WO2022201376A1

WO2022201376A1 - Vehicle attitude angle estimation device and optical axis control device for vehicle lamp

Info

Publication number: WO2022201376A1
Application number: PCT/JP2021/012338
Authority: WO
Inventors: 敏裕和田; 弘毅中本
Original assignee: 三菱電機株式会社
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2022-09-29
Also published as: JP7435900B2; JPWO2022201376A1

Abstract

A vehicle attitude angle estimation device (101) comprises: a static pitch angle estimation unit (205) that estimates a static pitch angle in a vehicle comprising a vehicle body supported from a road surface by a suspension on the basis of acceleration information, altitude information, vehicle speed information, and a constant determined by the suspension; a composite acceleration estimation unit (206) that, from at least the acceleration information and the static pitch angle, estimates an acceleration component parallel to the vehicle advancing direction that is applied to the vehicle body; a pitch angle storage unit (208) that stores the pitch angle of the vehicle body relative to the road surface from a previous calculation cycle; and a pitch angle estimation unit (207) that estimates the pitch angle of the vehicle body relative to the road surface from the acceleration component parallel to the vehicle advancing direction that is applied to the vehicle body, the pitch angle in the previous calculation cycle, and the constant determined by the suspension. This vehicle attitude angle estimation device makes it possible to estimate the attitude angle of a vehicle even when the vehicle is accelerating or decelerating, or undergoing a change in gradient of the road surface.

Description

Vehicle attitude angle estimation device and optical axis control device for vehicle lamp

The present disclosure relates to a device for estimating the attitude angle of a vehicle with respect to the road surface.

Patent Document 1 discloses a method of estimating the pitch angle of a vehicle with respect to the road surface using an acceleration sensor, an altitude sensor, and a vehicle speed sensor. In Patent Document 1, an acceleration sensor is used to detect the absolute pitch angle, which is the pitch angle of the vehicle with respect to the horizontal plane, and the road gradient is calculated based on the amount of change in altitude per unit time measured by the altitude sensor. It is disclosed that a pitch angle to the road surface, which is the pitch angle of the vehicle with respect to the road surface, is calculated from the difference between the obtained road surface gradient and the absolute pitch angle.

JP 2013-112267 A

The pitch angle of the vehicle with respect to the road surface changes depending on the number of passengers and cargo loaded, as well as changes in the slope of the road surface and acceleration/deceleration. If the vehicle is traveling at a constant speed on a road surface with a constant gradient, it is possible to estimate the pitch angle of the vehicle from the horizontal plane by measuring the direction of gravity using an acceleration sensor as described in Patent Document 1. is. Furthermore, by measuring the amount of change in altitude of the vehicle, it is possible to estimate the slope of the road surface on which the vehicle is running from the horizontal plane. It is possible to estimate the pitch angle of the vehicle with respect to

However, when the vehicle is accelerating or decelerating, the measured value of the acceleration sensor is not the direction of gravity, but the combined direction of gravity and vehicle acceleration, so the pitch angle of the vehicle from the horizontal plane cannot be estimated. Furthermore, in a situation where the acceleration of the vehicle is changing, the pitch angular acceleration of the vehicle caused by the change in the acceleration of the vehicle is superimposed on the measurement value of the acceleration sensor. Similarly, in a situation where the gradient of the road surface is changing, the pitch angular acceleration of the vehicle caused by the gradient change of the road surface is superimposed on the measurement value of the acceleration sensor. Therefore, with the method described in Patent Document 1, it is difficult to estimate the pitch angle of the vehicle with respect to the road surface when the vehicle is accelerating or decelerating or when the gradient of the road surface is changing.

On the other hand, for example, in order to achieve optical axis leveling for anti-glare headlamps, it is necessary to adjust the optical axis in response to changes in the pitch angle caused by acceleration and deceleration of the vehicle. For this purpose, it is necessary to estimate the pitch angle of the vehicle with respect to the road surface even during acceleration or deceleration of the vehicle.

A vehicle attitude angle estimation device according to the present disclosure includes:
In a vehicle having a vehicle body supported from the road surface by a suspension, acceleration information obtained from an acceleration sensor provided on the vehicle body, at least altitude information obtained from an altitude sensor, vehicle speed information obtained from a vehicle speed sensor, and the suspension are determined. a static pitch angle estimating unit that estimates a static pitch angle, which is the pitch angle of the vehicle body with respect to the road surface, when the vehicle is not accelerating or decelerating on a flat road surface, based on a constant;
a synthetic acceleration estimator that calculates a component of the acceleration applied to the vehicle body parallel to the traveling direction of the vehicle from the acceleration information obtained from the acceleration sensor and the static pitch angle estimated by the static pitch angle estimator;
a pitch angle storage unit that stores the pitch angle of the vehicle body relative to the road surface in the previous calculation cycle;
It is determined by the component of the acceleration applied to the vehicle body that is estimated by the synthetic acceleration estimator and that is parallel to the traveling direction of the vehicle, the pitch angle of the vehicle body with respect to the road surface in the previous calculation cycle stored in the pitch angle storage unit, and the suspension. A pitch angle estimating section is provided for estimating the pitch angle of the vehicle body with respect to the road surface from a constant, storing the pitch angle in the pitch angle storage section, and outputting the pitch angle to an output section.

Further, the optical axis control device for a vehicle lamp according to the present disclosure includes:
The vehicle attitude angle estimation device and an optical axis control section that controls the optical axis of the vehicle lamp based on the pitch angle estimated by the vehicle attitude angle estimation device.

According to the vehicle posture angle estimating device of the present disclosure, it is possible to estimate the posture angle of the vehicle even during acceleration/deceleration of the vehicle or while the road surface gradient is changing.

Further, according to the optical axis control device of the vehicle lamp of the present disclosure, it is possible to appropriately control the optical axis of the vehicle lamp even when the vehicle is accelerating or decelerating or the road surface gradient is changing.

1 is a left side view of a vehicle having a vehicle body supported by suspensions; FIG. 1 is a configuration diagram of a vehicle attitude angle estimation device according to Embodiment 1; FIG. 1 is a configuration diagram of a vehicle attitude angle estimation device according to Embodiment 1; FIG. 1 is a configuration diagram of a vehicle attitude angle estimation device according to Embodiment 1; FIG. FIG. 10 is a configuration diagram of a static pitch angle estimator in Embodiment 2; 1 is a rear side view of a vehicle having a vehicle body supported by suspensions; FIG. FIG. 11 is a configuration diagram of a vehicle attitude angle estimation device according to Embodiment 5;

Hereinafter, the vehicle attitude angle estimation device of the present disclosure will be described according to each embodiment with reference to the drawings. In addition, in each embodiment, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted as appropriate.

