Vehicle control device and traveling state determination method

Abstract

To improve the performance of posture control of a vehicle using jump determination.SOLUTION: When vertical acceleration Az of a vehicle satisfies a first condition (Az≤Th1 or Az≥Th2), the vehicle is determined to be in a special traveling state where it is traveling with at least one wheel floating. When the vertical acceleration Az continuously satisfies a second condition (Th3≤Az≤Th4) for a fixed period while the special traveling state is determined, the vehicle is determined to be in a steady traveling state where it is traveling with all wheels grounded. In particular, preferably the special traveling state is determined during direct-advance traveling.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a vehicle control device and a driving condition determination method. [Background technology]

[0002] In recent years, technological developments related to attitude control of vehicles such as motorcycles have been progressing, and related inventions have been made public. For example, Patent Document 1 discloses a suspension system that judges whether or not a jump is occurring based on vertical acceleration, and increases the damping force of a damping device if a jump is occurring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6444472 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventionally, with regard to vehicle attitude control, there is still room for improvement when jump judgment is performed. In view of the above circumstances, an object of the present invention is to improve the performance of vehicle attitude control that utilizes jump judgment. [Means for solving the problem]

[0005] The present invention, which solves the above problem, is a vehicle control device having a driving judgment unit that judges the driving state of the vehicle, wherein the driving judgment unit judges that the vehicle is in a special driving state in which at least one wheel is off the ground when the vertical acceleration of the vehicle satisfies a first condition, and judges that the vehicle is in a steady driving state in which all wheels are on the ground when the vertical acceleration continues to satisfy a second condition for a certain period of time while determining that the vehicle is in the special driving state. Effect of the Invention

[0006] According to the present invention, it is possible to improve the performance of vehicle attitude control using jump judgment. [Brief description of the drawings]

[0007] [Figure 1] 2 is a functional configuration diagram of a vehicle control device according to the present embodiment. FIG. [Diagram 2] FIG. 13 is an explanatory diagram regarding calculation of a static roll angle. [Diagram 3] FIG. 4 is an explanatory diagram regarding a change in static roll angle depending on a riding posture. [Figure 4] FIG. 13 is an explanatory diagram regarding calculation of a dynamic roll angle. [Diagram 5] 1 is a graph showing a change in vertical acceleration when performing a wheelie. [Figure 6] FIG. 4 is an explanatory diagram of a riding posture map. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. Each drawing is merely a schematic illustration to allow a sufficient understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. In each drawing, common or similar components are denoted by the same reference numerals, and duplicated explanations thereof will be omitted. In this embodiment, a motorcycle will be described as an example of a vehicle. For ease of explanation, the traveling direction of the two-wheeled vehicle is defined as "forward", and the directions of "rearward", "left and right" (lateral), "upward" and "downward" (direction of gravity) are defined.

[0009] [composition] FIG. 1 is a functional configuration diagram of a vehicle control device in this embodiment. The vehicle control device 100 is mounted on a two-wheeled vehicle (a bar-handle vehicle). The vehicle control device 100 is a computer that performs calculations related to the attitude control of the two-wheeled vehicle. In particular, the vehicle control device 100 functions as a roll angle calculation device that calculates the roll angle of a two-wheeled vehicle that is turning. The vehicle control device 100 includes hardware such as an input unit, an output unit, a control unit, and a storage unit. For example, when the control unit is configured with a CPU (Central Processing Unit), information processing by a computer including the control unit is realized by program execution processing by the CPU. In addition, the storage unit included in the computer stores various programs for realizing the functions of the computer according to commands from the CPU. This realizes cooperation between software and hardware.

[0010] The vehicle control device 100 is communicatively connected to a vehicle speed sensor 200 and an IMU 300 (Inertial Measurement Unit). The vehicle speed sensor 200 detects the vehicle speed V of the two-wheeled vehicle. For example, the vehicle speed sensor 200 is attached to a wheel of the two-wheeled vehicle, and can detect the vehicle speed V based on the wheel speed obtained by counting the number of rotations of the wheel per unit time. The vehicle speed sensor is generally provided on either the front and rear wheels, or the front or rear wheels, but in this embodiment, the vehicle speed sensor is described as being provided on at least one wheel. The vehicle speed V is input to the vehicle control device 100 from the vehicle speed sensor 200. The IMU 300 is, for example, a six-axis IMU, and detects the longitudinal acceleration A of the two-wheeled vehicle. x , lateral acceleration A y , vertical acceleration A z , roll angular velocity ω r , pitch angular velocity ω p , and yaw angular velocity ω y The vehicle control device 100 detects (measures) the longitudinal acceleration A x , lateral acceleration A y , vertical acceleration A z , roll angular velocity ω r , pitch angular velocity ω p , and yaw angular velocity ω yThe longitudinal acceleration A x , lateral acceleration A y , vertical acceleration A z , roll angular velocity ω r , pitch angular velocity ω p , and yaw angular velocity ω y is a value obtained by converting the output of the sensor axis output from the IMU 300 into the vehicle axis. For example, when the vehicle is tilted, the vertical acceleration A z The direction of is not the direction of gravity but is inclined with respect to the direction of gravity.

