JP5039349B2 - Saddle-type vehicle attitude detection device, engine control device, and saddle-type vehicle - Google Patents

Description

  The present invention relates to an attitude detection device that detects the attitude of a vehicle using an acceleration sensor, an engine control apparatus that controls an engine based on the detected attitude of the vehicle, and a straddle-type vehicle equipped with the engine control apparatus.

Conventionally, an acceleration sensor that detects acceleration in two directions has been provided, the acceleration component of gravity acceleration in the vertical direction (height direction) and the horizontal direction (width direction) of the vehicle is detected, and the vehicle is tilted in the horizontal direction Has proposed a device that detects the roll angle based on these acceleration components by utilizing the fact that these acceleration components change together in accordance with the inclination angle (roll angle) (for example, Patent Documents). 1). Conventionally, such a device is used as a fall detection device that determines whether or not the vehicle has fallen based on the detected roll angle.
JP 2004-93537 A

  By the way, in a saddle riding type vehicle such as a motorcycle, there is a demand for detecting not only a roll angle but also a pitch angle (an inclination of a longitudinal axis of the vehicle). For example, there is a demand to control the output of the engine according to the pitch angle of the vehicle, such as a motorcycle used for a wheelie traveling that travels on a steep cliff or travels with the front wheels away from the road surface. .

  As a method of detecting the pitch angle of the vehicle, a method of detecting the acceleration component in the front-rear direction of the vehicle, calculating the ratio of the acceleration component in the front-rear direction to the gravitational acceleration, and detecting the pitch angle based on the ratio is considered. It is done.

  However, in addition to the sensors that detect the acceleration in the vertical direction and the horizontal direction that are conventionally provided, in addition to a sensor that detects the acceleration in the front-rear direction, or a new sensor that detects the acceleration in the three directions The cost will increase by that amount. Further, it may be difficult to secure a space for installing the sensor.

  The present invention has been made in view of the above problems, and its purpose is an attitude capable of detecting the pitch angle of a vehicle without directing the detection direction of an acceleration sensor for detecting acceleration in two directions in the front-rear direction of the vehicle. An object of the present invention is to provide a detection device, an engine control device that controls an engine based on a pitch angle, and a straddle-type vehicle.

  In order to solve the above problems, an attitude detection device according to the present invention includes an acceleration component of gravitational acceleration in a first direction determined in a direction different from the front-rear direction of the vehicle, the front-rear direction, and the first direction. Comprises acceleration detecting means for detecting an acceleration component of gravitational acceleration in a second direction defined in different directions, and pitch angle detecting means for calculating a value corresponding to the pitch angle of the vehicle. Then, the pitch angle detection means uses the acceleration component in the first direction and the acceleration component in the second direction, and a projection component of gravity acceleration in a plane perpendicular to the front-rear direction of the vehicle, and gravity acceleration Is calculated as a value corresponding to the pitch angle. According to the present invention, the pitch angle of a vehicle can be detected without newly installing a sensor for detecting an acceleration component in the front-rear direction.

  In one embodiment of the present invention, the first direction and the second direction may be orthogonal to each other. According to this aspect, it is possible to calculate the ratio between the gravitational acceleration and the projected component of the gravitational acceleration in a plane perpendicular to the front-rear direction of the vehicle with simpler processing. In this aspect, the first direction may be the left-right direction of the vehicle. The second direction may be the vertical direction of the vehicle. Thereby, the calculation process can be further simplified.

  In another aspect of the present invention, the acceleration detection means includes a noise extraction means for extracting a noise signal from a detection signal, and a signal obtained by subtracting the noise signal extracted by the noise extraction means from the detection signal. Subtracting means for outputting as a signal corresponding to the acceleration component. According to this aspect, the accuracy of posture detection is improved.

  In this aspect, the noise extraction means may be a high-pass filter circuit. Thereby, the phase delay of the signal due to passing through the filter circuit can be suppressed, and the time required for posture detection can be shortened.

  The engine control apparatus according to the present invention controls the engine based on the value corresponding to the pitch angle of the vehicle detected by the attitude detection apparatus. According to the present invention, the pitch angle of the vehicle can be detected without newly installing a sensor for detecting the acceleration component in the front-rear direction, and the engine can be controlled based on the pitch angle.