Embodiment 1.
A vehicle attitude angle estimation device according to Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic diagram of a vehicle supported by a suspension on which a vehicle attitude angle estimation device according to Embodiment 1 is mounted. FIG. 2 is a block diagram showing the configuration of the vehicle posture angle estimating device according to the first embodiment.

As shown in FIG. 1, the vehicle 100 has a vehicle body 104 and wheels 107 . The wheels 107 are in contact with the road surface 103 and the left and right wheels 107 are connected by an axle 110 . A vehicle body 104 is attached to an axle 110 via a suspension 102 . Moreover, the road surface 103 has a slope 108 with respect to the horizontal plane. Further, in FIG. 1 , reference numeral 109 indicates the center of gravity of the vehicle 100 .

The vehicle 100 is provided with a vehicle attitude angle estimation device 101 , a headlamp 106 , an acceleration sensor 201 , an altitude sensor 202 and a vehicle speed sensor 203 . Acceleration sensor 201 is fixed to vehicle body 104 . The altitude sensor 202 is a sensor that detects the altitude of the vehicle, and may be, for example, a satellite positioning system. Alternatively, altitude sensor 202 may be a device that measures air pressure and converts it to altitude. The vehicle speed sensor 203 may be a sensor that obtains the vehicle speed from the rotation speed of the wheels 107, for example. Alternatively, the vehicle speed sensor 203 may be a device that estimates the speed of the vehicle from the image of the vehicle-mounted camera.

As shown in FIG. 2, the vehicle attitude angle estimation device 101 includes a static pitch angle estimation unit 205, a synthetic acceleration estimation unit 206, a pitch angle storage unit 208, and a pitch angle estimation unit 207.

The vehicle attitude angle estimation device 101 obtains at least vehicle acceleration information measured by the acceleration sensor 201, altitude information of the vehicle body 104 measured by the altitude sensor 202, and vehicle speed Using the vehicle speed information measured by the sensor 203 , the pitch angle 105 of the vehicle body 104 with respect to the road surface 103 is estimated and output to the output unit 204 . The output unit 204 may be, for example, the optical axis control unit 111 of the headlamp 106 . In this case, the optical axis controller 111 of the headlamp 106 may be configured to adjust the optical axis based on the pitch angle of the vehicle body estimated by the vehicle attitude angle estimation device 101 .

Based on at least acceleration information obtained from the acceleration sensor 201, altitude information obtained from the altitude sensor 202, vehicle speed information obtained from the vehicle speed sensor 203, and a constant determined by the suspension 102, the static pitch angle estimation unit 205 A static pitch angle is estimated, which is the pitch angle of the vehicle body 104 with respect to the road surface when the vehicle is not accelerating or decelerating on a flat road surface.

Synthetic acceleration estimator 206 uses the acceleration information obtained from acceleration sensor 201 and the static pitch angle estimated by static pitch angle estimator 205 to estimate the component of the acceleration applied to vehicle body 104 parallel to the vehicle traveling direction. calculate.

The pitch angle storage unit 208 stores the pitch angle of the vehicle body 104 with respect to the road surface estimated in the previous calculation cycle.

The pitch angle estimating unit 207 calculates the component parallel to the vehicle traveling direction of the acceleration applied to the vehicle body 104 estimated by the synthetic acceleration estimating unit 206 and the acceleration of the vehicle body 104 with respect to the road surface in the previous calculation cycle stored in the pitch angle storage unit 208. Using the pitch angle and a constant determined by the suspension, the pitch angle of the vehicle body 104 with respect to the road surface is estimated. Also, the estimated pitch angle is stored in the pitch angle storage unit 208 and output to the output unit 204 .

Next, the principle of pitch angle estimation in the vehicle attitude angle estimation device 101 of this embodiment will be described.

As shown in FIG. 1, a coordinate system fixed to the axle 110 is taken, with the direction of travel of the vehicle being the x-axis and the direction perpendicular to the road surface being the z-axis. Here, the wheels 107 are regarded as rigid bodies, and the axles 110 of the front and rear wheels are always parallel to the road surface 103 . At time t, the position of the vehicle center of gravity 109 in the coordinate system fixed to the axle 110 is p _0,t , its x coordinate is x _0,t , and its z coordinate is z _0,t .

The suspension 102 is a spring-damper system with a spring constant of k/4 and a damper coefficient of c/4, and the wheelbase of the vehicle is 2L. At this time, the pitch angle φ _t of the vehicle body with respect to the road surface at time t satisfies the angular motion equation expressed by the following equation (1).

where _Jy is the moment of inertia of the vehicle around the center of gravity, M is the mass of the vehicle, _d is the height of the center of gravity of the vehicle from the axle, θt is the road surface gradient 108 with respect to the horizontal plane, g is the acceleration of gravity, and _Vt is the vehicle speed.

φ _s is the pitch angle of the vehicle body 104 with respect to the road surface when the longitudinal acceleration V(dot) _t −gsin θ _t applied to the vehicle is zero. Although φ _s changes depending on cargo and passenger getting on and off, it does not change during running. More strictly speaking, it may change due to consumption of fuel or the like, but the change is sufficiently small, and φ _s can be regarded as constant for a short period of time. φ _s is referred to herein as the static pitch angle.

A position _Pt of the acceleration sensor 201 attached to the vehicle body 104 in the coordinate system fixed to the axle 110 is expressed by the following equation (2).

However, p0 _,t is the position of the center of gravity 109 of the vehicle in the coordinate system fixed to the axle 110, and r is the position of the acceleration sensor 201 when the position of the center of gravity of the vehicle p0 _,t is set as the origin in the coordinate system fixed to the vehicle body 104. is the position, and R _y (φ _t ) is the rotation matrix represented by the following equation.

Since the acceleration of the acceleration sensor is the second derivative of _pt , the following equation (3) holds.

Since the acceleration measured by the acceleration sensor is the value obtained by adding gravity and inertial force to its own acceleration, the acceleration measured by the acceleration sensor is expressed by the following formula (4) in a coordinate system fixed to the road surface. be.

However, G is the vertical upward gravitational acceleration vector, and F is the inertial force associated with vehicle acceleration/deceleration and gradient change, which is expressed by the following formula.

Since the acceleration sensor is fixed to the vehicle body, the measured value _Ot of the acceleration sensor is obtained by rotating the acceleration represented by the formula (4) by the pitch angle of the vehicle body, and is represented by the following formula (5). be done.

Since the x-axis direction of the suspension is constrained, the x component of the acceleration p(2 dots) _t of the acceleration sensor is zero. If the equation (5) is approximated assuming that the pitch angle φt of the vehicle body is very small, the _x component and the z component of the measurement value _Ot of the acceleration sensor are represented by the following equation (6).

