a certain point to the stop. It depends on how much the deceleration increases.

  Therefore, if the stop position error is predicted using an instantaneous deceleration at a certain time, the deceleration is evaluated low, so the actual stop position is closer to the prediction. In particular, when the deceleration increasing characteristic is strong, there is a possibility that the target stop position may not be reached even if the control is performed based on the predicted value of the stop position error.

  An object of the present invention is to provide a vehicle fixed position stop automatic control device and a vehicle driving support device capable of accurately predicting a stop position error even when there is an increase characteristic of brake deceleration and ensuring stop accuracy.

  The vehicle fixed position stop automatic control device according to the present invention includes vehicle state data acquisition means for acquiring vehicle state data including the current speed of the vehicle, the current position, and the current brake notch, and reduction of each brake notch in response to a decrease in speed. Brake characteristic data holding section for holding brake characteristic data including speed increase characteristics, deceleration change characteristics of each brake notch according to brake notch switching history, response delay time at the time of brake notch switching, and acquisition of the vehicle state data The deceleration is estimated based on the current speed time series data obtained by the means and the change information of the brake notch, and the deceleration ratio which is the ratio of the estimated deceleration to the deceleration increase characteristic of each brake notch is calculated. Deceleration estimation means, brake characteristic data held in the brake characteristic holding unit, and deceleration estimation Average deceleration calculating means for obtaining an average deceleration when the brake notch is decelerated to the stop based on the deceleration ratio calculated in the stage, and the current vehicle speed and current position input from the vehicle state data acquiring means Based on the data such as the current brake notch and the average deceleration of each brake notch input from the average deceleration calculation means, the predicted value of the stop position error when switching from the current brake notch to another brake notch is calculated. Stop position error calculating means for calculating, and brake control command determining means having an evaluation function for determining a brake control command based on a predicted value of the stop position error at each brake notch calculated by the stop position error calculating means And a brake control command output means for outputting a brake control command determined by the brake control command determination means. And wherein the door.

  The vehicle driving support device of the present invention includes vehicle state data acquisition means for acquiring vehicle state data including the current speed of the vehicle, the current position, and the current brake notch, and deceleration increase characteristics of each brake notch in response to a decrease in speed. A brake characteristic data holding unit for holding brake characteristic data including a change characteristic of deceleration of each brake notch according to a brake notch switching history, a response delay time at the time of brake notch switching, and the vehicle state data acquiring unit. A deceleration for estimating a deceleration based on the time-series data of the current speed and the change information of the brake notch and calculating a deceleration ratio that is a ratio of the estimated deceleration to the deceleration increasing characteristic of each brake notch Calculated by the estimation means, the brake characteristic data held in the brake characteristic holding unit, and the deceleration estimation means Average deceleration calculation means for determining the average deceleration when the brake notch is decelerated to the stop based on the determined deceleration ratio, and the driver operates the brake when stopping the station based on the predicted value of the stop position error It is characterized by providing guidance.

  According to the present invention, even when the deceleration of the vehicle increases with a decrease in the speed, the deceleration can be appropriately evaluated and the stop position error can be predicted with high accuracy. Can be secured.

  Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a block diagram of a vehicle fixed position stop automatic control apparatus according to a first embodiment of the present invention. The current speed of the traveling vehicle 1 is calculated by the speed position calculation unit 4 based on information from the speed detection unit 2 such as a tachometer, and the current position of the traveling vehicle 1 is calculated from the ground element such as a transponder. Is calculated by the speed position calculation unit 4 on the basis of information from the ground element detection unit 3 that detects the above signal. The current speed and current position of the vehicle 1 calculated by the speed position calculation unit 4 are input to the vehicle state data acquisition means 6 in the vehicle fixed position stop automatic control device 5. Further, information on the current brake notch (not shown) is also input to the vehicle state data acquisition means 6.

  The brake characteristic data holding unit 7 holds standard characteristic data of the brake. The standard characteristic data of the brake includes the deceleration increase characteristics of each brake notch according to the vehicle speed decrease, the change characteristics of the deceleration of each brake notch according to the brake notch switching history, and the response delay time when switching the brake notch Etc.

  Although there is no general-purpose model for the deceleration increase characteristic of each brake notch according to the vehicle speed decrease, the tendency is that the deceleration increases according to the speed or the speed decrease amount. When the deceleration increase characteristic is a function of speed, there is an example in which the increase in deceleration is smaller than when the initial speed is high because the decrease in speed until stopping is small when the initial speed is small. Therefore, it is desirable that the model of the deceleration increase characteristic is not a function of speed but a function of speed decrease amount. Thereby, even if the initial speed changes, the deceleration increasing characteristic can be expressed by a single model.