  A straddle-type vehicle according to the present invention is equipped with the engine control device. According to the present invention, the pitch angle of the vehicle can be detected without newly installing a sensor for detecting the acceleration component in the front-rear direction, and the engine can be controlled based on the pitch angle. Here, the straddle-type vehicle is, for example, a motorcycle (including a scooter), a four-wheel buggy, a snowmobile, or the like.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a motorcycle 1 equipped with an attitude detection apparatus 10 according to an embodiment of the present invention and an engine control apparatus 20 including the attitude detection apparatus 10.

  As shown in FIG. 1, the motorcycle 1 includes an attitude detection device 10, an engine control device 20, a vehicle body frame 3, and an engine unit 26.

  The vehicle body frame 3 has a steering head portion 3 a that supports the steering shaft 4 at a front end portion thereof. The vehicle body frame 3 extends obliquely downward from the steering head portion 3 a, then bends and extends below the seat 6. Thereafter, the vehicle body frame 3 extends obliquely from below the seat 6 toward the rear of the vehicle.

  An engine unit 26 is disposed at the rear of the vehicle. The engine unit 26 is a unit swing type, and moves up and down together with the rear wheel 5 with the pivot shaft 9 as a fulcrum. The engine unit 26 includes an engine 26 a having a cylinder 26 c and the like, and a driving force transmission mechanism 26 b that transmits the driving force output from the engine 26 a to the rear wheel 5. The engine 26a includes a spark plug 21 that burns a fuel / air mixture supplied to the cylinder 26c.

  An air cleaner 23 is disposed above the engine unit 26. The purified air that has passed through the air cleaner 23 flows through an intake passage constituted by an intake pipe 24 and a throttle body 25, and is supplied to the engine 26a. An injector 22 for injecting fuel into the intake passage is attached to the throttle body 25.

  Here, the attitude detection device 10 is disposed slightly below the steering head 3 a and is supported by the vehicle body frame 3. In addition, the arrangement position of the attitude | position detection apparatus 10 is not restricted to this. For example, it may be disposed below the seat 6 and supported by the body frame 3.

  Here, the engine control device 20 will be described. FIG. 2 is a block diagram showing the configuration of the engine control device 20. The engine control device 20 includes a posture detection device 10, an injector 22, and a spark plug 21, and the posture detection device 10 includes a control circuit 11, a storage device 12, and an acceleration detection device 16. The acceleration detection device 16 includes an acceleration sensor 13, an A / D conversion circuit 14, a high-pass filter circuit 15a, a phase compensation circuit 15b, and a subtraction circuit 15c. The high-pass filter circuit 15a, the phase compensation circuit 15b, and the subtraction circuit 15c constitute a noise removal circuit 15 and will be described here as an analog circuit.

  The control circuit 11 includes a CPU (Central Processing Unit), executes a program stored in the storage device 12, and controls various electrical components mounted on the vehicle. For example, the control circuit 11 controls the ignition timing of the spark plug 21 and the amount of fuel injected by the injector 22 according to the driving state of the vehicle. In the present embodiment, the control circuit 11 performs processing for detecting the attitude of the vehicle based on the signal output from the acceleration sensor 13, and based on the detected attitude, the ignition timing of the spark plug 21 and the injector 22 Control the amount of fuel injection. The processing executed by the control circuit 11 will be described later.

  The storage device 12 includes a volatile memory and a nonvolatile memory, and holds a program executed by the control circuit 11.

  The acceleration sensor 13 is an acceleration sensor using a semiconductor, such as a capacitance type acceleration sensor or an acceleration sensor using a piezoelectric element, and outputs a voltage signal corresponding to acceleration in two orthogonal directions. The acceleration sensor 13 is arranged so that the detection directions thereof are the vertical direction (height direction) and the left-right direction (vehicle width direction) of the vehicle, and a signal corresponding to the acceleration component of the gravitational acceleration in each direction is subtracted. 15c and the high-pass filter circuit 15a.