Eliminating φ _t from Equation (6) using Equation (1), V (dot) _t − g sin θ _t and z (2 dots) _{0, t} − V _t θ (dot) _t +gcos θ _t are obtained by φ _s , It can be seen that it is determined as a function of φ (dot) _t and φ (2 dots) _t . Therefore, if these functions are set to u _t and w _t respectively, they are represented by the following equation (7). Here, u _t and w _t respectively correspond to the components parallel and perpendicular to the vehicle traveling direction of the acceleration applied to the vehicle.

However, in equation (7), φ _t is obtained by solving equation (1) with respect to φ _t and is a function of φ _s , φ(dot) _t , and φ(2 dots) _t .

Further, in the equation (7), values measured using an angular acceleration sensor or an angular velocity sensor (not shown) may be used as φ (dot) _t and φ (2 dots) _t . Alternatively, by placing the acceleration sensor 201 near the center of gravity 109 of the vehicle and setting r≈0, the terms relating to φ(dot) _t and φ(2 dots) _t may be eliminated from u _t and w _t . More preferably, a plurality of acceleration sensors or gyro sensors arranged at different positions of the vehicle may be used to calculate the acceleration near the center of gravity position p0 _,t of the vehicle. Alternatively, φ (dot) _t ≈ φ (2 dots) _t ≈ 0 may be approximated.

Now, the following formula (8) holds from formula (7).

In equation (8), V (dot) _t can be obtained from numerical differentiation of the vehicle speed V _t obtained from the vehicle speed sensor. Also, the right side of the equation (8) is equal to the altitude change. Therefore, by numerically differentiating the altitude h _t measured by the altitude sensor 202 and substituting it into the right side of the equation (8), the static pitch angle φ _s can be asked for.

However, since the numerical derivative V (dot) _t of vehicle speed and the numerical derivative h (dot) _t of altitude contain high-frequency errors accentuated by the numerical derivative, (8) at one time t The static pitch angle φ _s obtained from the equation also contains high frequency errors. Therefore, in the calculation according to the present embodiment, the static pitch angle φ _s is obtained by the nonlinear least-squares method using equation (8) at a plurality of times t. The nonlinear least-squares method may use a known optimization method such as the conjugate gradient method or the quasi-Newton method. Alternatively, a technique specialized for the nonlinear least squares method such as the Levenberg-Marquard method may be used.

Further, the numerical differentiation V (dot) _t of the vehicle speed and the numerical differentiation h (dot) _t of the altitude can be obtained, for example, by dividing the difference between the values at two consecutive times by the time between the two times. good to ask Alternatively, an incomplete differential filter may be used.

By substituting the static pitch angle φ _s estimated as described above and the acceleration O _t measured by the acceleration sensor 201 into the equation (7) and calculating u _t , the acceleration due to acceleration and deceleration of the vehicle and the gravitational acceleration component V(dot) _t −gsin θ _t parallel to the traveling direction of the road surface of the synthesized acceleration of .

Then, the component V(dot) _t −gsin θ _t parallel to the traveling direction of the road surface of the composite acceleration of the acceleration due to acceleration/deceleration of the vehicle and the gravitational acceleration is substituted into the equation (1). Furthermore, by solving the initial value problem of equation (1) using the pitch angle φ _t-1 and the pitch angular velocity φ (dot) _t-1 at time t-1, which is the previous calculation cycle, the pitch of the vehicle body with respect to the road surface The angle φ _t and the pitch angular velocity φ(dot) _t can be determined. For example, the Euler method may be used to solve the initial value problem. Alternatively, the Runge-Kutta method may be used. Also, the obtained pitch angle φ _t and pitch angular velocity φ (dot) _t may be stored in the storage unit for the next calculation cycle.

Next, the operation of the vehicle attitude angle estimation device 101 of this embodiment will be described.

The static pitch angle estimator 205 calculates at least the acceleration Ot measured by the acceleration sensor 201 at a plurality of times _t , the vehicle speed Vt measured by the vehicle speed sensor 203 at a plurality of times _t , and the altitude sensor 202. The static pitch angle φ _s is estimated based on the equation (8) from the altitudes h _t at a plurality of times t and the constants k and c determined by the suspension. Here, the coefficients k and c determined by the suspension may be stored in a storage unit (not shown).
Synthetic acceleration estimator 206 _calculates function _{u t} ₍ φ _s ; φ(dot ) _t , φ(2 dots) _t ), the component V(dot) _t −gsin θ _t parallel to the traveling direction of the road surface of the resultant acceleration due to acceleration/deceleration of the vehicle and gravitational acceleration is calculated.
The pitch angle estimating unit 207 stores the component V (dot) _t −gsin θ _t parallel to the traveling direction of the road surface of the synthetic acceleration of the acceleration due to acceleration/deceleration of the vehicle calculated by the synthetic acceleration estimating unit 206 and the gravitational acceleration, and a pitch angle storage unit. The pitch angle φ _t is calculated by solving the initial value problem of equation (1) using the previous calculation period stored by 208, for example, the pitch angle φ _t at time t-1, and the pitch angle storage unit 208 and output to the output unit 204 .

With the vehicle attitude angle estimation device according to this embodiment, it is possible to estimate the pitch angle of the vehicle body with respect to the road surface even when the vehicle is accelerating or decelerating or the gradient is changing.

In general, physical quantities such as acceleration and altitude changes are differential quantities of position, and high-frequency errors are inherently superimposed on the measured values. Operations such as integration and averaging are indispensable for accurately estimating gradients and pitch angles using such measured values. However, if operations such as integration and averaging are directly applied to the slope and pitch angle, it is necessary to assume that the changes in the road slope and vehicle pitch angle are sufficiently small and constant during the target period. However, during acceleration/deceleration of the vehicle or changes in the road surface gradient, the gradient and pitch angle change dynamically and cannot be regarded as constant. This is one of the reasons why the known method cannot estimate the attitude angle of the vehicle while the vehicle is accelerating or decelerating or while the road surface gradient is changing.

On the other hand, the vehicle attitude angle estimation device 101 of this embodiment does not directly apply the operation corresponding to the integration or averaging to the gradient or the pitch angle, but rather the static pitch angle which is an amount that does not change while driving. By applying it to φ _s , the above problem is solved, and it is possible to estimate the attitude angle of the vehicle in a situation where the vehicle is accelerating or decelerating or the gradient is changing. The vehicle attitude angle estimating device 101 of this embodiment can estimate the pitch angle φ _t of the vehicle body with respect to the road surface even when the vehicle is accelerating or decelerating or the road surface gradient is changing.

The vehicle attitude angle estimation device 101 described in the present embodiment is not limited to the one that uses Equation (1) as the angular motion equation of the pitch angle. As long as the pitch angle φ _t is a function of the static pitch angles φ _s , φ(dot) _t , and φ(2dot) _t , spring non-linearity and suspension geometry effects may be introduced.