[0011] The vehicle control device 100 includes a geometric calculation unit 1, a static roll angle calculation unit 2 (first roll angle calculation unit), a dynamic roll angle calculation unit 3 (second roll angle calculation unit), a riding posture correction value calculation unit 4 (posture angle calculation unit), an error estimation unit 5 (roll angle error estimation unit), and an output processing unit 6. The geometric calculation unit 1 outputs values ​​used in calculations for vehicle control based on geometric information that represents the shape and attitude of the two-wheeled vehicle. The static roll angle calculation unit 2 calculates the static roll angle φ s Calculate the static roll angle φ s is the time-independent roll angle. The dynamic roll angle calculation unit 3 calculates the dynamic roll angle φ d Calculate the dynamic roll angle φ d is the time-dependent roll angle. d is the roll angular velocity ω r On the other hand, the static roll angle φ s is the roll angular velocity ω r can be calculated without integrating with respect to time. The riding posture correction value calculation unit 4 calculates a correction value caused by the riding posture of the motorcycle as a riding posture correction value. The riding posture correction value is calculated based on the static roll angle φ s The riding posture correction value calculation unit 4 can also calculate the riding posture of the two-wheeled vehicle. The error estimation unit 5 estimates the dynamic roll angle φ dThe error contained in is estimated as the dynamic roll angle error. The output processing unit 6 outputs the dynamic roll angle φ d is output as the roll angle φ of the motorcycle.

[0012] [Estimation of dynamic roll angle error] As shown in Fig. 1, the error estimation unit 5 includes a filter reset determination unit 51 (special driving determination unit, driving determination unit) and a complementary filter calculation unit 52 (roll angle error estimation unit). The filter reset determination unit 51 determines whether or not to perform calculations by the complementary filter calculation unit 52 depending on the driving state of the two-wheeled vehicle. The complementary filter calculation unit 52 calculates the static roll angle φ s and dynamic roll angle φ d The calculation error included in is estimated by a Kalman filter. The Kalman filter is a calculation method for estimating an internal state from observed values ​​(including errors and noise) acquired by sensors (in this embodiment, the vehicle speed sensor 200 and the IMU 300). For example, the filter reset determination unit 51 can function as a calculation unit that calculates values ​​to be input to the complementary filter calculation unit 52, but is not limited to this. In this embodiment, the description will continue assuming that the filter reset determination unit 51 is such a calculation unit.

[0013] The static roll angle φ calculated by the static roll angle calculation unit 2 s and the dynamic roll angle φ calculated by the dynamic roll angle calculation unit 3 d is input to the filter reset decision unit 51. The filter reset decision unit 51 determines whether the static roll angle φ s and dynamic roll angle φ d The difference between the static roll angle φ and the static roll angle φ is calculated and output as a roll angle difference. The roll angle difference is input to a complementary filter calculation unit 52. The complementary filter calculation unit 52 can estimate the calculation error included in the roll angle difference by a Kalman filter. The calculation error included in the roll angle difference is calculated by subtracting the static roll angle φ from the static roll angle φ. s Calculation error and dynamic roll angle φ d The complementary filter calculation unit 52 calculates the static roll angle φ from the calculation errors included in the roll angle difference. sCalculation error and dynamic roll angle φ d In this embodiment, the complementary filter calculation unit 52 estimates the calculation error included in the static roll angle φ s and dynamic roll angle φ d Based on the roll angle difference, the dynamic roll angle φ d and outputs the calculated error to the dynamic roll angle calculation unit 3 as the dynamic roll angle error.

[0014] The dynamic roll angle calculation unit 3 calculates the dynamic roll angle φ using the dynamic roll angle error output from the complementary filter calculation unit 52 of the error estimation unit 5. d The dynamic roll angle φ with the dynamic roll angle error removed can be calculated. d The obtained dynamic roll angle φ d is input to the output processing unit 6. The output processing unit 6 outputs the dynamic roll angle φ d The resultant dynamic roll angle φ can be output as the roll angle φ of the motorcycle. d is input to the error estimator 5 and can be used for estimation by the complementary filter calculator 52. As a result, the dynamic roll angle φ d For example, the complementary filter calculation unit 52 can output to the dynamic roll angle calculation unit 3 a dynamic roll angle error whose estimation accuracy has been improved to a certain level or higher.

[0015] When estimating the sensor error of the IMU by a Kalman filter to calculate the roll angle of a motorcycle, conventionally, it was necessary to perform arithmetic operations using a 5×5 matrix with five types of observation values ​​(roll acceleration, roll angular velocity, yaw acceleration, yaw angular velocity, and longitudinal acceleration) output by the IMU as input, which posed a problem of a very large calculation load. According to this embodiment, the input value used for estimation by the Kalman filter is the static roll angle φ s and dynamic roll angle φ d Therefore, the calculations performed in the sensor error estimation of the IMU 300 are arithmetic operations using a 2 × 2 matrix, and the calculation load due to matrix calculations can be minimized. As a result, the calculation load for calculating the roll angle of the motorcycle can be reduced.

