JP4462006B2 - Vehicle motion characteristic estimation method, vehicle motion characteristic estimation computer program, and vehicle motion characteristic estimation device - Google Patents

Description

  The present invention relates to a vehicle motion characteristic estimation method, a vehicle motion characteristic estimation computer program, and a vehicle motion characteristic estimation apparatus. In particular, the present invention relates to a vehicle motion characteristic estimation method, a vehicle motion characteristic estimation computer program, and a vehicle motion characteristic estimation device that can obtain more accurate motion characteristics of a running vehicle.

  In the conventional vehicle motion characteristic estimation method, a lateral G sensor or a yaw rate sensor is provided in the vehicle, and the vehicle side slip angle is calculated from the lateral G or yaw rate by detecting the lateral G or yaw rate of the running vehicle. The motion characteristics of the vehicle were estimated. However, even if the same numerical value is detected during traveling by measuring the same position of the vehicle in the lateral G, the vehicle side slip angle varies depending on the traveling state because the center of gravity of the traveling vehicle changes every moment. For this reason, in the conventional vehicle motion characteristic estimation method, a plurality of lateral G sensors are provided, and the lateral G detected by these lateral G sensors is corrected to improve the estimation accuracy of the vehicle side slip angle. For example, in Patent Document 1, two lateral G sensors are provided at different positions, and the lateral G at the center of gravity is estimated from the lateral G detected by the two lateral G sensors and the yaw rate detected by the yaw rate sensor. As a result, the vehicle side slip angle can be accurately estimated even when the position of the center of gravity changes during traveling.

Japanese Patent Laid-Open No. 5-185942

  However, in the conventional vehicle motion characteristic estimation method, the lateral G at the center of gravity is estimated by correcting the lateral G and yaw rate detected by the lateral G sensor and yaw rate sensor fixed to the vehicle. The accuracy of the vehicle side slip angle may be affected by the accuracy. As a result, there is a possibility that the motion characteristics of the vehicle cannot be accurately estimated.

  The present invention has been made in view of the above, and is a vehicle motion characteristic estimation method, a vehicle motion characteristic estimation computer program, and a vehicle motion characteristic estimation capable of estimating a motion characteristic of a running vehicle with high accuracy. An object is to provide an apparatus.

  In order to solve the above-described problems and achieve the object, a vehicle motion characteristic estimation method according to the present invention includes a traveling state detection procedure for detecting a traveling state of a vehicle and the traveling state detected by the traveling state detection procedure. The center of gravity position estimation procedure for estimating the center of gravity position during travel of the vehicle, and the motion state detection means for moving the motion state detection means for detecting the motion state of the vehicle to the center of gravity position estimated by the center of gravity position estimation procedure A center-of-gravity position motion state detection procedure for detecting the motion state of the vehicle at the center-of-gravity position estimated by the center-of-gravity position estimation procedure by the motion state detection means; and the center of gravity detected by the center-of-gravity position motion state detection procedure A motion characteristic estimation procedure for estimating a motion characteristic of the vehicle from the motion state at a position.

  In this invention, the center-of-gravity position of the vehicle is estimated by the center-of-gravity position estimation procedure from the traveling state detected by the traveling-state detection unit, and the movement state detection unit is moved to the center-of-gravity position by the movement state detection unit moving procedure. Further, the motion state at the estimated center of gravity position is detected by the motion state detection means in the center of gravity position motion state detection procedure. Furthermore, since the motion characteristics of the vehicle are estimated from the motion state at the center of gravity position by the motion characteristic estimation procedure, the motion characteristics can be estimated directly from the motion state at the center of gravity position even when the center of gravity position changes every moment. . As a result, the motion characteristics of the running vehicle can be estimated with high accuracy. Moreover, according to the computer program for estimating vehicle motion characteristics according to the present invention, the above-described vehicle motion characteristic estimation method can be realized using a computer.

  The vehicle motion characteristic estimation method according to the present invention includes a travel state detection procedure for detecting a travel state of the vehicle, and a center of gravity for estimating a center of gravity position during travel of the vehicle from the travel state detected by the travel state detection procedure. Among the plurality of motion state detection means for detecting the position of the vehicle and the motion state of the vehicle, the motion state that identifies the motion state detection means located at the position closest to the position of the center of gravity estimated by the center of gravity position estimation procedure A detecting means specifying procedure, and a center of gravity position motion state detecting procedure for detecting the motion state of the vehicle at the center of gravity estimated by the center of gravity position estimating procedure by the motion state detecting means specified by the motion state detecting means specifying procedure; A motion characteristic estimation procedure for estimating a motion characteristic of the vehicle from the motion state at the center of gravity position detected by the gravity center position motion state detection procedure; Characterized in that it contains.

  In the present invention, when the motion state at the center of gravity position is detected by the center-of-gravity position motion state detection procedure, the one closest to the center-of-gravity position is specified among the plurality of motion state detection means by the motion state detection means specifying procedure. . Thereby, the specified motion state detection means is located at the center of gravity position, and the motion state at the center of gravity position can be detected more reliably. As a result, the motion characteristics of the traveling vehicle can be estimated with higher accuracy. Moreover, according to the computer program for estimating vehicle motion characteristics according to the present invention, the above-described vehicle motion characteristic estimation method can be realized using a computer.