  The change characteristics of the deceleration of each brake notch according to the brake notch switching history may differ when switching from a lower brake notch and when switching from a higher brake notch, even for the same brake notch. The change characteristics of the deceleration of each brake notch according to the brake notch switching history taking into account the brake notch before switching to the brake notch are stored in advance. The response delay time at the time of brake notch switching is a delay time from when the brake notch is operated until a response is made, and this is also stored in the brake characteristic data holding unit 7 in advance.

  The deceleration estimation means 12 estimates the deceleration based on the current speed time series data acquired by the vehicle state data acquisition means 6 and the information on the change of the brake notch, and the deceleration in the deceleration increase characteristic of each brake notch. And a deceleration ratio that is a ratio between the estimated deceleration and the estimated deceleration.

  The deceleration is the rate of change of the speed of the vehicle with respect to time, and is obtained, for example, by obtaining the slope of speed time-series data for 1 second (11 if the speed sampling period is 0.1 seconds) by the least square method or the like. It is done. In this way, by estimating the deceleration based on the slopes of a plurality of time-series data, the deceleration can be accurately evaluated although a delay occurs. It is also possible to obtain a deceleration value by a sensor such as an accelerometer.

  Next, if the deceleration varies depending on the surface condition of the brake, the boarding rate, etc., evaluate whether the actual deceleration is strong or weak against the standard deceleration characteristics of the brake, and based on the evaluation results It is necessary to determine the deceleration used to predict the stop position error. Therefore, a deceleration ratio that is a ratio of the actual deceleration to the standard deceleration characteristic of the brake held in the brake characteristic holding unit 7 is obtained, and the reduction ratio used for prediction of the stop position error is taken into consideration. Determine the speed.

  The obtained deceleration ratio corresponds to a specific brake notch, but if the increase / decrease ratio of deceleration is almost constant regardless of the brake notch, the deceleration ratio is applied to other brake notches as well. It can be applied to predict the stop position error. When a deceleration value is obtained by a sensor such as an accelerometer, the deceleration ratio may be calculated based on the value.

  Here, the deceleration data includes those in the settling state of the brake and those that are not, but when the value in the settling state is set as the standard deceleration characteristic of the brake, the deceleration ratio is It is necessary to calculate only the value in the settling state of the deceleration data. Whether the deceleration data is in a steady state is whether the elapsed time since the switching of the brake notch is equal to or greater than the response time, and the amount of change in deceleration or rate of change from the previous calculation cycle is less than the specified value. Judgment by whether or not.

  When the average slope of the speed time-series data before and after a certain point is used as the deceleration, as in the case of deceleration estimation using the least squares method, the obtained deceleration is at the time corresponding to the center value of the time-series data. It is a past value from the present time. Therefore, whether or not it is in the settling state is also determined based on the past state.

  In addition, as shown in FIG. 2, when the deceleration increases with a decrease in speed, the standard deceleration characteristics of the brake change with the speed. The deceleration ratio is calculated in consideration of whether it is at speed. Further, when the standard deceleration characteristics differ depending on the brake notch history, the brake notch before switching to the brake notch is considered.

  FIG. 3 is a characteristic diagram showing an example of characteristics when the deceleration varies depending on the history of brake notch switching. When the brake notch N is B3 alone, the characteristic curve β (B3) increases as the speed decreases. When the brake notch N is B2 alone, the characteristic increases as the speed decreases. Although it is a curve β (B2), when the brake notch N is switched from B3 to B2, the characteristic curve β (B3 → B2) is obtained, which is different from the characteristic curve β (B2) of B2 alone.

  For example, even if the same brake notch is switched from a lower brake notch, it may be higher when switching from a higher brake notch. When calculating the speed ratio, consider what the brake notch was before switching to the brake notch. That is, the model of the deceleration characteristic corresponding to the brake notch switching history is a model in which a correction coefficient is added for each combination of brake notch switching.

  In this way, by combining the standard model of brake deceleration with the deceleration estimation, the instantaneous deceleration at that time can be appropriately evaluated.

