JP2004175148A - Vehicle speed controller and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To let a driver have no sense of incompatibility by bringing the vehicle speed control close to the vehicle speed control at a curve carried out by a general driver. <P>SOLUTION: Respective nodes existing at a front side of the vehicle are detected and stable traveling speed V<SB>T</SB>, i.e., the vehicle speed for stably traveling when the vehicle passes through the respective nodes and a deceleration α<SB>n</SB>required for accelerating/speed-reducing to the stable traveling speed at the nodes until the vehicle arrives at the respective nodes are calculated in order (S110). The point where a value of the speed-reduction degree becomes the largest is selected based on the deceleration α<SB>n</SB>of the respective nodes and the vehicle is speed-reduction controlled such that the speed becomes the stable traveling speed at the point until it arrives at the point (S120-S170). When the point where the curved degree of the curve becomes the largest is different from the point where the previous value of the deceleration becomes the largest and exists at the front side of the vehicle (S180: existing), necessary speed-reduction control is further carried out (S190, S200). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for stably passing a curve or the like of a road by predicting and controlling a stable traveling speed of a vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a technique for reducing a driver's operation burden, for example, in a situation where the speed of the vehicle is desired to be kept constant, such as on an expressway, the vehicle is driven while maintaining the vehicle speed set by the driver. A vehicle speed control device that performs high-speed running control is known. Here, the constant speed traveling control is a control for traveling the vehicle while maintaining the set vehicle speed by controlling an acceleration unit and a deceleration unit for accelerating and decelerating the vehicle.
[0003]
Various proposals have been made to make traveling by such a vehicle speed control device safer. For example, there is a vehicle in which a vehicle speed is controlled such that when traveling on a curve, the vehicle is decelerated to a vehicle speed at which the vehicle can pass through the curve in a stable state (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-2002-96654 (page 4, FIGS. 2, 3, and 4)
[0005]
[Problems to be solved by the invention]
However, when the vehicle speed control as described above is executed, as illustrated in FIG. 11, the vehicle speed can be increased to a speed at which the vehicle can pass through in a stable state before the curve (corresponding to the “curve entrance” in FIG. 11). It may slow down.
[0006]
On the other hand, a general driver controls the vehicle speed as follows when the vehicle approaches a curve. That is, as illustrated in FIG. 2, the driver safely considers the curve in consideration of the available information such as the shape of the curve, the current speed of the vehicle, the road surface condition, the state of the vehicle / curve periphery, and the performance of the vehicle. The vehicle speed and traveling trajectory of the traveling vehicle are predicted quickly, the deceleration required before entering the curve is predicted, and the brake is operated to decelerate. When a vehicle enters a curve, the driver predicts the speed of the vehicle to safely travel on the curve peak, where the curve turns the steepest, and the deceleration required to reach the curve peak And continue running while appropriately adjusting the degree of deceleration by brake operation or the like. When the vehicle passes the curve peak, the driver waits to reach the exit of the curve while maintaining the vehicle speed, and the legal speed of the road and the speed that the driver considers safe when traveling on the next straight road Accelerate the vehicle until.
[0007]
As described above, the vehicle speed control performed by the conventional vehicle speed control device may be different from the vehicle speed control performed by a general driver, and the driver may feel uncomfortable. Also, if there is a following vehicle, as described above, if the vehicle speed control device decelerates to a speed at which the vehicle can pass in a stable state before the curve, the following vehicle may be too close to this vehicle. is there.
[0008]
The present invention has been made in view of such a problem, and an object of the present invention is to realize vehicle speed control that does not cause a driver to feel uncomfortable.
[0009]
Means for Solving the Problems and Effects of the Invention
According to the vehicle speed control device described in claim 1 for solving the above-mentioned problems, according to the position detecting means (5: In this section, in order to facilitate understanding of the invention, the position detecting means (5: , The sign does not mean that the scope of the claims is limited.) Detects the position of the own vehicle, and the vehicle speed detecting means (16) detects the current speed of the own vehicle. I do. Subsequently, the scheduled node detecting means (5) detects one or more nodes scheduled to pass by the vehicle based on the position of the vehicle and the map information in the map information storage means (5). Further, the stable traveling speed calculating means (2) calculates a stable traveling speed which is a vehicle speed for the vehicle to travel stably when passing through the scheduled node. As for the stable running speed, instead of calculating the stable running speed for each node that the vehicle is to pass as described above, the stable running speed calculated for each node on the map in advance is used as the map information storage means. For example, it may be stored and used. Then, the deceleration calculation means (2) calculates the current vehicle speed until the vehicle reaches the scheduled passage node based on the position of the vehicle, the scheduled passage node, the stable traveling speed at the scheduled passage node, and the current speed of the vehicle. The deceleration for decelerating from the speed to the stable traveling speed at the scheduled passage node is calculated. Then, based on the deceleration calculated by the deceleration calculation means, the deceleration target point setting means (2) selects the maximum deceleration node having the largest deceleration among the scheduled passage nodes, and selects the maximum deceleration. A maximum deceleration node is set as a primary deceleration target point which is a target point for deceleration control for the first time after a node is selected, and a stable traveling speed which is farther than the maximum deceleration node among the scheduled passing nodes and Is selected, the deceleration end node is set to a secondary deceleration target point which is a target point when deceleration control is performed for the second time after the maximum deceleration node is selected. . Then, the control means (2) controls the speed reduction means (4) to control the speed of the vehicle so as to reach a stable running speed at the maximum deceleration node before reaching the primary deceleration target point, and further, the primary deceleration. If the target point is different from the secondary deceleration target point, the speed of the vehicle is controlled by controlling the deceleration means so that the vehicle reaches a stable traveling speed at the deceleration end node before reaching the secondary deceleration target point. When the control means controls the vehicle speed toward the primary deceleration target point or the secondary deceleration target point, the control means may decelerate at a constant deceleration. You may make it decelerate gradually.