[0016] In order to reduce the amount of calculations involved in error estimation by the Kalman filter while maintaining the accuracy of the finally calculated roll angle φ of the two-wheeled vehicle at a certain level or higher, it is preferable to appropriately adjust the calculations and controls performed by the vehicle control device 100. The following describes a method of such adjustment.

[0017] [Static roll angle φ s Calculation details] Static roll angle φ s can be calculated using the following formula (1).

[0018]

number

[0019] Here, R is the turning radius of the motorcycle during a turn. g is the gravitational acceleration. m φ is a geometric bank angle conversion coefficient, which is a constant that can be uniquely determined from the shape and posture of the motorcycle. 2 / R) is the centripetal acceleration, pointing towards the turning center. g is the direction of gravity. That is, according to equation (1), the static roll angle φ s is the direction of the turning center (V 2 / R) and the arctangent of the gravitational force g. The vehicle speed V can be obtained, and is expressed as g, m φ Since is known, the static roll angle φ s In order to calculate the turning radius R, it is necessary to calculate the static roll angle. FIG. 2 is an explanatory diagram regarding the calculation of the static roll angle. In order to calculate the turning radius R (radius of a virtual stationary circle), the yaw angular velocity ω y Instead of using the yaw angular velocity of the gravity axis, it is necessary to use the yaw angular velocity of the gravity axis (the yaw angular velocity of the horizontal axis does not contribute to turning). yThe yaw angular velocity of the gravity direction axis can be calculated by performing coordinate transformation so that the bank angle of the two-wheeled vehicle M is rotated by the bank angle of the two-wheeled vehicle M. The bank angle is the roll angle φ, or more accurately, the previous value of the static roll angle. The calculated yaw angular velocity of the gravity direction axis is input to the static roll angle calculation unit 2. Note that the previous value of the roll angle φ (the roll angle φ last output by the output processing unit 6) can also be used.

[0020] The static roll angle calculation unit 2 calculates the static roll angle φ using the formula (1). s (provisional first roll angle) can be calculated. At this time, the pitch angular velocity ω p It is advisable to use the yaw angular velocity of the gravity direction axis calculated using

[0021] Also, the yaw angular velocity ω y changes depending on the riding posture. The riding posture is, for example, lean-in or lean-out of the rider. The riding posture includes the posture of the moving vehicle taking into account not only the rider riding on the motorcycle, but also the load including the baggage loaded on the motorcycle. FIG. 3 is an explanatory diagram regarding the change in the static roll angle depending on the riding posture. If the motorcycle is lean-with, the static roll angle of the motorcycle M indicates the true roll angle φ2 calculated based on the center of gravity of the vehicle. If the motorcycle is lean-in as shown in FIG. 3, the static roll angle of the motorcycle M increases and indicates the static roll angle φ1 calculated based on the center of gravity generated by the riding posture. In other words, even if the inclination (bank angle) of the motorcycle M is the same, the turning radius when leaning in is smaller than the turning radius when leaning with. Therefore, when the motorcycle is leaning in, the yaw angular velocity ω y As a result, the static roll angle increases when the vehicle leans in.

[0022] In view of the above, if the influence of riding posture can be estimated, the yaw angular velocity ω y Since the change in the static roll angle φ s The effect of riding posture is corrected by the lateral acceleration A measured by the IMU300. y Change in and vertical acceleration A zAs shown in Fig. 1, the riding posture correction value calculation unit 4 includes a first posture angle estimation unit 41, a second posture angle acquisition unit 42, a posture angle difference calculation unit 43, and a riding posture map 44.

[0023] The first posture angle estimator 41 estimates a first posture angle φ1 that is determined based on the center of gravity generated by the riding posture. The first posture angle φ1 is calculated based on the lateral acceleration A y , and the vertical acceleration A acting in the direction of gravity of the motorcycle. z This is the angle calculated from The second attitude angle acquisition unit 42 acquires the second attitude angle φ2 that is determined based on the vehicle center of gravity. The attitude angle difference calculation unit 43 calculates the difference α (see FIG. 3) between the first attitude angle φ1 and the second attitude angle φ2. The riding posture map 44 is a map used to acquire the second posture angle φ2. The riding posture map 44 is a map used to acquire the second posture angle φ2. y , and the vertical acceleration A acting in the direction of gravity on the motorcycle M z This map was created based on (details below).

[0024] The riding posture correction value calculation unit 4 outputs the difference α as a riding posture correction value to the static roll angle calculation unit 2. The static roll angle calculation unit 2 uses the riding posture correction value to calculate the static roll angle φ s (Provisional first roll angle) can be corrected. Static roll angle φ corrected with riding posture correction value s (Determined first roll angle) is output to the error estimation unit 5. Note that the riding posture correction value (difference α) is a value that indicates the influence of the riding posture itself, and the yaw angular velocity ω y The static roll angle calculation unit 2 can correct the yaw angular velocity of the gravity direction axis (see FIG. 2) input from the geometric calculation unit 1 with the riding attitude correction value. As a result, the static roll angle calculation unit 2 calculates the static roll angle φ s (Determined first roll angle) can be calculated. Note that a functional unit combining the static roll angle calculation unit 2 and the riding posture correction value calculation unit 4 may be referred to as the static roll angle calculation unit 2 (first roll angle calculation unit).