  Next, the average deceleration calculation means 13 is based on the brake characteristic data held in the brake characteristic holding section 7 and the deceleration ratio calculated by the deceleration estimation means 12 when the brake notch is decelerated to stop. The average deceleration is obtained. That is, as shown in FIG. 2, when the deceleration increases with a decrease in speed, if this instantaneous deceleration is used as it is, the deceleration is evaluated at a lower value. The accuracy becomes worse. For this reason, the average deceleration calculating means 13 calculates the average deceleration from the present time to the stop, and predicts the stop position error based on the average deceleration.

  For example, the average deceleration may be calculated directly by calculating the deceleration distance taking into account the deceleration increase characteristics from that point to the stop, and back-calculating from the deceleration distance. In some cases, it is not possible to cope with a short time. Therefore, a simulation is carried out in advance to obtain the ratio of the average deceleration with no increase using the deceleration increase rate from the current time to the stop as a parameter, and the deceleration increase rate and average deceleration coefficient (average deceleration rate) / Momentary deceleration) is created, and the average deceleration is obtained by multiplying the instantaneous deceleration at that time by the average deceleration coefficient corresponding to the deceleration increase rate.

  First, the average deceleration calculating means 13 calculates the deceleration from the present time to the stop based on the brake deceleration increasing characteristics held in the brake characteristic holding section 7 and the current speed inputted from the vehicle state data obtaining means 6. The deceleration increase rate indicating how much increases is obtained. The rate of increase in deceleration is, for example, the ratio of the deceleration to the speed decrease from the start of deceleration at the current time and the ratio of the deceleration to the speed decrease at stop based on the deceleration characteristic equation expressed as a function of the speed decrease amount. It is obtained by calculating. Next, an average deceleration coefficient indicating a ratio between the instantaneous deceleration at that time corresponding to the deceleration increase rate and the average deceleration from that time to the stop is obtained. Then, a relational expression between the deceleration increase rate and the average deceleration coefficient (average deceleration / instantaneous deceleration) is created, and the average deceleration coefficient corresponding to the deceleration increase rate is set as the instantaneous deceleration at that time. Multiply to get the average deceleration.

  FIG. 4 shows the temporal change in speed when the deceleration increases in accordance with the decrease in speed between the present time and the stop. In FIG. 4, a characteristic curve V1 indicates a speed when there is an increase in deceleration, and a characteristic curve V2 indicates a speed when there is no increase in deceleration. The speed integrated by time is the deceleration distance, and the average deceleration βave is obtained from the initial speed Vs and the deceleration distance X using the following relational expression.

βave = Vs ² / 2X
For example, when the deceleration increases by 40% in proportion to the speed decrease, the average deceleration βave is 1.12 times the initial deceleration βs.

  In addition, as the instantaneous deceleration when calculating the average deceleration used for stop position prediction, the deceleration ratio is applied to the standard deceleration characteristics including the deceleration increasing characteristics and the deceleration increasing / decreasing characteristics according to the brake notch switching. Adopt one.

  In this way, by using the average deceleration, it is possible to accurately predict the stop position error even when there is an increase characteristic of the deceleration, and if the brake notch selection is performed based on that, the stop control accuracy can be improved. Can do.

  Next, the stop position error calculation means 8 is an average of each brake notch input from the average deceleration calculation means 13 and data such as the current speed, current position, and current brake notch input from the vehicle state data acquisition means 6. Based on the deceleration data, the stop position error when switching from the current brake notch to each brake notch is calculated taking into account the transient response when switching the brake notch. Considering the transient response, after switching the brake notch, there is a time lag until the deceleration of the brake notch starts to appear, and during the dead time of about 0.3 to 0.5 seconds after switching, This is because the characteristic of the brake notch has come out. In particular, when the number of steps of the brake notch changes greatly before and after switching, if the stop position error is predicted by decelerating at that time by the deceleration of the brake notch after switching, there is a risk that the accuracy of prediction will be reduced.

  The brake control command determining means 9 determines a brake control command based on the predicted stop position error value at each brake notch calculated by the stop position error calculating means 8. Switching of the brake notch based on the brake control command determined by the brake control command determination means 9 is not performed frequently from the viewpoint of ensuring the prediction accuracy of the stop position error, ensuring the deceleration estimation accuracy, and ensuring good riding comfort. It is desirable to do so. For example, frequent brake notch switching can be suppressed by setting the brake notch holding time and not switching the brake notch again until the brake notch holding time elapses after the brake notch switching.

  In actual brake command determination, for example, the lowest brake notch is selected from brake notches whose stop position error does not exceed the target stop position. If the B1 brake notch exceeds the target stop position and the B2 brake notch is one level higher than that, and the B3 brake notch stops before the target stop position, the B2 brake notch is selected. In such a case, after decelerating at the B2 brake notch, it is possible to stop at the target stop position by switching to B1 at an appropriate timing.