  In the vehicle motion characteristic estimation method according to the present invention, a lateral G sensor and a yaw rate sensor are used as the motion state detection means, and the motion characteristic estimated by the motion characteristic estimation procedure is detected by the lateral G sensor. G and the vehicle side slip angle obtained based on the yaw angular velocity detected by the yaw rate sensor.

  In this invention, by using the lateral G sensor and the yaw rate sensor as the motion state detection means, the lateral G and the yaw angular velocity are detected when the motion state at the center of gravity position is detected in the center of gravity position motion state detection procedure. Therefore, it is possible to detect the motion state at the center of gravity more accurately. Further, by calculating the vehicle side slip angle based on the lateral G and the yaw angular velocity detected by the lateral G sensor and the yaw rate sensor in the motion characteristic estimation procedure, the motion characteristic during traveling of the vehicle is expressed by a specific numerical value. be able to. As a result, the motion characteristics of the running vehicle can be estimated with higher accuracy. Moreover, according to the computer program for estimating vehicle motion characteristics according to the present invention, the above-described vehicle motion characteristic estimation method can be realized using a computer.

Further, in the vehicle motion characteristic estimation method according to the present invention, the center of gravity position estimation procedure is such that the distance in the X direction from the static center of gravity position of the vehicle is dx, and the distance in the Y direction from the static center of gravity position of the vehicle. Is set to dy, the center-of-gravity position is estimated from dx and dy obtained by the following equations (1) and (2).
dx = ((Wf1-Wf2) df + (Wr1-Wr2) dr) / 2W (1)
dy = ((Wr1 ′ + Wr2 ′) / W ′ − (Wr1 + Wr2) / W) × L (2)
In the above equations (1) and (2), the dynamic load of the left front wheel is Wf1, the dynamic load of the right front wheel is Wf2, the distance between the front wheel axles is df, and the dynamic load of the left rear wheel is Wr1, The dynamic load of the right rear wheel is Wr2, the distance between the rear wheel axles is dr, the total dynamic load of the vehicle is W, the static load of the left rear wheel is Wr1 ′, and the static load of the right rear wheel is Wr2 ′. The total static load of the vehicle is W ′ and the wheelbase is L.

  In this invention, since the center of gravity position can be estimated more accurately by estimating the center of gravity position from the result calculated by the above-described equation, the motion state of the vehicle at the center of gravity position can be more reliably determined by the motion state detection means. Can be detected. As a result, the motion characteristics of the running vehicle can be estimated with higher accuracy and the motion characteristics can be clearly recognized. Moreover, according to the computer program for estimating vehicle motion characteristics according to the present invention, the above-described vehicle motion characteristic estimation method can be realized using a computer.

  In addition, the vehicle motion characteristic estimation device according to the present invention includes a control device that executes the vehicle motion characteristic estimation computer program.

  According to the present invention, the vehicle motion characteristic estimation device includes a control device that executes the computer program for vehicle motion characteristic estimation, so that when the vehicle motion characteristic estimation device is mounted on a vehicle, the motion of the vehicle that is running The characteristics can be estimated with high accuracy. As a result, the movement state of the vehicle can be grasped, and safety during vehicle traveling can be improved.

  According to another aspect of the present invention, there is provided a vehicle motion characteristic estimation apparatus that outputs the motion characteristic estimated by the motion characteristic estimation procedure of the vehicle motion characteristic estimation method to the driver of the vehicle.

  In this invention, by outputting the motion characteristic estimated by the motion characteristic estimation procedure to the driver of the vehicle, the driver can recognize the motion characteristic estimated by the motion characteristic estimation procedure. As a result, the driver can estimate the motion characteristics of the traveling vehicle with high accuracy. In addition, by estimating the motion characteristics of the traveling vehicle with high accuracy in this way, the driver can grasp the motion state of the vehicle and improve the safety during driving of the vehicle.

  The vehicle motion characteristic estimation method according to the present invention has an effect that the motion characteristic of a running vehicle can be estimated with high accuracy. In addition, the computer program for estimating vehicle motion characteristics according to the present invention has an effect that the vehicle motion characteristic estimation method described above can be realized using a computer. Moreover, the vehicle motion characteristic estimation apparatus according to the present invention has an effect that the motion characteristic of a running vehicle can be estimated with high accuracy.