In addition, in the vehicle attitude angle estimation device 101 described in this embodiment, the static pitch angle estimation unit 205 is not limited to performing static pitch angle estimation in all calculation cycles. Since the static pitch angle does not change during running, the static pitch angle estimating unit 205 estimates the static pitch angle once every N calculation cycles, where N is an integer, and the synthetic acceleration estimating unit 206 estimates The remaining calculations may be performed using the most recent static pitch angle obtained. As a result, even if the measurement cycle of the altitude sensor 202 is N times the measurement cycle of the other sensors, the vehicle attitude angle estimation device 101 according to the present embodiment can detect the pitch angle of the vehicle body without reducing the estimation cycle. can be estimated.

Furthermore, in the vehicle attitude angle estimation device 101 described in this embodiment, the pitch angle estimation unit 207 further uses the angular velocity of the pitch angle of the vehicle body measured by an angular velocity sensor such as a gyro sensor, for example, using a Kalman filter. You may estimate a pitch angle, removing a noise by . Accordingly, even when noise is superimposed on the acceleration sensor 201, the vehicle attitude angle estimation device 101 can accurately estimate the pitch angle.

In addition, the vehicle attitude angle estimation device 101 of this embodiment is combined with an optical axis control unit 111 that controls the optical axis of the vehicle lamp based on the pitch angle of the vehicle body with respect to the road surface estimated by the vehicle attitude angle estimation device 101. may constitute an optical axis control device for a vehicle lamp. This makes it possible to appropriately control the optical axis of the vehicle lamp so as not to dazzle the driver of the oncoming vehicle even when the vehicle is accelerating or decelerating or the gradient is changing.

Also, the functions of the static pitch angle estimating section, the synthetic acceleration estimating section, and the pitch angle estimating section in the vehicle posture angle estimating device of this embodiment may be realized by a processing circuit as shown in FIG. That is, the vehicle attitude angle estimation device may include a processing device for estimating the static pitch angle, estimating the synthesized acceleration, estimating the pitch angle, storing the estimated pitch angle in the pitch angle storage section, and outputting the estimated pitch angle to the output section. The processing circuit, even if it is dedicated hardware, is a CPU (Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, also called DSP).

When the processing circuit is dedicated hardware, the processing circuit corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. The functions of the static pitch angle estimating section, the synthetic acceleration estimating section, and the pitch angle estimating section may be realized individually by the processing circuit, or the functions of the respective sections may be collectively realized by the processing circuit.

When the processing circuit is a CPU, the functions of the static pitch angle estimator, synthetic acceleration estimator, and pitch angle estimator are realized by software, firmware, or a combination of software and firmware. Software and firmware are written as programs and stored in memory. The processing circuit implements the function of each part by reading and executing the program stored in the memory. That is, when the vehicle attitude angle estimation device is executed by the processing circuit, the step of estimating the static pitch angle, the step of estimating the resultant acceleration, the step of estimating the pitch angle, storing it in the pitch angle storage unit, and sending it to the output unit A memory is provided for storing the program that will result in the outputting step being executed. It can also be said that these programs cause a computer to execute the procedures and methods of the static pitch angle estimating section, the synthetic acceleration estimating section, and the pitch angle estimating section. Here, the memory corresponds to, for example, non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, EEPROM, magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD, etc. do.

It should be noted that the functions of the static pitch angle estimator, synthetic acceleration estimator, and pitch angle estimator may be partly implemented by dedicated hardware and partly implemented by software or firmware. For example, the function of the static pitch angle estimator is realized by a processing circuit as dedicated hardware, and the processing circuit reads and executes the program stored in the memory for the synthetic acceleration estimator and pitch angle estimator. It is possible to realize the function by

In this way, the processing circuit can implement each of the functions described above by means of hardware, software, firmware, or a combination thereof.

Embodiment 2.
101 A of vehicle attitude|position angle estimation apparatuses of this embodiment are the same as Embodiment 1 except a static pitch angle estimation part. The static pitch angle estimator 205A in the vehicle attitude angle estimator 101A of this embodiment will be described below with reference to FIG.

In this embodiment, the static pitch angle estimator 205A includes a constant term calculator 301, a differential coefficient calculator 302, a static pitch angle calculator 303, and a state storage 304.

A constant term calculation unit 301 calculates a first constant term independent of the static pitch angle among components parallel to the vehicle traveling direction of the acceleration applied to the vehicle body 104 from the acceleration information obtained from the acceleration sensor 201 .

From the acceleration information obtained from the acceleration sensor 201, the differential coefficient calculation unit 302 calculates the first proportionality coefficient with respect to the static pitch angle among the components parallel to the vehicle traveling direction of the acceleration applied to the vehicle body 104.

The state storage unit 304 stores at least the estimated value of the static pitch angle in the previous calculation cycle.

Static pitch angle calculator 303 calculates at least altitude information obtained from altitude sensor 202, vehicle speed information obtained from vehicle speed sensor 203, the first constant term calculated by constant term calculator 301, and differential coefficient calculation. Estimates the static pitch angle based on the first proportional coefficient calculated by the unit 302, the estimated value of the static pitch angle in the previous calculation cycle stored in the state storage unit 304, and the constant determined by the suspension. do. In addition, the estimated static pitch angle is stored in state storage section 304 and output to synthetic acceleration estimation section 206 .

Next, the principle of static pitch angle estimation in the static pitch angle estimation section 205A of the vehicle attitude angle estimation device 101A of this embodiment will be described.

In this embodiment, the component u _t (φ _s ; φ (dot) _t , φ (2 dots) _t ) of the acceleration applied to the vehicle body 104 parallel to the vehicle traveling direction is approximated by the first-order Taylor expansion. Since u _t (φ _s ; φ (dot) _t , φ (2 dots) _t ) is a function of the static pitch angle φ _s , it is represented by the following equation (9).

In Equation (9), values measured using an angular acceleration sensor or an angular velocity sensor (not shown) may be used as φ (dot) _t and φ (2 dots) _t . Alternatively, by placing the acceleration sensor 201 near the center of gravity 109 of the vehicle and setting r≈0, the terms relating to φ (dot) _t and φ (2 dots) _t may be eliminated from ut and wt. More preferably, a plurality of acceleration sensors or gyro sensors arranged at different positions on the vehicle may be used to calculate the acceleration near the center of gravity of the vehicle p0, _t . Alternatively, by assuming that pitch angle changes due to gradient changes and vehicle acceleration/deceleration are relatively smooth and ignoring high-frequency pitch angle changes resulting from suspension vibration modes, etc., φ (dot) t ≈ φ (2 dots) It may be approximated as t≈0.

Now, based on the approximation of formula (9), formula (8) can be transformed into formula (10) below.