[0025] [Dynamic roll angle φ d Calculation details] <Advance direction correction> Dynamic roll angle φ d is the roll angular velocity ω detected by the IMU300. r The integral interval is, for example, the period from the time when the previous value of the roll angle φ is output to the time when the current value of the roll angle φ is output. When a motorcycle turns, the banking direction changes. That is, the roll angular velocity ω r The axis of the dynamic roll angle φ d The roll angular velocity ω integrated in the calculation of r is the roll angular velocity of the traveling direction axis. Therefore, by calculating the roll angular velocity of the traveling direction axis, the dynamic roll angle φ d The calculation accuracy can be improved.

[0026] FIG. 4 is an explanatory diagram relating to the calculation of a dynamic roll angle. FIG. 4 is a plan view showing geometric information relating to a two-wheeled vehicle (only the front wheel Tf and the rear wheel Tr are shown) that has been steered without banking. As shown in FIG. 4, a traveling direction angle D occurs to the two-wheeled vehicle when turning. The traveling direction angle D is the angle between the traveling direction axis of the two-wheeled vehicle M when turning, and a straight line that has the position of the IMU 300 (not shown in FIG. 4) as the rotation center and passes through the center of the front wheel Tf and the center of the rear wheel Tr. In FIG. 4, R is the turning radius, C is the distance between the position of the IMU 300 (not shown in FIG. 4) and the center of the rear wheel Tr, WB is the distance between the center of the front wheel Tf and the center of the rear wheel Tr, and δ is the turning radius. w is the steering angle.

[0027] According to the geometric information shown in FIG. 4, the travel direction angle D is D=sin -1 (C / R). In other words, the heading angle D can be calculated from the turning radius R. Note that R=V / ω y ω yis the yaw angular velocity of the vehicle axis, but it is preferable to use the yaw angular velocity of the gravity axis (see FIG. 2). The roll angular velocity of the travel direction axis is the roll angular velocity ω r This calculation is performed by the geometry calculation unit 1. The geometry calculation unit 1 outputs the calculated roll angular velocity of the traveling direction axis to the dynamic roll angle calculation unit 3. The dynamic roll angle calculation unit 3 integrates the roll angular velocity of the traveling direction axis with respect to time to obtain the dynamic roll angle φ d The dynamic roll angle calculation unit 3 calculates the dynamic roll angle φ using the roll angular velocity of the traveling direction axis and the dynamic roll angle error output by the error estimation unit 5. d can be calculated (calculated with feedback).

[0028] At this time, the dynamic roll angle calculation unit 3 calculates the pitch angular velocity ω p Further, the dynamic roll angle φ d It is preferable to calculate the pitch angular velocity ω p This is because the horizontal component of the rotation axis (extending diagonally upward or downward) of the roll angular velocity of the traveling direction axis can be obtained by using the dynamic roll angle φ d Since it does not contribute to the pitch angular velocity ω p By using the dynamic roll angle φ d The calculation accuracy can be further improved.

[0029] <Steering correction for estimation errors using Kalman filter> When turning (when the steering is turned), that is, when a steering angle is generated, the static roll angle φ s, the calculation accuracy of the error estimation by the Kalman filter in the complementary filter calculation unit 52 decreases. Therefore, in order to maintain the error estimation accuracy at a certain level or higher while suppressing the calculation load, it is preferable to adjust the error when a steering angle is generated. Specifically, it is preferable for the complementary filter calculation unit 52 to adjust the term relating to the error estimated by the Kalman filter with the steering angle. By such an adjustment, the error estimation unit 5 can correct the dynamic roll angle error by using the steering angle of the two-wheeled vehicle. In addition, the dynamic roll angle calculation unit 3 uses the corrected dynamic roll angle error to calculate the dynamic roll angle φ d can be calculated.

[0030] <Disabling the Kalman filter during special driving> Static roll angle φ s The formula (1) used to calculate is not designed for special driving such as jumping or doing a wheelie. Therefore, the accuracy of error estimation by the Kalman filter is poor during special driving. Also, it is better not to activate controls such as ABS (Antilock Braking System) during jumping. In view of this, it is better to disable the Kalman filter during special driving rather than improving the accuracy of error estimation during special driving. Disabling the Kalman filter in this way makes it possible to achieve both the calculation accuracy and calculation load required for cornering ABS control.