[0010]
As a result, the vehicle speed control executed by the vehicle speed control device is performed by a general driver as illustrated in FIG. 2, as compared with the conventional vehicle speed control with the deceleration target only at the curve entrance as illustrated in FIG. 11. The deceleration control according to the curve shape is approached, that is, stepwise deceleration control with the deceleration target at the entrance of the curve and at the peak of the curve. Further, if there is a following vehicle, the behavior of the vehicle can be easily predicted by the following vehicle, so that the following vehicle is safer. Therefore, it is possible to realize vehicle speed control that does not give the driver an uncomfortable feeling.
[0011]
After passing through the secondary deceleration target point, the vehicle speed may be controlled so that the vehicle speed is maintained until the vehicle passes through the curve. Further, by providing an acceleration means, the vehicle speed may be controlled so as to accelerate after maintaining the speed of the vehicle for a while. In this case, as the point at which the acceleration is started, as shown in FIG. 7, the vehicle speed obtained by multiplying the stable traveling speed at the secondary deceleration target point by a coefficient (for example, a numerical value larger than 1 such as a numerical value 1.2) (see FIG. 7). Acceleration target vehicle speed V at₂₁(Corresponding to the acceleration start point after the curve in FIG. 7).
[0012]
By the way, when controlling the speed of the vehicle based on the stable running speed at each node, if the vehicle starts decelerating from a distance farther than necessary, the vehicle will run slowly at a reduced speed, which will make the occupant of the vehicle feel uncomfortable. . Therefore, it is conceivable that the control means does not start the deceleration control when the deceleration at the maximum deceleration node is less than a preset value.
[0013]
Here, the “preset value (reference deceleration α in the embodiment)₀Means the maximum value at which the driver of the vehicle, such as the driver, does not feel uncomfortable when the vehicle is decelerated at the deceleration of that value, and may be specified in advance by experiments or the like. . With this configuration, the deceleration is not started from a distance farther than necessary, so that the occupant of the vehicle can drive without feeling uncomfortable.
[0014]
Incidentally, it is conceivable that the above-described detection of the passing point node is performed based on the following criteria. That is, (a) a node existing within a certain range from the current vehicle position, such as a distance from the vehicle position of, for example, 500 m, may be selected from the map information. (B) In addition, when the vehicle decelerates at the reference deceleration, it is conceivable to select a node existing from the current position of the vehicle to a stop point from the map information.
[0015]
Since the nodes of the map information are set at intervals, the point where the deceleration actually becomes largest may be located between the nodes and may not coincide with the maximum deceleration node. Among them, if the point where the deceleration actually becomes the largest is located closer to the front side than the maximum deceleration node, there is a possibility that sufficient deceleration may not be performed until the point where the actual deceleration becomes the largest is reached. . Therefore, it is conceivable that the deceleration target point setting means resets the primary deceleration target point closer to the front than the maximum deceleration node. Here, as a specific example of the position of the reset primary deceleration target point, as illustrated in FIG. 5, the value of the speed of the vehicle is a coefficient (for example, a numerical value 1.2 or the like) of the stable traveling speed at the maximum deceleration node. It is conceivable to reset the above-described primary deceleration target point to a point (a primary deceleration target point in FIG. 5 is equivalent) that is a value obtained by multiplying by a value larger than 1. This increases the possibility that sufficient deceleration is performed until the vehicle actually reaches the point where the deceleration becomes the largest.
[0016]
Also, in the case of the deceleration end node, similarly to the case of the above-described maximum deceleration node, the point where the deceleration should be actually ended may not coincide with the deceleration end node. Therefore, it is conceivable that the deceleration target point setting means re-sets the secondary deceleration target point on the near side of the deceleration end node. This increases the possibility of sufficient deceleration before reaching the point where deceleration actually ends.
[0017]
By the way, if the vehicle is accelerating when executing deceleration control, for example, when there is a curve ahead, deceleration is started after the acceleration is temporarily stopped. Then, since the vehicle was accelerating, the start of deceleration was delayed compared to the case where the vehicle was traveling at a constant speed, and a large deceleration was required until the vehicle reached the primary deceleration target point or the secondary deceleration target point. Will cause discomfort. Therefore, the primary deceleration target point and the secondary deceleration target point are set so that the deceleration target point setting means is equivalent to the traveling distance until the end of the acceleration which is longer than when traveling at a constant speed. Should be reset to the near side. In this way, even if the vehicle is accelerating, the driver does not feel uncomfortable before reaching the primary deceleration target point and the secondary deceleration target point (if different from the primary deceleration target point). Sufficient deceleration can be performed.
[0018]
Further, during execution of the deceleration control, the vehicle may decelerate more than expected due to traffic congestion or the like. In view of the above, an acceleration means for accelerating the vehicle is provided, and the control means is provided when the vehicle speed reaches the stable traveling speed at the maximum deceleration node on the front side of the primary deceleration target point. Stops the deceleration control. On the other hand, when the speed of the vehicle is lower than the stable traveling speed at the maximum deceleration node before the primary deceleration target point, the vehicle controls the acceleration means to control the vehicle. It is possible to control the acceleration. In this way, it is possible to realize vehicle speed control that does not give the driver a feeling of strangeness.