  Embodiments of a vehicle motion characteristic estimation method and a vehicle motion characteristic estimation apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic diagram of a vehicle on which a first embodiment of a vehicle motion characteristic estimation apparatus to which the present invention is applied is mounted. FIG. 2 is an AA arrow view of FIG. 3 is a BB arrow view of FIG. FIG. 4 is a view taken along the line CC in FIG. In the vehicle motion characteristic estimation apparatus 10 shown in the figure, a vehicle speed sensor 46, a load sensor 50, a lateral G sensor 40 and a yaw rate sensor 41 as motion state detection means are connected to a control unit 45 as a control device. Among these, the load sensor 50 includes a left front wheel load sensor 51, a right front wheel load sensor 52, a left rear wheel load sensor 53, and a right rear wheel load sensor 54, each of which is equipped with the vehicle motion characteristic estimation device 10. The vehicle 1 is provided near the left front wheel 21, the right front wheel 22, the left rear wheel 23, and the right rear wheel 24, and detects the load received by each wheel 20.

  The vehicle speed sensor 46 detects the vehicle speed of the vehicle 1. The vehicle speed sensor 46 may be detected from a speedometer (not shown) installed in the vehicle 1 or a route connected to the speedometer. However, the speed relative to the road surface is detected by an infrared sensor or the like. Sensors that do this are preferred. The lateral G sensor 40 detects lateral G of the vehicle 1 that is traveling, that is, acceleration in the left-right direction of the vehicle 1, and the yaw rate sensor 41 is yaw angular velocity during traveling of the vehicle 1, that is, An angular velocity when the direction of the vehicle 1 changes is detected. The lateral G sensor 40 and the yaw rate sensor 41 are collectively provided at one place, and are formed to be movable together.

  FIG. 5 is a front view of a display monitor provided in the vehicle motion characteristic estimation apparatus of FIG. Further, the vehicle 1 is provided with a display monitor 60 serving as a vehicle motion characteristic output device for displaying a result of estimating a motion characteristic described later, and the result of estimating the motion characteristic by the display monitor 60 is the vehicle 1. Is output to the driver. The display monitor 60 may be anything such as a liquid crystal panel or a light emitting diode panel as long as the display contents can be visually recognized.

  Further, the control unit 45 to which each of the sensors is connected is provided with a storage unit (not shown) and a processing unit (not shown). The storage unit stores a computer program for realizing the estimation method of the vehicle motion characteristic estimation apparatus 10 according to the present invention. Here, the storage unit is a hard disk device, a magneto-optical disk device, a non-volatile memory such as a flash memory (a storage medium that can be read only such as a CD-ROM), or a RAM (Random Access Memory). Such a volatile memory, or a combination thereof.

  Moreover, the said computer program may be what can implement | achieve the estimation method of the vehicle motion characteristic estimation apparatus 10 which concerns on this invention with the combination with the computer program already recorded on the computer system. Further, the present invention is achieved by recording the computer program for realizing the function of the processing unit on a computer-readable recording medium, causing the computer system to read the computer program recorded on the recording medium, and executing it. Such a control method may be executed. The “computer system” here includes an OS and hardware such as peripheral devices.

  The processing unit includes a memory and a CPU. When the motion characteristic of the vehicle 1 is output to the display monitor 60 from the running state or the motion state detected by each of the above sensors, the processing is performed based on the preset procedure of the vehicle motion characteristic estimation method of the present invention. The unit reads the computer program into a memory incorporated in the processing unit and calculates. At that time, the processing unit appropriately stores a numerical value in the middle of the calculation in the storage unit, and retrieves the stored numerical value and executes the calculation. The processing unit may be realized by dedicated hardware instead of the computer program.

  Next, a calculation method related to the position of the center of gravity and the motion characteristics will be described. When the vehicle 1 is stopped, the center of gravity is also stopped, and the center of gravity when the vehicle is stopped is a static center of gravity 30. When the vehicle 1 travels, the center of gravity 31 moves according to the travel state. For example, the center of gravity 31 generally moves backward when the vehicle 1 is accelerated, moves forward when the vehicle is decelerated, moves rightward when turning left, and moves leftward when turning right. For this reason, the load applied to the wheels 20 is also different when the vehicle is stopped and when the vehicle is running. That is, the load on the left rear wheel 23 and the right rear wheel 24 increases when the vehicle 1 is accelerated, the load on the left front wheel 21 and the right front wheel 22 increases when the vehicle is decelerated, and the load on the right front wheel 22 and the right rear wheel 24 when the vehicle turns left. When the vehicle turns to the right, the loads on the left front wheel 21 and the left rear wheel 23 increase. In addition, when turning while accelerating or turning while decelerating, the movement of the center of gravity 31 and the change in the load of the wheel 20 are the same as those during acceleration / deceleration and turning of the vehicle 1 described above. The characteristics are combined.