Since the equation (10) is linear with respect to the static pitch angle φ _s to be estimated, the static pitch angle φ _s can be obtained by the linear least squares method. This eliminates the need for repetitive calculations required in the nonlinear least squares method, and determines the time required for calculation. This is a desirable property for real-time computation.

More desirably, the amount of computation can be further reduced by using an adaptive filter described below. Specifically, the left side of the equation (10) is set to Y _t and the right side to U ^T _t ·φ _s , and the calculation represented by the following equation (11) is executed every hour. Here, U ^T _t denotes the transposed matrix of U _t . By repeating the calculation of equation (11), φ _s,t converges to φ _s . This allows the static pitch angle φ _s to be obtained. Also, the determined static pitch angle φ _s may be stored in the storage section for the next calculation cycle.

However, _Mt is represented by the following formula (12).

In equations (11) and (12), λ _t is a predetermined constant called the forgetting factor, and represents how smoothly the static pitch angle φ _s can change. The forgetting factor may be a constant independent of time. Alternatively, it may be variable according to speed. By using the forgetting factor, the static pitch angle estimator 205 does not need to store acceleration, altitude, and vehicle speed at multiple times. Therefore, it is suitable for mounting on a microcontroller or the like with a limited memory capacity.

Next, the operation of the vehicle attitude angle estimation device 101A of this embodiment will be described.

Constant term calculator 301 calculates the first term on the right side of equation (9) from the acceleration _Ot measured by acceleration sensor 201 . The first term on the right side of equation (9) is a constant term that does not depend on the static pitch angle φ _s among the components u _t of the acceleration applied to the vehicle body 104 parallel to the vehicle traveling direction. In this specification, the constant term is also called a first constant term.
A differential coefficient calculation unit 302 calculates a coefficient part related to φ _s in the second term on the right side of equation (9) from the acceleration O _t measured by the acceleration sensor 201 . The coefficient is a proportionality coefficient related to the static pitch angle φ _s of the component u _t of the acceleration applied to the vehicle body 104 parallel to the vehicle traveling direction. This proportionality factor is also referred to herein as the first proportionality factor.
The static pitch angle calculator 303 calculates at least the vehicle speed Vt measured by the vehicle speed sensor 203, the altitude _ht _measured by the altitude sensor 202, the first constant term calculated by the constant term calculator 301, Based on the coefficient calculated by the differential coefficient calculation unit 302 and the static pitch angle φ _{s, t-1} and the vector Φ _t-1 one time ago stored by the state storage unit 304, the adaptive filter of formula (11) are used to calculate the static pitch angle φ _s,t and the vector Φ _t , which are stored in the state storage unit 304 and output to the resultant acceleration estimation unit 206 . Thereafter, the same processing as in Embodiment 1 is performed to estimate the pitch angle _φt of the vehicle body with respect to the road surface.

According to the vehicle attitude angle estimation device 101A according to the present embodiment, in addition to the effects described in the first embodiment, it is possible to further reduce the amount of calculation and realize processing more suitable for real-time processing.

It should be noted that the vehicle attitude angle estimation device 101A described in this embodiment is not necessarily limited to using the equation (11) as the adaptive filter. For example, an LMS (Least Mean Squares) filter or a total recursive least mean squares filter may be used as long as the static pitch angle φ _s can be obtained based on the equation (10).

Also in the present embodiment, the static pitch angle estimator 205A is not limited to static pitch angle estimation in all calculation cycles. Since the static pitch angle does not change during running, the static pitch angle estimator 205A estimates the static pitch angle once every N calculation cycles, where N is an integer, and the synthetic acceleration estimator 206 estimates The remaining calculations may be performed using the most recent static pitch angle obtained. As a result, even if the measurement period of the altitude sensor 202 is N times the measurement period of the other sensors, the pitch angle of the vehicle body can be estimated without dropping the estimation period.　　

Further, as in the first embodiment, the vehicle attitude angle estimation device 101A of the present embodiment and the optical axis of the vehicle lamp are controlled based on the pitch angle of the vehicle body with respect to the road surface estimated by the vehicle attitude angle estimation device 101A. It may be combined with the optical axis control unit 111 to form an optical axis control device for a vehicle lamp.

Further, as in the first embodiment, each function of the constant term calculator, the differential coefficient calculator, and the static pitch angle calculator in the static pitch angle estimator of the vehicle attitude angle estimation device of the present embodiment is implemented by a processing circuit. may be realized. That is, the static pitch angle estimator calculates the first constant term, calculates the first proportional coefficient, calculates the static pitch angle, stores it in the state storage unit, and outputs it to the synthetic acceleration estimator. may comprise a processor of The processing circuit may be dedicated hardware or may be a CPU executing a program stored in memory.

When the processing circuit is dedicated hardware, the processing circuit corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. The functions of the constant term calculation unit, differential coefficient calculation unit, and static pitch angle calculation unit may be realized individually by the processing circuit, or the functions of each unit may be collectively realized by the processing circuit.

When the processing circuit is a CPU, the functions of the constant term calculator, differential coefficient calculator, and static pitch angle calculator are realized by software, firmware, or a combination of software and firmware. Software and firmware are written as programs and stored in memory. The processing circuit implements the function of each part by reading and executing the program stored in the memory. That is, the vehicle attitude angle estimator, when executed by the processing circuit, calculates a first constant term, calculates a first proportional coefficient, calculates a static pitch angle and stores it in the state storage unit. and a memory for storing a program that results in execution of the step of outputting to the synthesized acceleration estimating unit. It can also be said that these programs cause a computer to execute the procedures and methods of the constant term calculator, the differential coefficient calculator, and the static pitch angle calculator.

It should be noted that the functions of the constant term calculator, the differential coefficient calculator, and the static pitch angle calculator may be partly implemented by dedicated hardware and partly implemented by software or firmware. For example, the function of the constant term calculator and the differential coefficient calculator is realized by a processing circuit as dedicated hardware, and the static pitch angle calculator reads and executes a program stored in the memory. It is possible to realize the function by

Embodiment 3.
A vehicle attitude angle estimation device 101B in this embodiment has the same basic configuration as that in the first embodiment, but differs in that the roll angle of the vehicle body is considered. Specifically, of the measured value Ot measured by the acceleration sensor, the _y component is considered in addition to the x component and z component. In other words, the orthogonal three-axis components are considered.