  In this example, the acceleration sensor 13 is described as an acceleration sensor using a semiconductor, but may be, for example, a pendulum type acceleration sensor. The acceleration sensor 13 may be two uniaxial sensors instead of the biaxial sensor that detects acceleration in two directions. In this case, the two single-axis sensors are installed so that the detection directions are the vertical direction and the front-rear direction of the vehicle.

  The noise removal circuit 15 extracts a noise signal (a signal generated by vibration of the vehicle, vibration of the engine 26a, etc.) included in the signal from the signal input from the acceleration sensor 13. Then, a signal obtained by subtracting the noise signal from the signal input from the acceleration sensor 13 is output to the A / D conversion circuit 14 as an acceleration signal. Hereinafter, each circuit constituting the noise removal circuit 15 will be described.

  The high-pass filter circuit 15 a extracts a noise signal from the signal input from the acceleration sensor 13. That is, the high-pass filter circuit 15a attenuates a signal having a frequency lower than a predetermined cutoff frequency in the signal input from the acceleration sensor 13, and passes a signal having a frequency higher than the cutoff frequency. A high-frequency signal that passes through the high-pass filter circuit 15a is input to the phase compensation circuit 15b. In general, a noise signal due to vibration of the engine 26a or the like has a higher frequency than a signal that fluctuates due to a change in the attitude of the vehicle. Here, the cut-off frequency is set lower than the frequency of the noise signal and higher than the frequency of the signal indicating the change in the attitude of the vehicle, and the high-pass filter circuit 15a outputs a noise signal.

  The phase compensation circuit 15b compensates for a phase shift of a signal generated by passing through the high pass filter circuit 15a. For example, when the high-pass filter circuit 15a advances the phase of the signal passing through the circuit by a predetermined phase difference, the phase compensation circuit 15b changes the phase of the signal input from the high-pass filter circuit 15a to the predetermined signal. It is delayed by the phase difference and output to the subtraction circuit 15c.

  The subtraction circuit 15c subtracts the noise signal input from the phase compensation circuit 15b from the signal output from the acceleration sensor 13, and outputs the obtained signal to the A / D conversion circuit 14 as an acceleration signal. The A / D conversion circuit 14 converts the analog acceleration signal input from the subtraction circuit 15 c into a digital signal and outputs the digital signal to the control circuit 11.

  3A shows an example of a signal output from the acceleration sensor 13, FIG. 3B shows an example of a noise signal output from the phase compensation circuit 15b, and FIG. 3C shows a subtraction circuit 15c. 2 shows an example of an acceleration signal output by. Further, here, an example will be described in which the vertical component of the gravitational acceleration gradually decreases as the vehicle tilts when the vehicle starts wheelie traveling or the like.

  As shown in FIG. 3A, the signal corresponding to the vertical acceleration component output from the acceleration sensor 13 gradually decreases as time elapses, and the frequency generated by the vibration of the engine 26a or the vibration of the vehicle. High noise signal is included.

  As described above, the high-pass filter circuit 15a suppresses a signal having a low frequency included in a signal input from the acceleration sensor 13, and allows only a noise signal having a high frequency to pass therethrough. As a result, FIG. 3B shows only a noise signal having a high frequency.

  Further, as described above, the subtraction circuit 15c subtracts the noise signal input from the phase compensation circuit 15b from the signal input from the acceleration sensor 13, and outputs the obtained signal as an acceleration signal. Therefore, FIG. 3C shows an acceleration signal having a low frequency indicating the vertical component of the gravitational acceleration. In the figure, the acceleration signal gradually decreases with the passage of time, indicating that the pitch angle (inclination of the longitudinal axis) increases as the vehicle inclines.

  Here, processing executed by the control circuit 11 will be described. The control circuit 11 detects vertical and horizontal acceleration components based on the acceleration signal input from the A / D conversion circuit 14, and based on the acceleration components, the value corresponding to the pitch angle of the vehicle (hereinafter referred to as the vehicle pitch angle). , The pitch angle corresponding value) is calculated. Based on the pitch angle corresponding value, the ignition timing of the engine 26a by the spark plug 21, the fuel injection amount by the injector 22, and the like are controlled. FIG. 4 is a functional block diagram of the control circuit 11. Functionally, the control circuit 11 includes a pitch angle detection unit 11a, a determination processing unit 11b, and an engine control unit 11c.