Thus, the distance from the static gravity center 30 position to the gravity center position when the gravity center 31 moves during vehicle travel will be described. First, let the left-right width direction of the vehicle 1 be the X direction, and the front-rear direction be the Y direction. In this case, the distance in the X direction from the static gravity center 30 position to the gravity center 31 position is defined as dx. The dynamic load of the left front wheel 21 is Wf1, the dynamic load of the right front wheel 22 is Wf2, the distance between the front wheel axles is df, the dynamic load of the left rear wheel 23 is Wr1, and the dynamic load of the right rear wheel 24 is Wr2. The distance between the rear wheel axles is dr, and the total dynamic load of the vehicle 1 is W. Note that W = Wf1 + Wf2 + Wr1 + Wr2. From these loads and distances, a distance dx in the X direction from the static gravity center 30 position to the gravity center 31 position is obtained from the following equation (3).
(Df / 2−dx) Wf1 + (dr / 2−dx) Wr1 = (df / 2 + dx) Wf2 + (dr / 2 + dx) Wr2 (3)

When the above equation (3) is modified, the equation (4) is obtained, and when further transformed, the equation (5) is obtained, and dx becomes the following equation (6).
(Df / 2 × Wf1 + dr / 2 × Wr1) − (Wf1 + Wr1) dx = (df / 2 × Wf2 + dr / 2 × Wr2) + (Wf2 + Wr2) dx (4)
(Wf1 + Wf2 + Wr1 + Wr2) dx = 1/2 (dfWf1 + drWr1-dfWf2-drWr2) (5)
dx = ((Wf1-Wf2) df + (Wr1-Wr2) dr) / 2W (6)

Further, when the distance in the Y direction from the static gravity center 30 position to the gravity center 31 position is dy, the ratio of the static load to the dynamic load is the centroid 31 position shift in the Y direction, that is, dy. Therefore, when the static load of the left rear wheel 23 is Wr1 ′, the static load of the right rear wheel 24 is Wr2 ′, the total static load of the vehicle 1 is W ′, and the wheel base is L, the following formula (7 ). When this equation (7) is transformed, equation (8) is obtained, and the distance dy in the Y direction from the static gravity center 30 position to the gravity center 31 position can be obtained. Accordingly, since the distance dx in the X direction from the position of the static gravity center 30 to the position of the gravity center 31 and the distance dy in the Y direction can be obtained, the position of the gravity center 31 during traveling of the vehicle can be obtained. The total static load W ′ of the vehicle 1 is the sum of the loads received by the wheels 20 when the vehicle 1 is stopped.
dy / L = (Wr1 ′ + Wr2 ′) / W ′ − (Wr1 + Wr2) / W (7)
dy = ((Wr1 ′ + Wr2 ′) / W ′ − (Wr1 + Wr2) / W) × L (8)

When the vehicle 1 is traveling, the motion characteristics of the vehicle 1 vary depending on the traveling time due to various factors such as the weight balance state and road surface condition of the vehicle 1. One of the elements for easily grasping this changing motion characteristic as a numerical value is a vehicle side slip angle. The vehicle side slip angle is an angle at which the vehicle 1 faces the turning direction when turning while the vehicle is running. When the wheel 20 approaches the limit during turning, the wheel 20 starts to skid, so that the angle at which the vehicle 1 is facing with respect to the turning direction changes, and the vehicle side slip angle changes. This vehicle side slip angle is obtained by setting the vehicle side slip angle as β, the initial vehicle side slip angle as β ₀ , the lateral G as α, the vehicle speed as V, and the yaw angular velocity as γ. (9).
β = β ₀ + ∫ (α / V−γ) dt (9)

  Next, the procedure of the vehicle motion characteristic estimation method will be described. FIG. 6 is a flowchart showing a vehicle motion characteristic estimation pattern of the vehicle motion characteristic estimation apparatus of FIG. As described above, when the vehicle 1 provided with each sensor is run, the running state changes from moment to moment. First, the changing traveling state of the vehicle 1 is detected by a traveling state detection procedure. Specifically, the vehicle speed V is detected by the vehicle speed sensor 46, the dynamic load Wf1 of the left front wheel 21 is detected by the left front wheel load sensor 51, and the right front wheel load sensor 52 is detected. The dynamic load Wf2 of the right front wheel 22, the dynamic load Wr1 of the left rear wheel 23 is detected by the left rear wheel load sensor 53, and the dynamic load Wr2 of the right rear wheel 24 is detected by the right rear wheel load sensor 54 (step S1).

  Next, the position of the center of gravity 31 of the traveling vehicle 1 is estimated by the center of gravity position estimation procedure from the detection result of the traveling state detected by the traveling state detection procedure. The estimation method is that the vehicle speed V, the dynamic load Wf1 of the left front wheel 21, the dynamic load Wf2 of the right front wheel 22, the dynamic load Wr1 of the left rear wheel 23, and the dynamic load Wr2 of the right rear wheel 24 are expressed by the above equation (6) and The distance dx in the X direction and the distance dy in the Y direction from the static centroid 30 position to the centroid 31 position are obtained by substituting into equation (8). Thereby, since the distance from the static gravity center 30 position to the gravity center 31 position is known, the gravity center 31 position can be estimated (step S2). The front wheel axle distance df, the rear wheel axle distance dr, the total dynamic load W of the vehicle 1, the static load Wr1 ′ of the left rear wheel 23, and the static load of the right rear wheel 24 used in these equations are Wr2 ′, The total static load W ′ and the wheel base L of the vehicle 1 are input to the storage unit of the control unit 45 in advance.