[0019]
Further, as in claim 7, an acceleration means for accelerating the vehicle is provided, and the control means makes the speed of the vehicle reach a stable traveling speed at the deceleration end node between the primary deceleration target point and the acceleration start point. In this case, the deceleration control is stopped to bring the vehicle into a constant speed traveling state. On the other hand, between the primary deceleration target point and the acceleration start point, the vehicle speed is lower than the stable traveling speed at the deceleration end node. When the vehicle speed becomes low, it is conceivable to control the acceleration means to accelerate the vehicle. Here, the "acceleration start point" is a point at which the vehicle starts accelerating ("the acceleration start point after the curve is equivalent, see the embodiment" in Fig. 8). It is possible to realize vehicle speed control that is not required.
[0020]
By the way, the present invention can be configured such that the driver can change at least one of the value of the stable running speed at the primary deceleration target point and the value of the stable running speed at the secondary deceleration target point. Good. As one example, it is conceivable to reset the value by multiplying the value of the stable traveling speed at each point by a coefficient. In this case, the value of the coefficient is set to a value larger than 1 such as a numerical value 1.2 when the vehicle speed is to be increased as a whole, while the coefficient is set to a value larger than 1 when the vehicle speed is to be decreased as a whole. May be set to a numerical value less than 1 such as a numerical value 0.8, for example. With this configuration, the driver can correct the vehicle speed control to his or her favorite vehicle speed, so that the vehicle speed control that does not cause the driver to feel uncomfortable can be realized. In this case, the setting of the coefficient may be configured such that the driver inputs a numerical value, or an option set by the manufacturer to reflect the driver's driving preference (for example, a coefficient numerical value of 0.8, 1.0, 1.2, etc.). Instead of presenting the numerical values of the coefficients, it is desirable to name the soft mode, the normal mode, the sports mode, and the like in ascending order of the numerical values of the coefficients, for example, so that the driver can easily understand. In addition, the setting of the above-described coefficient options may be set in advance when the vehicle speed control device of the present invention is manufactured, or the driver may set the setting if the setting can be changed afterwards. Is also good.
[0021]
The deceleration calculation means, the deceleration target point setting means, the control means, and the stable running speed calculation means in the vehicle speed control device can be realized as a program that causes a computer to function. Therefore, the present invention can be realized as a program invention. In the case of such a program, for example, it is recorded on a computer-readable recording medium such as an FD, an MO, a DVD-ROM, a CD-ROM, and a hard disk, and is used by being loaded into a computer and activated as necessary. be able to. Alternatively, the program may be recorded in a ROM or a backup RAM as a computer-readable recording medium, and the ROM or the backup RAM may be incorporated in a computer.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments to which the present invention is applied will be described with reference to the drawings. It is needless to say that the embodiments of the present invention are not limited to the following examples, and can take various forms within the technical scope of the present invention.
[0023]
FIG. 1 is a block diagram schematically showing a system configuration of a cruise control device to which the above-described invention is applied, and includes an electronic control device for inter-vehicle control (hereinafter, referred to as “inter-vehicle control ECU”) 2 and an engine control. An electronic control unit (hereinafter, referred to as “engine ECU”) 6 and a brake electronic control unit (hereinafter, referred to as “brake ECU”) 4 are mainly configured.
[0024]
[Description of Configuration of Inter-Vehicle Control ECU 2 and the Like]
The inter-vehicle control ECU 2 is an electronic circuit mainly composed of a microcomputer, and includes a current vehicle speed (Vn) signal, a steering angle signal, a yaw rate signal, a target inter-vehicle time signal, wiper switch information, control states of idle control and brake control. Signals and the like are received from the engine ECU 6. The headway control ECU 2 also receives travel path information from a navigation device 5 described later. Further, the following distance control ECU 2 estimates the curve radius of curvature R, calculates the following distance control, and based on the received data, a speed for stably running the vehicle at each node described below (hereinafter referred to as a stable running speed). .), Calculation of deceleration at each node described later, setting of a deceleration target point described later, vehicle speed control, and the like. The inter-vehicle control ECU 2 corresponds to stable running speed calculating means, deceleration calculating means, deceleration target point setting means, and control means.
[0025]
The laser radar sensor 3 is an electronic circuit mainly composed of a scanning distance measuring device using a laser and a microcomputer. The laser radar sensor 3 detects the angle and relative speed of the preceding vehicle detected by the scanning distance measuring device, and the distance control ECU 2. Based on the received current vehicle speed (Vn) signal, curve radius of curvature R, and the like, the own vehicle lane probability of the preceding vehicle is calculated as a part of the inter-vehicle control device, and the inter-vehicle information is calculated as preceding vehicle information including information such as relative speed. Transmit to control ECU2. Further, a diagnosis signal of the laser radar sensor 3 itself is also transmitted to the headway control ECU 2.
[0026]
The scanning range finder scans and irradiates a transmission wave or a laser beam to a predetermined angle range in the vehicle width direction, and determines a distance between the host vehicle and a forward object based on a reflected wave or reflected light from the object. Function as distance measuring means that can be detected in response to
[0027]
Further, the headway control ECU 2 determines a headway vehicle to be headway controlled based on the own lane probability included in the headway information received from the laser radar sensor 3 and appropriately adjusts the headway with the headway vehicle. A target acceleration / deceleration signal, a fuel cut request signal, an OD cut request signal, a third speed shift down request signal, and a brake request signal are transmitted to the engine ECU 6 as control command values. In addition, it determines whether an alarm has occurred and transmits an alarm sounding request signal, or transmits an alarm sounding canceling request signal. Further, it transmits a diagnosis signal, a display data signal, and the like.