FIG. 6 is a rear side view of a vehicle having a vehicle body supported by suspensions. As shown in FIG. 6, coordinates fixed to the axle 110 with the direction of travel of the vehicle as the x-axis, the direction perpendicular to the road surface as the positive z-axis, and the direction perpendicular to the x- and z-axes as the y-axis. take the system The suspension 102 is a spring-damper system with a spring constant of k/4 and a damper coefficient of c/4, and the width between the left and right wheels is 2W. At this time, the roll angle ψ _t of the vehicle with respect to the road surface 103 at time t satisfies the angular motion equation expressed by the following equation (13).

where ψ _t is the roll angle of the vehicle body with respect to the road surface, ψ _s is the static roll angle, η _t is the bank angle 402 of the road surface with respect to the horizontal plane, χ (dot) _t is the yaw rate, and V _t χ (dot) _t is the lateral inertial force in a coordinate system fixed to the axle 110;

When the pitch angle φ _t and the roll angle ψ _t of the vehicle body with respect to the road surface are very small, the measured value O _t measured by the acceleration sensor is approximately represented by the following equation (14).

Eliminating φ _t and ψ _t from equation (14) using equations (1) and (13) yields V(dot) _t −gsin θ _t , y(2 dots) _{0, t} +V _t χ(dot) _t +g sin η _t cos θ _t and z(2 dots) _0,t −V _t θ(dots) _t +g cos η _t cos θ _t are determined as functions of φ _s and φ(dots) _t , φ(2 dots) _t . Therefore, if these functions are set to u _t , v _t , and w _t respectively, they are represented by the following equation (15).

However, in equation (15), φ _t is obtained by solving equation (1) with respect to φ _t and is a function of φ _s , φ(dot) _t and φ(2 dots) _t . Similarly, ψ _t is the solution of Equation (13) with respect to ψt, and is a function of ψ _s , ψ(dot) _t and ψ(2dot) _t .

The dynamic roll angle of the car body can be estimated from the lateral acceleration applied to the car body and the characteristics of the suspension, but the static roll angle of the car body cannot be distinguished from the bank angle of the road surface and the accelerometer installed in the car body. I don't get it. Therefore, even if the static roll angle ψ _s is set to a minute predetermined value, preferably 0, it does not affect other estimated values such as the pitch angle of the vehicle body. Therefore, in this embodiment, the static roll angle ψ _s of the vehicle body is set to 0 or a predetermined value.

In equation (15), φ (dot) _t , ψ (dot) _t , φ (2 dots) _t and ψ (2 dots) _t are measured using an angular velocity sensor such as a gyro sensor or an angular acceleration sensor (not shown). values can be used. Alternatively, by placing the acceleration sensor 201 near the center of gravity 109 of the vehicle and setting r≈0, φ (dot) _t , ψ (dot) _t , φ (2 dots) _t and ψ from u _t , v _t , and w _t (2 dots) You may eliminate the term for _t . More preferably, the acceleration near the center of gravity 109 of the vehicle may be calculated using a plurality of acceleration sensors or gyro sensors arranged at different positions on the vehicle. Alternatively, by assuming that changes in pitch and roll angles due to gradient changes and vehicle acceleration/deceleration are relatively smooth, and ignoring high-frequency pitch and roll angle changes due to suspension vibration modes, etc., It may be approximated as φ (dot) _t ≈ψ (dot) _t ≈φ (2 dots) _t ≈ψ (2 dots) _t ≈0.

In the vehicle _posture angle _estimation device _101B of the present embodiment, _u Using _t (φ _s , φ _s ; φ (dot) _t , φ (dot) _t , φ (2 dots) _t , φ (2 dots) _t ), the equation (8) is used as in the first embodiment. The static pitch angle φ _s can be obtained by the non-linear least squares method. Alternatively, as in the second embodiment, the static pitch angle φ _s can be obtained by a linear least squares method using equation (10) or an adaptive filter using equation (11). After obtaining the static pitch angle φ _s , the pitch angle φ _t of the vehicle body with respect to the road surface can be obtained in the same manner as in the first embodiment.

When the acceleration sensor 201 is fixed to the vehicle body 104 and the vehicle body 104 rolls, the z component of the acceleration applied to the acceleration sensor 201 is divided into the z component and the _y component of the measured value Ot. Furthermore, centrifugal force is superimposed while traveling on a curved road. Therefore, when the vehicle body 104 is rolling or traveling on a curved road, the attitude angle of the vehicle body 104 cannot be correctly estimated unless the y component is considered. On the other hand, according to the vehicle attitude angle estimation device 101B of the present embodiment, since the _y component of the measurement value Ot of the acceleration sensor is taken into account, the vehicle body 104 is rolling or passing through a curved road. Even in the case of , the attitude angle can be estimated correctly.

Note that the vehicle attitude angle estimation device 101B described in this embodiment is not limited to using equation (13) as the equation of angular motion for the roll angle. As long as the roll angle φ _t is a function of φ _s , φ(dot) _t and φ(2dot) _t , spring non-linearities, suspension geometry effects, etc. may be introduced. Also, since the yaw rate χ (dot) _t is usually sufficiently smaller than the pitch angular velocity and the roll angular velocity, the term related to the yaw rate is ignored in the acceleration of the acceleration sensor with respect to the center of gravity in the equation (15). It is also permissible to use the measured value as the yaw rate.

Further, as in the first embodiment, the vehicle attitude angle estimation device 101B of the present embodiment and the optical axis of the vehicle lamp are controlled based on the pitch angle of the vehicle body with respect to the road surface estimated by the vehicle attitude angle estimation device 101B. It may be combined with the optical axis control unit 111 to form an optical axis control device for a vehicle lamp.

Embodiment 4.
A vehicle attitude angle estimation device 101C in this embodiment has the same basic configuration as in the first embodiment, but differs in that an error of the vehicle speed sensor 203 is considered.

When using the principle of multiplying the rotational angular velocity of the wheel by the wheel radius as the measurement principle of the vehicle speed sensor 203, if the wheel radius has an error due to wear of the wheel or a decrease in air pressure, the measured vehicle speed also has an error. have. Therefore, the vehicle speed measured by the vehicle speed sensor 203 is defined as V0 _,t , and the true vehicle speed Vt is represented by the following _equation (16).

Here, κ is a parameter that represents the wheel radius error and does not change in a short period of time. At this time, the equation (8) is expressed as the following equation (17).

In the vehicle attitude angle estimating device 101C of the present embodiment, the static pitch angle φ _s is obtained in the same manner as in the first embodiment by using the equation (17) instead of the equation (8) used in the first embodiment. can be done. Specifically, in the equation (17), the static pitch angles _φs and κ are obtained simultaneously by the nonlinear least-squares method using the static pitch angles _φs and κ as variables. After obtaining the static pitch angle φ _s , the same processing as in the first embodiment can be performed to estimate the pitch angle φ _t of the vehicle body with respect to the road surface.

Similarly, by using the following formula (18) instead of formula (10), the adaptive filter described in the second embodiment can be configured. Further, it may be combined with the third embodiment.