  Next, in the movement state detection means moving procedure, the movement state detection means, that is, the lateral G sensor 40 and the yaw rate sensor 41 are moved to the position of the center of gravity 31 estimated in the center of gravity position estimation procedure (step S3). Since the lateral G sensor 40 and the yaw rate sensor 41 can be moved to arbitrary positions by an actuator (not shown) such as a motor, the actuator is operated and moved to the position of the center of gravity 31 described above. The lateral G sensor 40 and the yaw rate sensor 41 that have moved to the position of the center of gravity 31 detect the motion state of the vehicle 1 at the position of the center of gravity 31 according to the center of gravity position motion state detection procedure. G, the yaw rate sensor 41 detects the yaw angular velocity at the position of the center of gravity 31 (step S4).

Next, the motion characteristic of the traveling vehicle 1 is estimated by the motion characteristic estimation procedure from the motion state at the center of gravity 31 position detected by the gravity center position motion state detection procedure. That is, based on the lateral G and yaw angular velocity detected by the lateral G sensor 40 and the yaw rate sensor 41, the vehicle side slip angle is estimated as the motion characteristic of the running vehicle 1 (step S5). The estimation method substitutes the initial vehicle side slip angle β ₀ , the lateral Gα, the vehicle speed V, and the yaw angular velocity γ into the above equation (9) to obtain the vehicle side slip angle β. Thereby, since the vehicle side slip angle is known, the motion characteristic of the traveling vehicle 1 can be estimated. The initial vehicle side slip angle β ₀ is an initial value of the estimation procedure by the vehicle motion characteristic estimation method, but the vehicle side slip angle is 0 because the vehicle 1 is stopped at the start of the vehicle motion characteristic estimation method. Therefore, normally, the initial vehicle side slip angle β ₀ = 0.

  Further, in order to transmit the motion characteristics of the running vehicle 1 obtained by these vehicle motion characteristic estimation methods, that is, the vehicle side slip angle, to the driver of the vehicle 1, the vehicle side slip angle is provided in the vehicle. The image is displayed on the display monitor 60 (step S6). As a result, the driver can grasp the current running state of the vehicle 1 by being able to grasp the motion characteristics of the vehicle 1 while traveling. In addition, after estimating the vehicle side slip angle in this manner, it is possible to continuously estimate the motion characteristics of the traveling vehicle 1, that is, the vehicle side slip angle, by returning to the traveling state detection procedure (step S1) again. it can.

  The display monitor 60 is represented by a vehicle side slip angle graph 61 in which the vertical axis is an angle and the horizontal axis is a time axis (see FIG. 5). When the vehicle side slip angle line 62, which is a vehicle side slip angle line displayed on the vehicle side slip angle graph 61, is larger than 0 °, the state in which the rear wheel starts to slide sideways, that is, the oversteer state is set. In the case where the vehicle side slip angle line is smaller than 0 °, the front wheels are starting to slide sideways. In the vehicle side slip angle graph 61 displayed in this way, the vehicle side slip angle obtained by the vehicle motion characteristic estimation method is displayed as a vehicle side slip angle line 62 as needed, and the end of the vehicle side slip angle line 62 is displayed. Represents the current vehicle side slip angle.

  Further, the range of + 2 ° to −2 ° of the vehicle side slip angle graph 61 is a safety range 63, and this range is displayed with a green background on the screen of the display monitor 60. Further, the range of + 2 ° to + 3 ° and −2 ° to −3 ° of the vehicle side slip angle graph 61 is a caution range 64, and this range is displayed with a yellow background on the screen of the display monitor 60. ing. Further, the range of + 3 ° to + 5 ° and −3 ° to −5 ° of the vehicle side slip angle graph 61 is a dangerous range 65, and this range is displayed with a red background on the screen of the display monitor 60. ing. As described above, in the vehicle side slip angle graph 61 of the display monitor 60, the vehicle side slip angle is displayed in different colors for each range as it is more dangerous as the vehicle side slip angle moves away from 0 °. Even in the motion characteristics, the farther the vehicle side slip angle is from 0 °, the easier it is for the front wheels or rear wheels to slide sideways, making driving difficult. For this reason, when the vehicle side slip angle line 62 enters the caution range 64 or the danger range 65 during traveling, the driver of the vehicle 1 must be aware of the motion state of the vehicle 1 or may be dangerous. Can be estimated. The safety range 63, the caution range 64, and the danger range 65 displayed on the display monitor 60 can be freely set according to the vehicle side slip angle other than the above range.

  The above-described vehicle motion characteristic estimation device 10 estimates the position of the center of gravity 31 from the running state detected by the vehicle speed sensor 46 and the load sensor 50 provided on each wheel 20 (step S2), and sets the lateral G sensor 40 and the yaw rate sensor 41. It has moved to the center of gravity 31 position (step S3). The lateral G sensor 40 and the yaw rate sensor 41 thus detect the lateral G and yaw angular velocity at the position of the center of gravity 31 (step S4). The motion characteristics of the vehicle 1 can be estimated with higher accuracy when estimated from the motion state at the position of the center of gravity 31 that changes during traveling. In this way, the position of the center of gravity 31 of the traveling vehicle 1 is estimated, By moving the lateral G sensor 40 and the yaw rate sensor 41 to the changing center of gravity 31 position, the motion characteristics can be estimated directly from the motion state at the center of gravity 31 position. As a result, the motion characteristics of the traveling vehicle 1 can be estimated with high accuracy.