[0031] Specifically, first, the filter reset determination unit 51 shown in FIG. 1 determines whether the motorcycle is in special driving mode. The determination of whether the motorcycle is in special driving mode will be described later. If the filter reset determination unit 51 determines that the motorcycle is not in special driving mode, the filter reset determination unit 51 outputs a reset determination result indicating that to the complementary filter calculation unit 52. The complementary filter calculation unit 52 enables the Kalman filter in accordance with the reset determination result and performs error estimation. On the other hand, if the filter reset determination unit 51 determines that the motorcycle is in special driving mode, the filter reset determination unit 51 outputs a reset determination result indicating that to the complementary filter calculation unit 52. The complementary filter calculation unit 52 disables the Kalman filter in accordance with the reset determination result and does not perform error estimation. In this case, the dynamic roll angle error is not output to the dynamic roll angle calculation unit 3.

[0032] [Determining whether or not special driving is in progress] The determination of whether or not the vehicle is in special driving is based on the vertical acceleration A z This can be achieved by tracking the change in vertical acceleration (A). Figure 5 is a graph showing the change in vertical acceleration when performing a wheelie. The horizontal axis of the graph in Figure 5 is time, and the vertical axis is vertical acceleration (A z ) The vertical axis of the graph is positive (+) downward and negative (-) upward. As shown in the graph in Figure 5, when a wheelie is performed, the vertical acceleration A z shows a large amplitude. Therefore, the filter reset determination unit 51 z Four thresholds Th1 to Th4 are prepared for the threshold value Th1 to Th4, which satisfy the relation Th1>Th4>0>Th3>Th2.

[0033] Vertical acceleration A measured by IMU300 z is input to the filter reset determination unit 51. z ≦Th1 or A z If the condition Th2 (first condition) is satisfied, the filter reset determination unit 51 determines that the motorcycle is performing a wheelie. At this time, it is not necessary to perform the calculation of error estimation using the Kalman filter (no calculation is performed in this embodiment). z≧Th2 indicates when the wheel is lifted off the ground. z The time Th1 indicates when the lifted wheel lands. Also, while the filter reset determination unit 51 determines that the vehicle is performing a wheelie, the vertical acceleration A z Th4 ≧ A z If the condition Th3 (second condition) is satisfied for a certain period of time, the filter reset determination unit 51 determines that the motorcycle has returned to a steady running state from a wheelie. At this time, the error estimation calculation should be performed using the Kalman filter (this is performed in this embodiment).

[0034] More generally, the above judgment can be applied to special driving conditions other than wheelie driving (e.g. jumps, rear lifts). z If the first condition is satisfied within a predetermined period, the filter reset determination unit 51 determines that the vehicle is in a special driving state in which at least one wheel is lifted off the ground. Also, while the filter reset determination unit 51 determines that the vehicle is in a special driving state, z If the second condition is continuously satisfied for a certain period of time, the filter reset determination unit 51 determines that the vehicle is in a steady running state in which all wheels are in contact with the ground. Note that the threshold values ​​Th1 to Th4 can be appropriately changed depending on the type of special running state.

[0035] Th3 and Th4 function as branching points between a normal driving state and an abnormal driving state, and can be the normal determination thresholds shown in Fig. 5. Th1 and Th2 function as branching points between an abnormal driving state and an abnormal state (a state deviating from the abnormal driving state), and can be the abnormal determination thresholds shown in Fig. 5. The special driving judgment section shown in Fig. 5 is the period from the time when the first condition is satisfied for the first time to the end of the certain period during which the second condition is continuously satisfied. The normal driving judgment section shown in Fig. 5 is the period other than the special driving judgment section.

[0036] It is preferable that the filter reset determination unit 51 determines that the vehicle is in the special driving state when the vehicle is traveling straight ahead. When turning, the accuracy of the determination as to whether or not the vehicle is in the special driving state decreases, and if it is determined that the vehicle is not in the special driving state, this may lead to a decrease in the accuracy of the error estimation by the Kalman filter. By limiting the determination as to whether or not the vehicle is in the special driving state to when the vehicle is traveling straight ahead, the determination accuracy can be maintained at a certain level or higher, and the accuracy of the error estimation by the Kalman filter can be maintained at a certain level or higher.

[0037] [Steering angle calculation] The vehicle control device 100 can calculate the steering angle, which affects the accuracy of error estimation by the Kalman filter in the complementary filter calculation unit 52, using only the vehicle speed sensor 200 and the IMU 300. In other words, the vehicle control device 100 can calculate the steering angle without using a steering angle sensor. By configuring a system in which a steering angle sensor is not mounted on the two-wheeled vehicle, it is possible to reduce the calculation load caused by weight changes accompanying mounting of a sensor, and to facilitate implementation of the vehicle control device 100 with the number of types of sensors used minimized. Note that the present invention does not exclude the use of a steering angle sensor or mounting it on the two-wheeled vehicle. According to the Automotive Technology Handbook, steering angle δ H can be calculated using the following formula (2).

[0038]

number

[0039] Here, δ w is the steering angle (see Fig. 4). φ is the roll angle. ε is the caster angle on the front wheel side. "atan" is "arctan" or "tan -1 " means. The previous value of the static roll angle can be used as the roll angle φ. Also, a roll angle sensor may be provided on the two-wheeled vehicle, and the roll angle φ may be acquired from the roll angle sensor and used. The roll angle sensor may be, for example, a 9-axis IMU, but is not limited to this.