According to the vehicle attitude angle estimating device 101C of this embodiment, the pitch angle can be accurately estimated even when the measured value of the vehicle speed sensor 203 has an error due to the wheel radius error.

In the vehicle attitude angle estimation device 101C described in this embodiment, the vehicle speed sensor 203 may be, for example, one that multiplies the rotational speed of one wheel by the wheel radius, or the average rotational speed of a plurality of wheels. may be multiplied by the wheel radius.

Further, as in the first embodiment, the vehicle attitude angle estimation device 101C of the present embodiment and the optical axis of the vehicle lamp are controlled based on the pitch angle of the vehicle body with respect to the road surface estimated by the vehicle attitude angle estimation device 101C. It may be combined with the optical axis control unit 111 to form an optical axis control device for a vehicle lamp.

Embodiment 5.
A vehicle attitude angle estimation device 101D according to this embodiment will be described with reference to FIG.
As shown in FIG. 7, a vehicle attitude angle estimation device 101D in this embodiment includes a coefficient storage unit 501, a pitch angular velocity estimation unit 502, and a coefficient prediction unit 503 in addition to the vehicle attitude angle estimation device 101 of the first embodiment. .

The coefficient storage unit 501 stores a second constant term that does not depend on the static pitch angle and a second proportional coefficient to the static pitch angle of the pitch angular velocity of the vehicle body.

The pitch angular velocity estimating unit stores the second constant term in the previous calculation cycle stored in the coefficient storage unit 501, the second proportionality coefficient in the previous calculation cycle, and the present time estimated by the static pitch angle estimating unit 205. The pitch angular velocity is estimated based on the estimated value of the static pitch angle in the calculation period of .

The coefficient prediction unit calculates the second constant in the next calculation cycle from the acceleration information obtained from the acceleration sensor 201, the pitch angle estimated by the pitch angle estimation unit 207, and the pitch angular velocity estimated by the pitch angular velocity estimation unit 502. The term and the second proportional coefficient are predicted and stored in the coefficient storage unit 501 .

Also, the static pitch angle estimator 205 is determined by acceleration information obtained from the acceleration sensor 201 provided in the vehicle body 104, at least altitude information obtained from the altitude sensor 202, vehicle speed information obtained from the vehicle speed sensor 203, and the suspension. A static pitch angle is estimated based on the constant plus a second constant term and a second proportionality factor.

Next, the principle of pitch angle estimation in the vehicle attitude angle estimation device 101D of this embodiment will be described. First, the equation (6) is transformed into the following equation (19).

From equation (19), it can be seen that V(dot) _t −gsin θ _t and z(2 dots) _{0, t} −V _t θ(dot) _t +gcos θ _t are linear with respect to φ(2 dots) _t . Therefore, the following formula (20) holds.

Using the inverse matrix lemma here, the following equation (21) holds.

Therefore, the following formula (22) holds.

For simplicity, the right side of formula (22) is written as the following formula.

By substituting equation (22) into equation (1), the differential equation expressed by equation (23) below is obtained.

(23) By solving the initial value problem of the equation, for example, by the Euler method, the pitch angular velocity φ (dot) _t at time t is obtained from the pitch angle φ _t-1 and the pitch angular velocity φ (dot) _t-1 one time ago. , can be predicted in the form of the following equation (24), which is a linear expression with respect to the static pitch angle φ _s .

In the equation (24) representing the pitch angular velocity φ (dot) _t , S _0,t is a constant term that does not depend on the static pitch angle φ _s , and S _1,t is a coefficient applied to the static pitch angle φ _s . . S _0,t is also referred to herein as the second constant term and S _1,t as the second proportionality factor.

Furthermore, by substituting equation (24) into equation (23) at time t, pitch angular acceleration φ(2 dots) _t at time t is determined as a function of static pitch angle φ _s . This is expressed as the following formula (25).

Substituting equations (24) and (25) into equation (19) and then eliminating φ _t using equation (1) yields V(dot) _t −gsin θ _t and z(2 dots) _0,t − V _t θ(dot) _t +gcos θ _t is determined as a function of φ _s . As a result, φ _s can be estimated using the nonlinear least-squares method using equation (8) as in the first embodiment.

Next, the operation of the vehicle attitude angle estimation device 101D of this embodiment will be described.
The coefficient storage unit 501 stores constant terms _S _0,tk and proportional coefficients S _1,tk of the pitch angular velocity at a plurality of times t ₁ , . . . , t _k , . do.
The static pitch angle estimating unit 205 calculates at least the constant term S _0,tk and the proportional coefficient S _1,tk at a plurality of times stored in the coefficient storage unit 501, and the acceleration at a plurality of times measured by the acceleration sensor 201. , the static pitch angle φ _s is estimated from the vehicle speed at a plurality of times measured by the vehicle speed sensor 203 and the altitude at a plurality of times measured by the altitude sensor 202 .
_Pitch angular velocity _estimator ₅₀₂ calculates ( 24) Calculate the pitch angular velocity φ (dot) _t using the formula.
_Coefficient _prediction unit 503 calculates ( 23) By solving the initial value problem of the equation, for example, by the Euler method, the constant term S _0,t+1 and the proportional coefficient S _1,t+1 at time t+1, which is the next calculation cycle, are predicted and stored in the coefficient storage unit 501 .

According to the vehicle posture angle estimating apparatus of the present embodiment, in addition to the effects described in the first embodiment, the pitch angle of the vehicle body derived from the vibration mode of the suspension 102 can also be estimated without using an additional sensor such as a gyro sensor. can. The vehicle attitude angle estimation device in this embodiment may also be combined with Embodiments 2 to 4 of the present disclosure, in which case the effects described in this embodiment are achieved in addition to the effects described in Embodiments 2 to 4. can.

Further, as in the first embodiment, the functions of the pitch angular velocity estimator, the coefficient predictor, the static pitch angle estimator, the synthetic acceleration estimator, and the pitch angle estimator in the vehicle attitude angle estimation device of the present embodiment are the processing It may be implemented by a circuit. That is, the vehicle attitude angle estimation device estimates the pitch angular velocity based on the second constant term and the second proportional coefficient stored in the coefficient storage unit and the estimated static pitch angle, The second constant term and the second proportional coefficient are predicted and stored in the coefficient storage unit, and the static pitch angle is estimated using the second constant term and the second proportional coefficient in addition to the measured values of each sensor. and a processing device for estimating the synthesized acceleration, estimating the pitch angle, storing it in the pitch angle storage unit, and outputting it to the output unit. A processing circuit, even if it is dedicated hardware, is a CPU that executes programs stored in memory may be

When the processing circuit is dedicated hardware, the processing circuit corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. The functions of the pitch angular velocity estimator, the coefficient predictor, the static pitch angle estimator, the synthetic acceleration estimator, and the pitch angle estimator may each be implemented by a processing circuit, or the functions of each unit may be collectively implemented by the processing circuit. It can be realized.