  If the current speed is high and the difference in the predicted stop position error between each brake notch is large, the stop position error of the B2 brake notch is almost over the target stop position, and the stop of the B3 brake notch one level above is stopped. In some cases, the position error is much closer to the target stop position. In such a case, if the B3 brake notch is selected, there is a possibility of decelerating too much. Therefore, the brake notch selection is performed in consideration of the deviation of the stop position error of each brake notch with respect to the target stop position.

  For example, after holding the brake notch holding time for B3, a stop position error is predicted when switching to B2 one step below, and the predicted value is on the near side of the allowable range (for example, ± 30 cm) of the stop position. In such a case, B2 is selected even if the stop position error of B2 is over. Immediately before stopping, considering the ride comfort when stopping, select the lowest brake notch as long as it is within the allowable range for the stop position. In order to improve the evaluation function, the evaluation function may be changed according to the speed, for example, if the predicted value is within the allowable range of the stop position (for example, ± 30 cm), the brake notch with the smaller change in brake notch is selected .

  FIG. 5 is an operation characteristic diagram showing an example of the control operation of the vehicle fixed position stop automatic control apparatus according to the first embodiment of the present invention. In FIG. 5A, the vertical axis indicates notches, deceleration, deceleration. FIG. 5 (b) shows the ratio and speed, and the horizontal axis is the remaining distance to the target stop position. In FIG. 5B, the vertical axis is notch, deceleration, deceleration ratio, and speed, and the horizontal axis is time. FIG.

  As shown in FIG. 5, it can be seen from the plot of the change over time of the deceleration that the deceleration varies depending on the speed even with the same brake notch output. The deceleration ratio indicating the ratio of the actual deceleration to the standard brake deceleration characteristic is calculated taking into account the increase characteristic of the deceleration, so the model set on the control side and the actual brake reduction If the speed increase characteristics coincide with each other, the value is almost constant. If the actual brake deceleration increase characteristics are weak, the speed gradually decreases. Thus, even when there is a deceleration increasing characteristic, the control accuracy of the stop position can be secured by selecting an appropriate brake notch.

  Next, the brake control command output means 10 outputs the brake control command determined by the brake control command determination means 9 to the brake device 11 to control the brake device 11. A part or all of the vehicle fixed position stop automatic control device 5 described above may be incorporated in the ATC or ATO.

  As described above, in the vehicle fixed position stop automatic control device 5 according to the first embodiment, even when the deceleration increases as the speed decreases, the deceleration is appropriately evaluated and the stop position error is accurately obtained. Since it can be predicted, the control accuracy of the stop position can be ensured.

  Next, a second embodiment of the present invention will be described. FIG. 6 is a configuration diagram of a vehicle driving support apparatus according to the second embodiment of the present invention. This second embodiment is different from the first embodiment shown in FIG. 1 in that an output device 14 is provided in place of the brake control command determination means 9 and the brake control command output means 10, and the vehicle driving support device and It is a thing. The same elements as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  In FIG. 6, the stop position error calculation means 8 includes data such as the current vehicle speed, current position, and current brake notch input from the vehicle state data acquisition means 6, and each brake input from the average deceleration calculation means 13. Based on the average deceleration of the notch, the predicted value of the stop position error when switching from the current brake notch to another brake notch is calculated. The predicted value of the stop position error calculated by the stop position error calculating means 8 is output to the output device 14. As a result, the driver can know the predicted value of the stop position error, and the driver performs a brake operation. That is, it is possible to support the brake operation by the driver and manually improve the stop position accuracy when the station stops.

The block diagram of the vehicle fixed position stop automatic control apparatus concerning the 1st Embodiment of this invention. The characteristic view which shows an example of the deceleration increase characteristic which deceleration increases according to speed reduction. The characteristic view which shows an example of a characteristic when deceleration changes with the log | history of brake notch switching. The characteristic view which shows an example of the time change of speed when there exists a deceleration increase characteristic which deceleration increases according to speed reduction. The operation characteristic figure which shows an example of control operation of the vehicle fixed position stop automatic control apparatus in the 1st Embodiment of this invention. The block diagram of the vehicle fixed position stop automatic control apparatus concerning the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Speed detection part, 3 ... Ground element detection part, 4 ... Speed position calculation part, 5 ... Vehicle fixed position stop automatic control apparatus, 6 ... Vehicle state data acquisition means, 7 ... Brake characteristic data holding part, 8 ... Stop position error calculation means, 9 ... Brake control command determination means, 10 ... Brake control command output means, 11 ... Brake device, 12 ... Deceleration estimation means, 13 ... Average deceleration calculation means, 14 ... Output device