[0028]
[Description of Configuration of Navigation Device 5]
The navigation device 5 mainly includes a navigation ECU, a GPS (global positioning system) sensor as a position detection unit, a DVD-ROM as a map information storage unit that records a map database, and the like. The calculated information is output to the inter-vehicle control ECU 2 at regular intervals (every approximately one second in the present embodiment) about the traveling path on which the vehicle is traveling.
[0029]
Here, the information on the travel route includes link information, node information, segment information, link-to-link connection information, and the like, and these are stored in the above-described road database.
As the link information, a "link ID" which is a unique number for specifying the link, a "link class" for identifying, for example, an expressway, a toll road, a general road or an attachment road, and a "starting point" of the link There is information on the link itself such as “coordinates” and “end coordinates” and “link length” indicating the length of the link.
[0030]
The node information includes “node ID” which is a number unique to a node connecting a link, information on node latitude, node longitude, right / left prohibition at an intersection, presence / absence of a traffic light, and the like. The segment information includes information such as a segment ID, a start point (node) latitude (degree), a start point (node) longitude (degree), a segment direction (dir), and a segment length (inter-node distance, len). is there. Note that the values of the starting latitude and the starting longitude include decimal places, and are obtained by converting "minutes" and "seconds" to "degrees". In addition, the direction (dir) of the segment is set such that the true east direction on the map is counterclockwise with respect to the reference (dir = 0), and one unit (dir = 1) is obtained by dividing 360 ° around 360 ° into 1,024. . For example, “dir = 30” indicates a direction rotated counterclockwise (30 × 360/1024) degrees from a eastward direction on the map. In addition, one unit (len = 1) of the length of the segment (distance between nodes, len) is set as an actual 10 cm.
[0031]
In the inter-link connection information, for example, data indicating whether or not traffic is allowed for one-way traffic or the like is set. Even if the links are the same, for example, in the case of one-way traffic, it is possible to pass from one link but not from another link. Therefore, passage or non-passage is determined only by the connection mode between the links.
[0032]
The navigation device 5 corresponds to a passage scheduled node detecting unit.
[Description of Configuration of Brake ECU 4]
The brake ECU 4 is an electronic circuit mainly composed of a microcomputer. The brake ECU 4 obtains a steering angle and a yaw rate from a steering sensor 8 for detecting a steering angle of the vehicle and a yaw rate sensor 10 for detecting a yaw rate. A brake actuator 25 is transmitted to the inter-vehicle control ECU 2 via the ECU 6, and controls a brake actuator 25 for duty-controlling the opening and closing of a pressure-increasing control valve and a pressure-reducing control valve provided in a brake hydraulic circuit for controlling a braking force. Further, the brake ECU 4 sounds the alarm buzzer 14 in response to an alarm request signal from the headway control ECU 2 via the engine ECU 6. Note that the brake ECU 4 corresponds to a deceleration unit.
[0033]
[Description of Configuration of Engine ECU 6]
The engine ECU 6 is an electronic circuit mainly composed of a microcomputer, and includes a throttle opening sensor 15, a vehicle speed sensor 16 as vehicle speed detecting means for detecting the vehicle speed, a brake switch 18 for detecting whether or not a brake is depressed, a cruise switch. Detection signals from the control switch 20, the cruise main switch 22, and other sensors and switches, or wiper switch information and tail switch information received via a known communication line such as a body LAN 28 are received. Further, a steering angle signal and a yaw rate signal from the brake ECU 4, or a target acceleration signal, a fuel cut request signal, an OD cut request signal, a third speed shift down request signal, a warning request signal, a diagnosis signal, and display data from the headway control ECU 2 A signal or the like is being received.
[0034]
Here, the cruise control switch 20 includes a control start switch, a control end switch, an accelerator switch, a coast switch, and the like. The control start switch is a switch for enabling the cruise control to be started. By turning on the control start switch while the main switch is ON, the cruise control can be started. In the cruise control, the inter-vehicle control and the cruise control are selectively executed under predetermined conditions. The accelerator switch is a switch for gradually increasing the stored set vehicle speed by pressing the accelerator switch, and the coast switch is for gradually decreasing the stored set vehicle speed by pressing the accelerator switch. Switch. Further, the inter-vehicle distance between the host vehicle and the preceding vehicle can be set via the cruise control switch 20. The inter-vehicle distance can be set stepwise according to the driver's preference.
[0035]
The engine ECU 6 then controls the throttle actuator 24 for adjusting the throttle opening of the internal combustion engine (here, gasoline engine) and the actuator driving means of the transmission 26 in accordance with the operating state determined from the received signal. Is output. With these actuators, it is possible to control the output, the braking force, or the shift shift of the internal combustion engine. In this embodiment, the transmission 26 is a five-speed automatic transmission, in which the reduction ratio of the fourth speed is set to “1”, and the reduction ratio of the fifth speed is a value smaller than the fourth speed (for example, 0.7). , A so-called 4-speed + overdrive (OD) configuration. Therefore, when the above-described OD cut request signal is output, if the transmission 26 has shifted to the fifth speed (ie, the shift position for overdrive), the transmission 26 shifts down to the fourth speed. When the downshift request signal is output, the transmission 26 shifts down to the third speed when the transmission 26 shifts to the fourth speed. As a result, these downshifts cause a large engine brake, and the vehicle brake is decelerated by the engine brake.