When the processing circuit is a CPU, the functions of the pitch angular velocity estimator, coefficient predictor, static pitch angle estimator, synthetic acceleration estimator, and pitch angle estimator are realized by software, firmware, or a combination of software and firmware. be. Software and firmware are written as programs and stored in memory. The processing circuit implements the function of each part by reading and executing the program stored in the memory. That is, when the vehicle attitude angle estimation device is executed by the processing circuit, the pitch angular velocity a step of estimating a second constant term and a second proportionality factor in the next calculation cycle and a step of storing the second constant term and the second proportionality factor in the coefficient storage unit; A program that results in the steps of estimating the static pitch angle using the coefficient, estimating the resultant acceleration, estimating the pitch angle, storing it in the pitch angle storage unit, and outputting it to the output unit. a memory for storing the It can also be said that these programs cause a computer to execute the procedures and methods of the pitch angular velocity estimator, the coefficient predictor, the static pitch angle estimator, the synthetic acceleration estimator, and the pitch angle estimator.

The functions of the pitch angular velocity estimator, coefficient predictor, static pitch angle estimator, synthetic acceleration estimator, and pitch angle estimator are partly realized by dedicated hardware and partly by software or firmware. It may be realized. For example, the function of the static pitch angle estimator is realized by a processing circuit as dedicated hardware, and the processing circuits of the pitch angular velocity estimator, coefficient predictor, synthetic acceleration estimator, and pitch angle estimator are stored in memory. The function can be realized by reading out and executing the stored program.

It should be noted that, within the scope of the present disclosure, it is possible to freely combine each embodiment and modifications, and to modify or omit each embodiment and modifications as appropriate.

Although the present disclosure has been described in detail, the above description, in all its aspects, is illustrative and the present disclosure is not limited thereto. It is understood that numerous variations not illustrated are contemplated without departing from the scope of the present disclosure.

101, 101A, 101B, 101C, 101D vehicle attitude angle estimation device,
111 optical axis control unit,
205, 205A static pitch angle estimator,
206 synthetic acceleration estimator,
207 pitch angle estimator,
208 pitch angle storage unit,
301 constant term calculator,
302 differential coefficient calculator,
303 static pitch angle calculator,
304 state storage unit,
501 coefficient storage unit,
502 pitch angular velocity estimator,
503 coefficient prediction unit

Claims

In a vehicle having a vehicle body supported from the road surface by a suspension, at least acceleration information obtained from an acceleration sensor provided on the vehicle body, altitude information obtained from an altitude sensor, vehicle speed information obtained from a vehicle speed sensor, and the suspension. a static pitch angle estimation unit that estimates a static pitch angle, which is the pitch angle of the vehicle body with respect to the road surface, when the vehicle is not accelerating or decelerating on a flat road surface, based on a determined constant;
a synthetic acceleration estimating unit for estimating a component of the acceleration applied to the vehicle body parallel to the traveling direction of the vehicle from at least the acceleration information and the static pitch angle estimated by the static pitch angle estimating unit;
a pitch angle storage unit that stores the pitch angle of the vehicle body relative to the road surface in the previous calculation cycle;
At least the component parallel to the direction of travel of the vehicle of the acceleration applied to the vehicle body estimated by the synthetic acceleration estimation unit, the pitch angle of the vehicle body with respect to the road surface in the previous calculation cycle stored in the pitch angle storage unit, and the suspension a pitch angle estimating unit that estimates the pitch angle of the vehicle body with respect to the road surface from a constant determined by, stores it in the pitch angle storage unit, and outputs it to an output unit;
A vehicle attitude angle estimation device with
The static pitch angle estimator,
a constant term calculation unit that calculates a first constant term that does not depend on the static pitch angle, among the components of the acceleration applied to the vehicle body that are parallel to the traveling direction of the vehicle, from the acceleration information obtained from the acceleration sensor;
a differential coefficient calculation unit that calculates a first proportional coefficient with respect to a static pitch angle among components of the acceleration applied to the vehicle body parallel to the traveling direction of the vehicle from acceleration information obtained from the acceleration sensor;
a state storage unit that stores at least the estimated value of the static pitch angle in the previous calculation cycle;
At least altitude information obtained from the altitude sensor, vehicle speed information obtained from the vehicle speed sensor, a first constant term calculated by the constant term calculator, a first proportional coefficient calculated by the differential coefficient calculator, and static pitch angle calculation for estimating a static pitch angle based on a constant determined by the suspension, storing the obtained static pitch angle estimated value in the state storage unit, and outputting it to the synthetic acceleration estimating unit. and
The vehicle posture angle estimating device according to claim 1.
The static pitch angle estimator includes at least acceleration information obtained from an acceleration sensor provided on the vehicle body, altitude information obtained from an altitude sensor, vehicle speed information obtained from a vehicle speed sensor, and a constant determined by the suspension, estimating a static pitch angle based on pitch angular velocity information obtained from an angular velocity sensor;
The vehicle attitude angle estimation device according to claim 1 or 2.
a coefficient storage unit that stores a second constant term that does not depend on the static pitch angle and a second proportional coefficient to the static pitch angle of the pitch angular velocity of the vehicle body;
estimating a pitch angular velocity based on at least the second constant term and the second proportional coefficient stored in the coefficient storage unit and the static pitch angle estimated by the static pitch angle estimating unit; a pitch angular velocity estimator;
From acceleration information obtained from the acceleration sensor, the pitch angle estimated by the pitch angle estimation unit, and the pitch angular velocity estimated by the pitch angular velocity estimation unit, the second constant term and the second a coefficient prediction unit that predicts a proportional coefficient of 2 and stores it in the coefficient storage unit;
The static pitch angle estimator includes at least acceleration information obtained from an acceleration sensor provided on the vehicle body, altitude information obtained from an altitude sensor, vehicle speed information obtained from a vehicle speed sensor, and a constant determined by the suspension, estimating a static pitch angle based on the second constant term and the second proportionality factor;
The vehicle attitude angle estimation device according to claim 1 or 2.
The static pitch angle estimating unit estimates the static pitch angle by considering orthogonal three-axis components of acceleration information obtained from an acceleration sensor provided on the vehicle body.
The vehicle attitude angle estimation device according to any one of claims 1 to 4.
The static pitch angle estimator estimates a static pitch angle and estimates an error in vehicle speed information obtained from the vehicle speed sensor.
The vehicle attitude angle estimation device according to any one of claims 1 to 5.
A vehicle attitude angle estimation device according to any one of claims 1 to 6;
an optical axis control unit that controls an optical axis of a vehicle lamp based on the pitch angle estimated by the vehicle attitude angle estimation device;
An optical axis control device for a vehicle lamp.