  Further, when estimating the position of the center of gravity 31 from the detection result by the vehicle speed sensor 46 or the like, the center of gravity 31 of the vehicle 1 that is traveling is more accurately obtained by obtaining and estimating the distance from the position of the static center of gravity 30 by the above-described equation. The position can be estimated. Further, when estimating the motion characteristics of the vehicle 1 that is running, the motion characteristics are estimated by the vehicle side slip angle, and the vehicle side slip angle is calculated from the detection results of the lateral G sensor 40 and the yaw rate sensor 41 according to the above-described formula. By estimating, the motion characteristics while the vehicle is traveling can be expressed by specific numerical values. As a result, the motion characteristics of the running vehicle 1 can be estimated with higher accuracy and the motion characteristics can be clearly recognized.

  Further, by using the lateral G sensor 40 and the yaw rate sensor 41 as the motion state detection means, the lateral G and yaw angular velocities at the center of gravity 31 position can be detected, so the motion state at the center of gravity 31 position can be detected more accurately. can do. As a result, the motion characteristics of the traveling vehicle 1 can be estimated more accurately and with high accuracy.

  Further, by outputting the vehicle side slip angle obtained by the above-described vehicle motion characteristic estimation method to the display monitor 60 provided in the vehicle, the vehicle side slip angle can be output to the driver driving the vehicle 1. Thereby, the driver | operator can recognize the vehicle side slip angle of the vehicle 1 in the driving | running | working estimated with a motion characteristic estimation procedure. As a result, the driver can estimate the motion characteristics of the traveling vehicle 1 with high accuracy. Further, by estimating the motion characteristics of the traveling vehicle 1 with high accuracy in this way, the driver can grasp the motion state of the vehicle 1 and can improve the safety during driving of the vehicle.

  In addition, since the safety range 63 and the like of the display monitor 60 can be freely changed, the safety range 63, the caution range 64, The danger range 65 can be matched to the actual situation of the vehicle 1 that is traveling. As a result, the actual risk level of the traveling vehicle 1 and the risk level recognized by the driver through the display monitor 60 can be matched. As a result, the safety during driving of the vehicle can be further improved.

  This vehicle motion characteristic estimation apparatus has the same configuration as that of the vehicle motion characteristic estimation apparatus according to the first embodiment, but is characterized in that a plurality of lateral G sensors and yaw rate sensors each serving as motion state detection means are provided. Since other configurations are the same as those of the first embodiment, the description thereof is omitted and the same reference numerals are given. FIG. 7 is a schematic diagram of a vehicle on which a second embodiment of the vehicle motion characteristic estimation apparatus to which the present invention is applied is mounted. The vehicle motion characteristic estimation device 80 shown in the figure is provided with a plurality of lateral G sensors 40 and yaw rate sensors 41 serving as motion state detection means. The position is provided around the position of the static gravity center 30 of the vehicle 1 in which the vehicle motion characteristic estimation device 80 is provided, and when the gravity center 31 that moves when the vehicle 70 travels moves most. They are arranged in a range including the estimated center of gravity 31 position.

  Next, the procedure of the vehicle motion characteristic estimation method of the vehicle motion characteristic estimation apparatus according to the second embodiment will be described. FIG. 8 is a flowchart showing a vehicle motion characteristic estimation pattern of the vehicle motion characteristic estimation apparatus of FIG. The vehicle motion characteristic estimation method of the vehicle motion characteristic estimation apparatus 80 according to the second embodiment is similar to the vehicle motion characteristic estimation method of the vehicle motion characteristic estimation apparatus 10 according to the first embodiment. Alternatively, the vehicle speed V and the dynamic load of each wheel 20 are detected by the load sensor 50 provided on each wheel 20 of the vehicle 70, thereby detecting the traveling state of the vehicle 70 (step S11).

  Next, in the center-of-gravity position estimation procedure, the distance dx in the X direction from the static center of gravity 30 position to the center of gravity 31 position based on the traveling state of the vehicle 70 detected by the vehicle speed sensor 46 and the above expressions (6) and (8). And the distance dy in the Y direction is obtained, and the position of the center of gravity 31 is estimated (step S12). Next, in the motion state detection means specifying procedure, a plurality of motion state detection means provided as described above, that is, of the lateral G sensor 40 and the yaw rate sensor 41, are closest to the position of the center of gravity 31 estimated in step S12. The lateral G sensor 40 and the yaw rate sensor 41 located at the position are specified (step S13). The specified lateral G sensor 40 and yaw rate sensor 41 are located at the position where the lateral G sensor 40 and yaw rate sensor 41 are provided by the center of gravity position motion state detection procedure, that is, the lateral G or yaw in the vicinity of the center of gravity 31 position. An angular velocity is detected (step S14).