Claims (7)

Vehicle state data acquisition means for acquiring vehicle state data including the current speed of the vehicle, the current position and the current brake notch;
Brake characteristics holding brake characteristic data including deceleration increase characteristics of each brake notch according to speed reduction, change characteristics of deceleration of each brake notch according to brake notch switching history, response delay time at brake notch switching, etc. A data holding unit;
It is a ratio of the estimated deceleration to the deceleration increasing characteristic of each brake notch, while estimating the deceleration based on the time-series data of the current speed acquired by the vehicle state data acquisition means and the change information of the brake notch Deceleration estimation means for calculating a deceleration ratio;
Average deceleration calculation means for obtaining an average deceleration when the brake notch is decelerated to a stop based on the brake characteristic data held in the brake characteristic holding unit and the deceleration ratio calculated by the deceleration estimation means; ,
Based on the vehicle current speed, current position, current brake notch and other data input from the vehicle state data acquisition means and the average deceleration of each brake notch input from the average deceleration calculation means, the current brake notch Stop position error calculating means for calculating a predicted value of the stop position error when switching from to another brake notch,
Brake control command determination means comprising an evaluation function for determining a brake control command based on the predicted value of the stop position error at each brake notch calculated by the stop position error calculation means;
A vehicle fixed position stop automatic control device, comprising: a brake control command output means for outputting a brake control command determined by the brake control command determination means.   2. The vehicle fixed position stop according to claim 1, wherein the model of the deceleration increase characteristic stored in the brake characteristic data holding unit is a model in which the deceleration is expressed as a function of a speed decrease amount from the start of deceleration. Automatic control device.   2. The vehicle according to claim 1, wherein the model of the deceleration characteristic corresponding to the brake notch switching history stored in the brake characteristic data holding unit is a model in which a correction coefficient is added for each combination of brake notch switching. Fixed position stop automatic control device.   2. The vehicle fixed position stop automatic control according to claim 1, wherein the deceleration estimating means calculates a deceleration based on the inclination based on a plurality of speed time-series data input from the vehicle state data acquiring means. apparatus.   2. The deceleration estimating means extracts a deceleration when the brake is in a set state from the estimated deceleration, and compares the extracted deceleration with a brake deceleration increasing characteristic to calculate a deceleration ratio. Automatic vehicle position stop control device. The average deceleration means is an average deceleration according to a deceleration increase rate which is a ratio of an instantaneous deceleration speed at that time according to a deceleration increase rate from the current time to the stop and an average deceleration from that time to the stop. A speed coefficient is obtained in advance, the deceleration calculated based on the brake deceleration increase characteristic is multiplied by the deceleration ratio obtained by the deceleration estimation means to obtain an instantaneous deceleration, and the average deceleration is calculated as the instantaneous deceleration. 2. The vehicle fixed position stop automatic control device according to claim 1, wherein an average deceleration until stopping is obtained by multiplying by a speed coefficient.
Vehicle state data acquisition means for acquiring vehicle state data including the current speed of the vehicle, the current position and the current brake notch;
Brake characteristics holding brake characteristic data including deceleration increase characteristics of each brake notch according to speed reduction, change characteristics of deceleration of each brake notch according to brake notch switching history, response delay time at brake notch switching, etc. A data holding unit;
It is a ratio of the estimated deceleration to the deceleration increasing characteristic of each brake notch, while estimating the deceleration based on the current speed time series data acquired by the vehicle state data acquisition means and the change information of the brake notch Deceleration estimation means for calculating a deceleration ratio;
Average deceleration calculation means for obtaining an average deceleration when the brake notch is decelerated to a stop based on the brake characteristic data held in the brake characteristic holding unit and the deceleration ratio calculated by the deceleration estimation means; ,
Based on the vehicle current speed, current position, current brake notch and other data input from the vehicle state data acquisition means and the average deceleration of each brake notch input from the average deceleration calculation means, the current brake notch And a stop position error calculating means for calculating a predicted value of the stop position error when the brake is switched to another brake notch, and the driver performs a brake operation guidance when the station stops based on the predicted value of the stop position error A vehicle driving support device.

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