[0040] According to FIG. 4, the steering angle δ w can be calculated using the following formula (3).

[0041]

number

[0042] According to the formula (2) and the formula (3), the steering angle δ H can be expressed by geometric information of the shape and posture of the motorcycle. The geometric calculation unit 1 calculates the steering angle δ by using the formulas (2) and (3). H In other words, the geometric calculation unit 1 calculates the traveling direction angle D of the two-wheeled vehicle from the yaw angular velocity of the gravity direction axis and the wheel speed (vehicle speed V), and calculates the steering angle δ using the traveling direction angle D and the roll angle φ. H The calculated steering angle δ H is input to a complementary filter calculation unit 52, and a term related to the error estimated by the Kalman filter is calculated based on the steering angle δ H By such adjustment, the error estimator 5 can estimate the steering angle δ of the motorcycle. H The dynamic roll angle calculation unit 3 can correct the dynamic roll angle error by using the corrected dynamic roll angle error. d can be calculated.

[0043] Here, since the geometric calculation unit 1 calculates the traveling direction angle using the yaw angular velocity measured by the IMU 300, it is preferable to calculate the traveling direction angle based on the height of the IMU 300 from the road surface. In other words, when the height of the IMU 300 from the road surface is h, the traveling direction angle D=sin -1 The turning radius R used in the calculation of (C / R) is replaced with R - h·sinφ to calculate the heading angle D, and the steering angle δ H This eliminates the turning radius error in the height direction before calculating the heading angle D, so the steering angle δ H The calculation accuracy can be improved.

[0044] [Estimation of riding posture] The vehicle control device 100 determines the static roll angle φs The riding posture that affects the lean-with can be estimated using only the IMU 300. FIG. 6 is an explanatory diagram of a riding posture map. As shown in a riding posture map 44 in FIG. 6, for five types of riding postures, namely lean-with, shallow lean-in riding posture A, deep lean-in riding posture B, shallow lean-out riding posture C, and deep lean-out riding posture D, the horizontal axis is the bank angle (same as the roll angle φ) and the vertical axis is atan(A y / A z ) the following features 1 and 2 can be seen.

[0045] Feature 1: Even with the same roll angle φ, atan(A y / A z ) values ​​are different. Feature 2: If the riding posture is constant, atan(A y / A z ) is constant. In other words, for any roll angle φ, the change in the roll angle and atan(A y / A z ) (the slope of the linear line when the plots for each riding position are fitted with a linear line) will be roughly the same value as long as the same riding position is maintained.

[0046] Based on Features 1 and 2, atan(A y / A z ) and atan(A y / A z ) is calculated in advance and recorded in the riding posture map 44. The riding posture correction value calculation unit 4 also refers to the riding posture map 44 and calculates atan(A y / A z Furthermore, the riding posture correction value calculation unit 4 calculates the current lateral acceleration A y and vertical acceleration A z is obtained from IMU300, and the current atan(A y / A z ) value. This calculates the current atan(Ay / A z ) is the value of atan(A y / A z ) (degree of deviation), the riding posture correction value calculation unit 4 can specify the riding posture.

[0047] More specifically, atan(A y / A z The value of atan(A ) corresponds to the second attitude angle φ2 estimated by the second attitude angle acquisition unit 42 (see FIG. 3). y / A z The value of atan(A) corresponds to the first attitude angle φ1 estimated by the first attitude angle estimator 41 (see FIG. 3). y / A z ) and the current calculated atan(A y / A z ) corresponds to the difference α calculated by the attitude angle difference calculation unit 43 (see FIG. 3).

[0048] In the case where a two-wheeled vehicle is a moving vehicle including a vehicle body and a load (including a passenger and baggage), the first attitude angle estimation unit 41 estimates a lateral acceleration A acting in the lateral direction of the moving vehicle. y , and the vertical acceleration A acting in the direction of gravity of the moving vehicle z Based on this, a first attitude angle φ1 with respect to the vertical direction of the center of gravity of the moving vehicle can be estimated. Furthermore, a second attitude angle acquisition unit 42 acquires a second attitude angle φ2 with respect to the vertical direction of the center of gravity of the vehicle (two-wheeled vehicle). An attitude angle difference calculation unit 43 obtains a difference α between the first attitude angle φ1 and the second attitude angle φ2. A riding attitude correction value calculation unit 4 outputs the difference α to the static roll angle calculation unit 2 as a riding attitude correction value. Therefore, the lateral acceleration A y and vertical acceleration A z Based on the static roll angle φ s The difference α, which is the riding posture correction value for correcting the static roll angle φ s can be easily corrected.

[0049] Here, the vertical acceleration A z When becomes extremely small, atan(A y / A z In order to avoid such a situation, the first attitude angle estimator 41 estimates the vertical acceleration A z When the vertical acceleration A becomes equal to or smaller than the first predetermined value, it is preferable to estimate the first posture angle φ1 using the value of the first predetermined value. z By setting the lower limit value of φ1, the first posture angle φ1 can be reliably output without being affected when the motorcycle jumps.