  Next, in the motion characteristic estimation procedure, from the lateral G detected by the lateral G sensor 40 and the yaw angular velocity detected by the yaw rate sensor 41 and the equation (9), the vehicle side slip is determined as the motion characteristic of the traveling vehicle 70. The angle is estimated (step S15). Furthermore, the vehicle side slip angle estimated in this motion characteristic estimation procedure is output to the display monitor 60 provided in the vehicle (step S16), whereby the current traveling state of the vehicle 70 can be grasped. Further, after that, by returning to the traveling state detection procedure (step S11) again, the vehicle side slip angle of the traveling vehicle 70 can be continuously estimated.

  The above-described vehicle motion characteristic estimation device 80 is provided with a plurality of lateral G sensors 40 and yaw rate sensors 41 serving as motion state detection means, and among these lateral G sensors 40 and yaw rate sensors 41, a gravity center position estimation procedure (step S12). The lateral G sensor and the yaw rate sensor located at the position closest to the center of gravity estimated in (1) are specified by the motion state detection means specifying procedure (step S13). Thereby, the specified lateral G sensor 40 and yaw rate sensor 41 are located in the vicinity of the center of gravity 31 position, and the motion state in the vicinity of the center of gravity 31 position can be detected (step S14). As a result, the motion characteristics of the traveling vehicle 70 can be estimated with high accuracy.

  Further, a plurality of lateral G sensors 40 and yaw rate sensors 41 are provided, and the closest one of the positions of the center of gravity 31 is specified, and the result detected by the lateral G sensor 40 and the yaw rate sensor 41 is determined as the lateral G The yaw angular velocity is used. This eliminates the need for means for moving the lateral G sensor 40 or the like to the position of the center of gravity 31, thereby simplifying the structure and suppressing malfunction of the vehicle motion characteristic estimation device 80 due to failure of the means for moving. be able to. As a result, it is possible to estimate the motion characteristics of the traveling vehicle 1 more reliably.

  The vehicle motion characteristic output device included in the vehicle motion characteristic estimation devices 10 and 80 according to the first and second embodiments displays the vehicle side slip angle line 62 corresponding to the vehicle side slip angle on the display monitor 60. Although the motion characteristics of the driving vehicles 1 and 70 are output to the driver, the vehicle motion characteristics output device may output other than the display by the vehicle side slip angle graph 61. For example, the vehicle motion characteristic output device may take any form as long as it can be displayed visually, such as a lamp blinking in accordance with the vehicle side slip angle.

  Further, the vehicle motion characteristic output device may output to the driver not only by visual display by the display monitor 60 or the like but also by sound such as an alarm. For example, an alarm is sounded when the vehicle side slip angle line 62 enters the caution range 64 or the danger range 65 of the vehicle side slip angle graph 61, and the alarm sound is changed between the caution range 64 and the danger range 65. The sound may be output to the driver according to the degree of danger during traveling. In this way, by sounding an alarm together with the display by the display monitor 60, it is possible to recognize the motion characteristics of the vehicles 1 and 70 without visually recognizing the display monitor 60 during vehicle operation. As a result, the safety during driving of the vehicle can be further improved. Further, only the alarm sound may be used without using the display monitor 60. By using only the alarm sound in this way, the manufacturing cost of the vehicle motion characteristic output device can be suppressed.

  Further, the vehicle side slip angle estimated by the vehicle motion characteristic estimation method is not only output to a vehicle motion characteristic output device such as the display monitor 60 but also the vehicle travel for controlling an engine (not shown), a brake (not shown), and the like. A controller (not shown) may be provided and output to the vehicle travel controller. In this way, by outputting the vehicle side slip angle to the vehicle travel control unit that controls the engine or the like, the engine, the brake, or the like is automatically controlled according to the situation of the vehicle side slip angle, and excessive oversteer is performed. It is possible to automatically avoid dangerous situations. As a result, safety during vehicle travel can be further improved.

  In the motion characteristic estimation procedure (steps S5 and S15), the vehicle side slip angle is estimated as the motion characteristic of the traveling vehicles 1 and 70. However, the motion characteristic to be estimated may be other than the vehicle side slip angle. . In the running state detection procedure (steps S1 and S11), the vehicle speed sensor 46 and the load sensor 50 detect the load acting on the vehicle speed and the wheels 20, but the detected running state is the load acting on the vehicle speed and the wheels 20. Other than that. In the center of gravity position motion state detection procedure (steps S4 and S14), the lateral G and yaw angular velocity are detected as the motion state at the center of gravity 31 position. Other than the yaw angular velocity may be used. Other than these, as long as the position of the center of gravity 31 can be estimated from the traveling state of the traveling vehicles 1 and 70 and the motion characteristics of the vehicles 1 and 70 can be estimated from the estimated position of the center of gravity 31, Other estimation methods may be used.