[0036]
Further, the engine ECU 6 transmits necessary display information to a display such as an LCD provided in the meter cluster via the body LAN 28 to display the display information, or displays a current vehicle speed (Vn) signal, a steering angle signal, A yaw rate signal, a target inter-vehicle time signal, a wiper switch information signal, and a control state signal for idle control and brake control are transmitted to the inter-vehicle control ECU 2.
[0037]
[Description of deceleration control processing]
Next, the deceleration control process executed by the above-mentioned headway distance control ECU 2 will be described with reference to the flowchart for explaining the deceleration control process in FIG. 3 and the deceleration control diagrams in FIGS. In FIGS. 4 to 10, the distance L from the current position of the vehicle is set on the horizontal axis, and the speed of the vehicle (denoted as vehicle speed v in the figure) is set on the horizontal axis, and the position of each node and the stability described later are set. Running speed V_TAre plotted, and an approximate curve connecting these plotted points is shown. In the figure, points related to deceleration control, such as a primary deceleration target point described later, are appropriately shown.
[0038]
In the first step 110 (hereinafter, “step” is simply referred to as “S”), the navigation device 5 calculates the position of the vehicle, the vehicle speed sensor 16 detects the current speed of the vehicle, and then the position of the vehicle. From the reference deceleration α₀Stop distance L to the point where the vehicle stops when decelerating at₀(M) is calculated using the following equation (1).
[0039]
L₀= V₀ ²/ 2α₀= V₀ ²/(2×0.784) (1)
V₀: Current speed of vehicle (m / s)
α₀: Reference deceleration (m / s²)
Here, "reference deceleration α₀"" Means a deceleration to such an extent that a driver of the vehicle such as a driver does not feel uncomfortable when the vehicle is decelerated at the deceleration, and may be specified in advance by experiments or the like. In this embodiment, 0.08 G (= 0.784 m / s)²) Is set to Then, as shown in FIG. 4, the navigation device 5 uses the map database to stop the vehicle from the vehicle position to the stop distance L.₀A point ahead, that is, the vehicle is at a reference deceleration α from the current position₀When the vehicle decelerates, a node existing up to the point where the vehicle stops is detected, and information on the node is output to the following distance control ECU 2.
[0040]
Next, a stable traveling speed V which is a speed for traveling stably when the vehicle passes through each node._T, And the deceleration α required to accelerate and decelerate to a stable running speed at each node before the vehicle reaches each node_nAre calculated in order.
Specifically, first, a segment l that connects a reference node, which is one of the detected nodes, and a node in front of the reference node_n-1And a segment l connecting the reference node and a node on the opposite side of the reference node._nIs calculated using the following equation (2) or (2 ′).
[0041]
dθ = (dir_n-Dir_n-1) × 360/1024 (2)
dθ = ｛1024- (dir_n-Dir_n-1)｝ × 360/1024 (2 ′)
dθ: segment l_n-1And segment l_nAngle between (degrees)
dir_n: Segment l_nDirection
dir_n-1: Segment l_n-1Direction
In this case, (dir_n-Dir_n-1) Is smaller than 512, the expression (2) is used, and (dir_n-Dir_n-1If the absolute value of ()) is greater than or equal to 512, equation (2 ′) is used. Also, (dir_n-Dir_n-1If the value of ()) is a negative value, its absolute value will be used in the calculation.
[0042]
Next, the angle dθ is corrected using the following equation (3) for the following reason. That is, a vehicle traveling on a curve travels linearly on a portion corresponding to a segment on the road, and does not turn at the above-mentioned angle dθ at each node. This is because the vehicle travels outside the portion corresponding to the shape while drawing an arc. Note that l_nAnd l_n-1Is the segment l_n, L_n-1Represents the length of In this case, since the length of each segment on the map database is represented using len, a value calculated using the calculation formula len × 0.1 (m) is used here.
[0043]
dθ₁= (L_n/ (L_n-1+ L_n)) × dθ (3)
dθ₁: Segment l_n-1And segment l_nCorrected for the angle dθ between_n-1At the reference node,₁, The lateral movement distance S (m) required to reach the next node position is calculated using the following equation (4).
[0044]
S = 1_n× sindθ₁... (4)
Then, a stable traveling speed V, which is a vehicle speed for stably traveling when the vehicle passes through each node._T(M / s) is calculated for each node using the following equation (5).
V_T= L_n× (N / 2S)^1/2・ ・ ・ ・ ・ (5)
N: specified value (m / s²)
In this embodiment, the specified value N is 0.3 G (= 2.94 m / s).²) Is set to
[0045]
Also, the deceleration α required for the vehicle to accelerate and decelerate to a stable traveling speed at each node before reaching the node_n(M / s²) Is calculated for each node using the following equation (6).
α_n= (V₀ ²-V_T ²) / 2L_T... (6)
L_T: Distance from the current position of the vehicle to the node (m)
In the subsequent S120, as shown in FIG. 5, the deceleration α of each node calculated in S110_n, The node having the largest deceleration value is selected, the node is set as the “primary deceleration target node”, and the stable traveling speed at the primary deceleration target node is set as “the primary deceleration target vehicle speed V”.₁". If there are a plurality of primary deceleration target node candidates, a node closer to the vehicle among them is set as the primary deceleration target node. This “primary deceleration target node” corresponds to the maximum deceleration node.