[0050] In addition, the vertical acceleration A z When becomes extremely large, atan(A y / A z ) becomes extremely small, and there is a risk that a difference α that does not match the current riding posture will be output. In order to avoid such a situation, it is preferable that the posture angle difference calculation unit 43 sets the difference α to the second predetermined value when the difference α between the first posture angle φ1 and the second posture angle φ2 becomes equal to or greater than the second predetermined value. By setting an upper limit value for the difference α in this manner, it is possible to reliably output the first posture angle φ1 without being affected when the motorcycle jumps.

[0051] In addition, the second attitude angle acquisition unit 42 acquires a roll angle φ acting on the center of gravity of the vehicle (two-wheeled vehicle), a lateral acceleration A acting in the lateral direction of the vehicle, y , and the vertical acceleration A acting on the vehicle in the direction of gravity z It is preferable to obtain the second posture angle φ2 from the riding posture map 44 created based on the above. By mapping the second posture angle φ2 in this manner, the difference α can be obtained efficiently.

[0052] [summary] According to this embodiment, the static roll angle φ s and the dynamic roll angle φ d After calculating the static roll angle φ, the dynamic roll angle error is estimated, thereby reducing the calculation load for calculating the roll angle φ.s Therefore, the accuracy of the calculation of the roll angle φ can be improved. In addition, the dynamic roll angle φ is calculated by calculating the roll angular velocity of the travel direction axis. d can be corrected in the direction of travel, so the dynamic roll angle φ d The calculation accuracy can be improved. In addition, the steering angle δ of the vehicle H By correcting the dynamic roll angle error using d The calculation accuracy can be improved. In addition, if it is determined that the vehicle is not traveling in a special mode, the dynamic roll angle φ d If the vehicle is judged to be in a special driving state, the dynamic roll angle φ d Since no error estimation is performed, the impact of special driving conditions can be reduced.

[0053] According to this embodiment, the vertical acceleration A z Since the special driving state and the normal driving state can be determined based on the sensor value of IMU300 alone, a simple configuration can be realized to determine the special driving state and the normal driving state. In addition, by determining whether the vehicle is in a special driving state when the vehicle is driving straight ahead, the accuracy of the determination can be improved. In addition, by setting multiple types of threshold values ​​to determine whether a special driving state and a steady driving state are performed, it is possible to improve the accuracy of determining whether a special driving state has started, and it is also possible to improve the accuracy of determining whether a special driving state has ended.

[0054] According to the present embodiment, the steering angle δ is calculated using the travel direction angle D and the roll angle φ. H In order to calculate the steering angle δ without a steering angle sensor, the steering angle δ is calculated using only the sensor value of IMU300. H It is possible to realize control that calculates In addition, since the traveling direction angle D is calculated based on the height of the IMU 300 from the road surface, errors in the turning radius R caused by the height direction can be eliminated, and the calculation accuracy of the traveling direction angle D can be improved.

[0055] According to the present embodiment, the lateral acceleration A yand vertical acceleration A z Based on the static roll angle φ s The difference α, which is the riding posture correction value for correcting the static roll angle φ s can be easily corrected. In addition, the vertical acceleration A z By setting the lower limit value (first predetermined value) of the first posture angle φ1, it is possible to reliably output the first posture angle φ1 without being affected when the two-wheeled vehicle jumps. Moreover, by setting an upper limit value (second predetermined value) of the difference α, the first posture angle φ1 can be reliably output without being affected when the two-wheeled vehicle jumps. Moreover, by mapping the second posture angle φ2, the difference α can be obtained efficiently.

[0056] [Method invention] A first invention of the method is a roll angle calculation method for calculating a roll angle of a vehicle, the roll angle calculation method comprising the steps of: calculating a tentative first roll angle using a yaw angular velocity of a gravity direction axis and a wheel speed calculated from a yaw angular velocity, a pitch angular velocity, and a previous value of a physical quantity related to the roll angle measured by an inertial measurement unit; calculating a riding attitude correction value based on a difference between a first attitude angle calculated based on a center of gravity generated by a riding attitude and a second attitude angle calculated based on a vehicle center of gravity, the first attitude angle being an angle calculated from a lateral acceleration acting in a lateral direction of the vehicle and a vertical acceleration acting in a gravity direction of the vehicle; calculating a finalized first roll angle by correcting the provisional first roll angle with the riding attitude correction value; and estimating a second roll angle error based on a difference between the finalized first roll angle and a second roll angle different from the finalized first roll angle. Further, there is provided a roll angle calculation method according to a first aspect of the present invention, which is characterized in that a traveling direction angle of the vehicle is calculated from a yaw angular velocity of the gravity direction axis and a wheel speed, a roll angular velocity of the traveling direction axis is calculated based on a roll angular velocity measured by an inertial measurement unit and the traveling direction angle, and the second roll angle is calculated using the roll angular velocity of the traveling direction axis and the second roll angle error.