  As described above, the vehicle motion characteristic estimation method according to the present invention is useful for all vehicles, and is particularly suitable for vehicles in which a lateral load is likely to be applied during traveling.

It is the schematic of the vehicle by which Example 1 of the vehicle motion characteristic estimation apparatus to which this invention is applied is mounted. It is an AA arrow line view of FIG. It is a BB arrow line view of FIG. It is CC arrow line view of FIG. It is a front view of the display monitor with which the said vehicle motion characteristic estimation apparatus of FIG. 1 is equipped. It is a flowchart which shows the estimation pattern of the vehicle motion characteristic of the vehicle motion characteristic estimation apparatus of FIG. It is the schematic of the vehicle by which Example 2 of the vehicle motion characteristic estimation apparatus to which this invention is applied is mounted. It is a flowchart which shows the estimation pattern of the vehicle motion characteristic of the vehicle motion characteristic estimation apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 10 Vehicle motion characteristic estimation apparatus 20 Wheel 21 Left front wheel 22 Right front wheel 23 Left rear wheel 24 Right rear wheel 30 Static gravity center 31 Center of gravity 40 Lateral G sensor 41 Yaw rate sensor 45 Control unit 46 Vehicle speed sensor 50 Load sensor 51 Left front wheel load Sensor 52 Right front wheel load sensor 53 Left rear wheel load sensor 54 Right rear wheel load sensor 60 Display monitor 61 Vehicle side slip angle graph 62 Vehicle side slip angle line 63 Safety range 64 Caution range 65 Danger range 70 Vehicle 80 Vehicle motion characteristic estimation device

Claims (7)

A driving state detection procedure for detecting the driving state of the vehicle;
A center-of-gravity position estimation procedure for estimating a center-of-gravity position during travel of the vehicle from the travel state detected by the travel state detection procedure;
A movement state detection means moving procedure for moving a movement state detection means for detecting a movement state of the vehicle to the gravity center position estimated in the gravity center position estimation procedure;
A center of gravity position motion state detection procedure for detecting the motion state of the vehicle at the center of gravity position estimated by the center of gravity position estimation procedure by the motion state detection means;
A motion characteristic estimation procedure for estimating a motion characteristic of the vehicle from the motion state at the center of gravity position detected by the gravity center position motion state detection procedure;
A vehicle motion characteristic estimation method comprising: A driving state detection procedure for detecting the driving state of the vehicle;
A center-of-gravity position estimation procedure for estimating a center-of-gravity position during travel of the vehicle from the travel state detected by the travel state detection procedure;
Among the plurality of movement state detection means for detecting the movement state of the vehicle, the movement state detection means specifying procedure for specifying the movement state detection means located at the position closest to the gravity center position estimated by the gravity center position estimation procedure; ,
A center of gravity position motion state detection procedure for detecting the motion state of the vehicle at the center of gravity position estimated by the center of gravity position estimation procedure by the motion state detection means identified by the motion state detection means identification procedure;
A motion characteristic estimation procedure for estimating a motion characteristic of the vehicle from the motion state at the center of gravity position detected by the gravity center position motion state detection procedure;
A vehicle motion characteristic estimation method comprising: A lateral G sensor and a yaw rate sensor are used as the motion state detection means,
2. The vehicle side slip angle obtained based on a lateral G detected by the lateral G sensor and a yaw angular velocity detected by the yaw rate sensor is determined by the motion characteristic estimation procedure. Or the vehicle motion characteristic estimation method according to 2; The center-of-gravity position estimation procedure is expressed by the following formula (1) when the distance in the X direction from the static center of gravity position of the vehicle is dx and the distance in the Y direction from the static center of gravity position of the vehicle is dy. 4. The vehicle motion characteristic estimation method according to claim 1, wherein the center-of-gravity position is estimated from dx and dy obtained by (2).
dx = ((Wf1-Wf2) df + (Wr1-Wr2) dr) / 2W (1)
dy = ((Wr1 ′ + Wr2 ′) / W ′ − (Wr1 + Wr2) / W) × L (2)
In the above equations (1) and (2), the dynamic load of the left front wheel is Wf1, the dynamic load of the right front wheel is Wf2, the distance between the front wheel axles is df, and the dynamic load of the left rear wheel is Wr1, The dynamic load of the right rear wheel is Wr2, the distance between the rear wheel axles is dr, the total dynamic load of the vehicle is W, the static load of the left rear wheel is Wr1 ′, and the static load of the right rear wheel is Wr2 ′. The total static load of the vehicle is W ′ and the wheelbase is L.   A computer program for estimating vehicle motion characteristics, which causes a computer to execute the vehicle motion characteristics estimation method according to any one of claims 1 to 4.   A vehicle motion characteristic estimation device comprising a control device that executes the computer program for vehicle motion characteristic estimation according to claim 5.   5. A vehicle motion characteristic output device that outputs to the driver of the vehicle the motion characteristic estimated by the motion characteristic estimation procedure of the vehicle motion characteristic estimation method according to claim 1. The vehicle motion characteristic estimation device according to claim 6.

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