[0046]
In S130, a primary deceleration target point is set. Note that this primary deceleration target point is a target point for the first time of deceleration control after the node at which the value of the deceleration becomes the largest in S120 is selected. Specifically, as shown in FIG. 5, the primary deceleration target vehicle speed V₁Is multiplied by "target deceleration speed ratio (numerical value 1.2 in this embodiment)".₁₁And Then, the corrected primary deceleration target vehicle speed V in the approximate curve connecting the nodes₁₁Is set as the primary deceleration target point. Note that such setting is performed for the following reason. That is, since the nodes of the map information are set apart from each other, the point where the deceleration actually becomes maximum may not coincide with the position on the road corresponding to the primary deceleration target node. is there.
[0047]
In subsequent S140, it is determined whether or not the vehicle is accelerating. If the vehicle is accelerating (S140: YES), the moving distance L until the acceleration becomes zero is obtained._S(M) is calculated using the following equation (7).
L_S= ΑV₀/Dα...(7)
α: current acceleration of the vehicle (m / s)²)
dα: Maximum acceleration change rate (m / s)³)
Note that the maximum acceleration change rate dα is determined so that the acceleration of the vehicle does not suddenly change. In this embodiment, the maximum acceleration change rate is 1.0 m / s.³Is set to
[0048]
Then, as shown in FIG._S(In FIG. 9, “the deceleration target shift amount during acceleration is equivalent.”) A correction process is performed to move it toward the near side (S145), and the process proceeds to S150. On the other hand, if the vehicle is not accelerating (S140: NO), the process directly proceeds to S150.
[0049]
In S150, it is determined whether or not the value of the deceleration of the primary deceleration target node is equal to or more than the reference deceleration. Here, if the value of the deceleration of the primary deceleration target node is less than the reference deceleration (S150: NO), the vehicle speed control process is canceled and the process returns to S110. On the other hand, if the deceleration of the primary deceleration target node is equal to or greater than the reference deceleration (S150: YES), it is determined that deceleration is necessary, such as the presence of a curve ahead of the vehicle, and the flow shifts to S160.
[0050]
In S160, the corrected primary deceleration target vehicle speed V is obtained before reaching the primary deceleration target point.₁₁The deceleration is calculated so as to decelerate to the maximum speed, and the deceleration is started (see area A in FIG. 8).
In subsequent S170, the corrected primary deceleration target vehicle speed V is obtained until the primary deceleration target point is reached.₁₁(S170: NO), and when the primary deceleration target point is reached (S170: YES), the process proceeds to S180.
[0051]
In S180, as shown in FIG. 7, based on the acceleration / deceleration of each node calculated in the previous S120, a node that ends deceleration and turns into acceleration is selected. If the node is the same as the primary deceleration target node (S180: NO), the node is set as a "secondary deceleration target node", and the process directly proceeds to S210 to maintain the vehicle speed (S210). On the other hand, if the node is not the same as the primary deceleration target node (S180: YES), the node is set as a "secondary deceleration target node" and the stable traveling speed at the secondary deceleration target node is set as "secondary deceleration target vehicle speed". V₂The process proceeds to S190. Note that this secondary deceleration target node is a target point for the second deceleration control after the deceleration of the “primary deceleration target node” is determined to be equal to or greater than the reference deceleration in S130. . The “secondary deceleration target node” corresponds to a deceleration end node and a second deceleration target point.
[0052]
In S190, deceleration is started toward the secondary deceleration target node set in S180 (see area B in FIG. 8), and the process proceeds to S200.
In S200, the secondary deceleration target vehicle speed V is reached before reaching the secondary deceleration target node.₂(S200: NO), and when the vehicle reaches the secondary deceleration target node (S200: YES), the vehicle speed is maintained (S210).
[0053]
In subsequent S220, a post-curve acceleration start point, which is a point where the vehicle starts accelerating after passing through the curve, is set. Specifically, as shown in FIG. 7, the secondary deceleration target vehicle speed V₂Multiplied by the target acceleration speed ratio (numerical value 1.2 in this embodiment).₂₁And Then, the corrected acceleration target vehicle speed V in the approximate curve connecting the nodes₂₁Is set as the acceleration start point after the curve.
[0054]
Then, the vehicle speed is maintained until the vehicle reaches the acceleration start point after the curve (S230: NO, see "constant speed running" in FIG. 2). When the vehicle reaches the acceleration start point after the curve (S230: YES). After the deceleration control, the vehicle is accelerated (S240, see area E in FIG. 8).
[0055]
As described above, each time deceleration control is required, for example, when the vehicle approaches a curve, the cruise control device of the present embodiment sets the primary deceleration target point and the secondary deceleration target node as described above. As a result, stepwise deceleration control is performed with the target of deceleration at the entrance of the curve and at the peak of the curve.
[0056]
As shown in area A of FIG. 8, before the vehicle passes the primary deceleration target point, the speed of the vehicle may be reduced more than necessary due to the influence of a preceding vehicle or traffic jam. In such a case, the deceleration control is stopped, and the acceleration control is performed according to the situation. Specifically, a traveling distance (hereinafter, simply referred to as a traveling distance) L when the vehicle is accelerated at an allowable acceleration for a deceleration release coefficient time._U(M) is calculated using the following equation (8).
[0057]
L_U= V₀k + α_Uk²/2...(8)
α_U: Allowable acceleration (m / s)²)
k: deceleration release coefficient time (s)
Here, the allowable acceleration α_UIs an acceleration at which the driver of the vehicle such as the driver does not feel uncomfortable. In the present embodiment, 0.08 G (= 0.784 m / s)²) Is set to In addition, the deceleration release coefficient time k is a minimum acceleration time at which a driver such as a driver does not feel uncomfortable, and is set to 1.0 s in the present embodiment.