[0057] The second invention of the method is a driving condition determination method for determining the driving condition of a vehicle, which is characterized in that, when the vertical acceleration of the vehicle satisfies a first condition, it is determined that the vehicle is in a special driving condition in which at least one wheel is off the ground, and when the vertical acceleration satisfies a second condition for a certain period of time while it is determined that the vehicle is in the special driving condition, it is determined that the vehicle is in a steady driving condition in which all wheels are on the ground.

[0058] A third invention of the method is a steering angle calculation method, which is characterized by calculating a vehicle's traveling direction angle from the yaw angular velocity of the gravity direction axis and the wheel speed, and calculating the steering angle using the traveling direction angle and roll angle.

[0059] A fourth invention of the method is a method for estimating a riding attitude correction value for a vehicle used in estimating a roll angle of the vehicle, characterized in that a first attitude angle with respect to the vertical direction of the center of gravity of the moving vehicle is estimated based on a lateral acceleration acting in the lateral direction of a moving vehicle including the vehicle and its cargo, and a vertical acceleration acting in the direction of gravity of the moving vehicle, a second attitude angle with respect to the vertical direction of the center of gravity of the vehicle is obtained, a difference between the first attitude angle and the second attitude angle is calculated, and the difference is used as the riding attitude correction value.

[0060] [Variations] (a): In this embodiment, the error estimation unit 5 (complementary filter calculation unit 52) ​​calculates the dynamic roll angle error, and the dynamic roll angle calculation unit 3 calculates the dynamic roll angle φ d However, the error estimation unit 5 (complementary filter calculation unit 52) ​​uses the Kalman filter to correct the static roll angle φ s Since the error of the static roll angle can also be estimated, the static roll angle error is calculated, and the static roll angle calculation unit 2 calculates the static roll angle φ s may be feedback corrected. (b): In this embodiment, the error estimator 5 estimates the steering angle δ H The error estimation by the Kalman filter was adjusted by inputting the above. However, for example, when there is a large steering, that is, when the steering angle δ His equal to or greater than a predetermined value, the accuracy of error estimation by the Kalman filter is expected to decrease significantly, so that error estimation may be controlled not to be performed in the first place. (c): In this embodiment, the filter reset determination unit 51 detects the static roll angle φ s and dynamic roll angle φ d is input, the roll angle difference is calculated, and output to the complementary filter calculation unit 52. However, when the static roll angle φ s and dynamic roll angle φ d may be input, and the complementary filter calculation unit 52 may calculate the roll angle difference and perform error estimation using a Kalman filter. Alternatively, the complementary filter calculation unit 52 may not calculate the roll angle difference, but may use the static roll angle φ s and dynamic roll angle φ d An error estimate may be made for each of

[0061] (d) It is also possible to realize a technology that appropriately combines the various technologies described in this embodiment. (e) The software described in this embodiment can be realized as hardware, and vice versa. (f) In addition, the hardware, software, flow charts, etc. may be modified as appropriate without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0062] 100 Vehicle control device 200 Vehicle speed sensor 300 IMU (Inertial Measurement Unit) 1 Geometric calculation section 2. Static roll angle calculation unit (first roll angle calculation unit) 3 Dynamic roll angle calculation unit (second roll angle calculation unit) 4. Riding posture correction value calculation unit (posture angle calculation unit) 41 First attitude angle estimator 42 Second attitude angle acquisition part 43 Attitude angle difference calculation section 44 Riding posture map 5 Error Estimation Unit (Roll Angle Error Estimation Unit) 51 Filter reset determination unit (special driving determination unit, driving determination unit) 52 Complementary filter calculation unit (roll angle error estimation unit) 6 Output Processing Section

Claims

1. A vehicle control device having a driving determination unit that determines a driving state of a vehicle, The travel determination unit determines that the vehicle is in a special travel state in which at least one wheel is lifted from the ground when the vertical acceleration of the vehicle satisfies a first condition, and A vehicle control device characterized in that, if the vertical acceleration satisfies a second condition for a certain period of time while it is determined that the vehicle is in the special driving state, it is determined that the vehicle is in a steady driving state in which all wheels are on the ground.

2. The vehicle control device according to claim 1, The vehicle control device is characterized in that the driving determination unit determines that the special driving state is occurring when the vehicle is driving straight ahead.

3. The vehicle control device according to claim 1 or 2, the first condition is that the vertical acceleration is equal to or less than a first threshold or equal to or more than a second threshold that is greater than the first threshold, the second condition is that the vertical acceleration is equal to or greater than a third threshold and equal to or less than a fourth threshold that is greater than the third threshold, The vehicle control device according to claim 1, wherein the third threshold value and the fourth threshold value are values ​​between the first threshold value and the second threshold value.

4. A method for determining a vehicle's running state, comprising: When the vertical acceleration of the vehicle satisfies a first condition, it is determined that the vehicle is in a special driving state in which at least one wheel is lifted from the ground, and A driving condition determination method characterized by determining that the vehicle is in a steady driving state in which all wheels are on the ground and driving when the vertical acceleration satisfies a second condition for a certain period of time while it is determined that the vehicle is in the special driving state.

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