[0058]
Then, as shown in FIG. 10, the primary deceleration point is set to this travel distance L._U(In FIG. 9, the “deceleration release target shift amount” is equivalent.) The position moved forward is set as the deceleration release target point. Stop and perform acceleration control. This prevents the driver from feeling uncomfortable. If the vehicle speed is reduced more than necessary and becomes lower than the secondary deceleration target vehicle speed as described above, the deceleration control is released and the "secondary deceleration target vehicle speed V₂Is controlled.
[0059]
[effect]
As described above, according to the cruise control device of the present embodiment, each of the nodes existing in front of the vehicle is detected, and the stable traveling speed V, which is the vehicle speed for the vehicle to travel stably when passing through each node, is detected._TAnd the deceleration α required for the vehicle to decelerate to a stable running speed at each node before reaching the node_nAre sequentially calculated (S110). And the deceleration α of each node_n, The point at which the value of the deceleration becomes the largest is selected, and the vehicle is decelerated to reach a stable traveling speed at that point until the point is reached (S140 to S170). If the point at which the curve turns the largest is different from the point at which the value of the deceleration is the largest and exists in front of the vehicle (S180: Yes), further necessary deceleration control is performed. (S190, S200). That is, the vehicle speed control by the cruise control device according to the present embodiment approaches the stepwise deceleration control in a curve performed by a general driver. Further, if there is a following vehicle, the behavior of the vehicle can be easily predicted by the following vehicle, so that the following vehicle is safer. Therefore, it is possible to realize vehicle speed control that does not give the driver an uncomfortable feeling.
[0060]
[Another embodiment]
(1) In the cruise control device of the above embodiment, the primary deceleration target point and the secondary deceleration target point are set based on the node information detected by the navigation device 5 from the map database. However, the present invention is not limited to this. The setting may be made based on information received from the laser radar sensor 3 or image information from the image processing device.
(2) In the cruise control device of the above embodiment, the following distance control ECU 2 determines the stable running speed V_TIs calculated for each node, but the navigation device 5 determines that the stable traveling speed V_TIs stored in advance in the map database together with the node information, and the stable traveling speed V_TMay be transmitted to the headway control ECU 2 together with the node information. In addition, the navigation device 5 has a stable running speed V_TMay be calculated. In this way, the following distance control ECU 2 determines that the stable running speed V_TNeed not be calculated each time, the load on the headway control ECU 2 can be reduced. The traveling speed V during traveling_TIs the running speed V_TThe navigation device 5 may store the information together with the corresponding node information. In this way, for example, when the vehicle travels again on a road on which the vehicle has traveled before, the travel speed V at the time of the previous travel is used._TCan be read from the navigation device 5 and used by the inter-vehicle control ECU 2, so that the vehicle can run at the same speed as before.
(3) In the deceleration control process of the embodiment, the headway control ECU 2 controls the vehicle to decelerate at a constant deceleration until the vehicle reaches the primary deceleration target point or the secondary deceleration target node. You may make it decelerate temporarily.
(4) In the deceleration control processing of the above-described embodiment, the navigation device 5 determines that the vehicle has moved from the current position to the reference deceleration α.₀When the vehicle decelerates, the nodes existing up to the point where the vehicle stops are detected, and these nodes are set to the stable traveling speed V._THowever, a node whose distance from the position of the vehicle is within, for example, 500 m may be detected from the map database. In this way, the number of processes is smaller than in the case of the above embodiment, and the burden on the navigation device 5 can be reduced.
(5) In the deceleration control processing of the above-described embodiment, the secondary deceleration target node as the secondary deceleration target point may be reset to the near side. Specifically, similarly to resetting the primary deceleration target point in S140, the secondary deceleration target vehicle speed V₂Is multiplied by the deceleration target speed ratio, and the point having the value in the approximate curve connecting the nodes is reset as the secondary deceleration target point. This increases the possibility of sufficient deceleration before reaching the point where deceleration actually ends.
(6) The stable running speed V at each of the primary deceleration target point, the secondary deceleration target point, and the acceleration start point after the curve set by the following distance control ECU 2._TMay be configured to be changeable by the driver. Specifically, the stable running speed V at each point_TIs multiplied by a coefficient, and the value is calculated as the stable running speed V_TIt is conceivable to set it again. In this case, the value of the coefficient is set to a value larger than 1 such as a numerical value 1.2, for example, when the vehicle speed is to be increased as a whole. What is necessary is just to set it to a numerical value less than 1 such as the numerical value 0.8. With this configuration, the driver can correct the vehicle speed control to his or her favorite vehicle speed, so that the vehicle speed control that does not cause the driver to feel uncomfortable can be realized. In this case, the driver may input a numerical value to be set as a coefficient, or a coefficient option set by the manufacturer to reflect the driver's driving preference (for example, the coefficient numerical value 0. 8, 1.0, 1.2, etc.), and the driver may select one of these options. Instead of presenting the numerical values of the coefficients, it is desirable to name the soft mode, the normal mode, the sports mode, and the like in ascending order of the numerical values of the coefficients, for example, so that the driver can easily understand. The above-mentioned options may be set in advance when the cruise control device of the present embodiment is manufactured, or may be set by the driver if the settings can be changed afterwards. Good.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram illustrating a system configuration of a cruise control device according to an embodiment.
FIG. 2 is a time chart of deceleration control executed by the cruise control device of the embodiment.
FIG. 3 is a flowchart of deceleration control executed by the cruise control device of the embodiment.
FIG. 4 is an explanatory diagram of deceleration control executed by the cruise control device of the embodiment.
FIG. 5 is an explanatory diagram of deceleration control executed by the cruise control device according to the embodiment.
FIG. 6 is an explanatory diagram of deceleration control executed by the cruise control device of the embodiment.
FIG. 7 is an explanatory diagram of deceleration control executed by the cruise control device of the embodiment.
FIG. 8 is an explanatory diagram of deceleration control executed by the cruise control device according to the embodiment.
FIG. 9 is an explanatory diagram of deceleration control executed by the cruise control device of the embodiment.
FIG. 10 is an explanatory diagram of deceleration control executed by the cruise control device of the embodiment.
FIG. 11 is a time chart of deceleration control executed by a conventional cruise control device.
[Explanation of symbols]
2 ... electronic control device for inter-vehicle control (inter-vehicle control ECU), 3 ... laser radar sensor,
4 ... Brake electronic control unit (brake ECU) 5 ... Navigation device
6 ... Electronic control device for engine control (engine ECU)
8 steering sensor, 10 yaw rate sensor, 14 alarm buzzer,
15: throttle opening sensor, 16: vehicle speed sensor, 18: brake switch,
20: cruise control switch, 22: cruise main switch,
24: throttle actuator, 25: brake actuator,
26: Transmission, 28: Body LAN

Claims (9)

Position detecting means for detecting a position where the vehicle exists;
Map information storage means for storing map information including node information;
Based on the position of the vehicle and the map information, passing node detection means for detecting one or more nodes scheduled to pass by the vehicle (hereinafter, referred to as passing nodes);
Stable traveling speed calculating means for calculating a speed (hereinafter, referred to as a stable traveling speed) for stably traveling when the vehicle passes through the scheduled passage node;
Vehicle speed detection means for detecting a current speed of the vehicle,
Based on the position of the vehicle, the scheduled passing node, the stable traveling speed at the scheduled passing node, and the current speed of the vehicle, the passing of the vehicle from the current speed of the vehicle until the vehicle reaches the scheduled passing node. Deceleration calculating means for calculating deceleration for decelerating to a stable traveling speed at the scheduled node (hereinafter, referred to as deceleration);
On the basis of the deceleration calculated by the deceleration calculating means, a node having the largest deceleration (hereinafter, referred to as a maximum deceleration node) is selected from the scheduled passing nodes, and the maximum deceleration node is selected. The maximum deceleration node is set as a target point (hereinafter, referred to as a primary deceleration target point) at the time of deceleration control for the first time from the first deceleration control. A target point (hereinafter, a secondary deceleration target) at the time of performing deceleration control for the second time after selecting a node whose traveling speed is inverted from a decrease to an increase (hereinafter, referred to as a deceleration end node) and selecting the maximum deceleration node. Deceleration target point setting means for setting the deceleration end node to
Deceleration means for decelerating the vehicle,
Controlling the speed of the vehicle so as to attain a stable traveling speed at the maximum deceleration node before reaching the primary deceleration target point by controlling the deceleration means; and further controlling the primary deceleration target point and the secondary deceleration. When the target point is different, control means for controlling the speed of the vehicle so as to control the deceleration means to reach a stable running speed at the deceleration end node before reaching the secondary deceleration target point,
A vehicle speed control device comprising: The vehicle speed control device according to claim 1,
The vehicle speed control device, wherein the control unit does not start deceleration control when the deceleration at the maximum deceleration node is less than a preset value. The vehicle speed control device according to claim 1 or 2,
The vehicle speed control device, wherein the deceleration target point setting means resets the primary deceleration target point before the maximum deceleration node. The vehicle speed control device according to claim 1,
The vehicle speed control device, wherein the deceleration target point setting means resets the secondary deceleration target point before the deceleration end node. The vehicle speed control device according to any one of claims 1 to 4,
When the vehicle is accelerating, the deceleration target point setting means sets the primary deceleration target point and the secondary deceleration by a travel distance that is longer than when the vehicle is traveling at a constant speed due to the acceleration. A vehicle speed control device characterized by resetting a target point to a near side. The vehicle speed control device according to any one of claims 1 to 5,
An acceleration unit for accelerating the vehicle,
The control means stops the deceleration control when the speed of the vehicle has reached the stable traveling speed at the maximum deceleration node on the front side of the primary deceleration target point. When the speed of the vehicle is lower than the stable running speed at the maximum deceleration node on the near side of the target point, the vehicle is accelerated by controlling the acceleration means. Vehicle speed control device. The vehicle speed control device according to any one of claims 1 to 6,
An acceleration unit for accelerating the vehicle,
The control means sets the vehicle speed to a stable traveling speed at the deceleration end node between the primary deceleration target point and a point at which the vehicle starts accelerating (hereinafter, referred to as an acceleration start point). If it has reached, the deceleration control is stopped, while the speed of the vehicle becomes lower than the stable running speed at the deceleration end node between the primary deceleration target point and the acceleration start point. In this case, the vehicle speed control device controls the acceleration means to control the acceleration of the vehicle. The vehicle speed control device according to any one of claims 1 to 7,
A vehicle speed control device wherein a driver can change at least one of a value of a stable traveling speed at the primary deceleration target point and a value of a stable traveling speed at the secondary deceleration target point. A program for causing a computer to function as deceleration calculation means, deceleration target point setting means, control means, and stable running speed calculation means in the vehicle speed control device according to any one of claims 1 to 8.

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