  The pitch angle detection unit 11a detects the acceleration component in the vertical direction of the vehicle (hereinafter referred to as the vertical component) and the acceleration component in the horizontal direction (hereinafter referred to as the horizontal component) at a predetermined sampling period. Then, using these acceleration components, the ratio between the projection component of the gravitational acceleration in the plane perpendicular to the front-rear direction of the vehicle and the gravitational acceleration is calculated as the pitch angle corresponding value. The calculation process of the pitch angle corresponding value is executed as follows, for example.

  First, the pitch angle detection unit 11a, based on the vertical component Adown and the horizontal component Alr, is an orthogonal projection component of gravity acceleration (hereinafter referred to as a vertical plane projection component) Avert with respect to a plane perpendicular to the longitudinal direction of the vehicle. Is calculated. Specifically, the square value of the vertical projection component Avert is calculated by adding the square value of the horizontal component Alr to the square value of the vertical component Adown (Avert ^ 2 = Adown ^ 2 + Alr ^ 2).

  Next, the pitch angle detection unit 11a calculates the cosine value cos (φ) of the vehicle pitch angle φ as a pitch angle corresponding value based on the gravitational acceleration G and the calculated vertical plane projection component Avert. Specifically, the pitch angle detection unit 11a divides the vertical plane projection component Avert by the gravitational acceleration G to calculate a cosine value cos (φ) of the pitch angle φ (cos (φ) = Avert / G). .

  FIG. 5 is a diagram for explaining processing for calculating the cosine value cos (φ) of the pitch angle φ. FIG. 5A is a conceptual diagram showing a state in which the vehicle M arranged in a posture inclined in the left-right direction is viewed from the front. FIG.5 (b) is a conceptual diagram which shows a mode that the same vehicle M as Fig.5 (a) is seen from a side. In FIG. 5A, D1 indicates the left-right direction of the vehicle M, and D2 indicates the vertical direction of the vehicle M. 5B, D indicates the front-rear direction of the vehicle M, and the vehicle M is inclined with respect to the road surface E by an angle φ.

  As shown in FIG. 5A, the vector of the vertical plane projection component Avert is decomposed into a vertical vector component Adown vector and a horizontal component Alr vector of the vehicle. Therefore, in this example, the pitch angle detection unit 11a substitutes the vertical component Adown and the horizontal component Alr detected by the acceleration sensor 13 into the above-described formula (Avert ^ 2 = Adown ^ 2 + Alr ^ 2). To calculate the vertical plane projection component Avert.

Further, as shown in FIG. 5B, the vertical plane projection component Avert and the gravitational acceleration G are in the relationship of the expression (1), and when the longitudinal axis of the vehicle tilts, the vertical projection component Avert It becomes smaller according to the angle φ. Therefore, in this example, the pitch angle detector 11a calculates the cosine value cos (φ) of the pitch angle φ by dividing the vertical plane projection component Avert by the gravitational acceleration G.
Avert = Gcos (φ) (1)

Note that the cosine value cos (φ) calculation processing by the pitch angle detection unit 11a is not limited to the method described above. For example, the vertical component Adown and the horizontal component Alr are substituted into the equation (2), the vertical projection component Avert is divided by the gravitational acceleration G, and the cosine value cos (φ) of the pitch angle is calculated. May be. In Equation (2), (√ (Adown ^ 2 + Alr ^ 2)) is a vertical projection component.
cos (φ) = √ (Adown ^ 2 + Alr ^ 2) / G (2)

  In addition, a table indicating the correspondence between the acceleration component and the pitch angle φ may be stored in the storage device 12 in advance. Then, the pitch angle detection unit 11a may calculate the cosine value cos (φ) of the pitch angle φ with reference to the table.

  For example, a table indicating the correspondence between the vertical plane projection component Avert and the cosine value cos (φ) of the pitch angle φ is stored in the storage device 12 in advance. Then, the pitch angle detection unit 11a calculates the vertical plane projection component Avert based on the vertical component Adown and the horizontal component Alr, and then refers to the table to cosine value cos corresponding to the vertical plane projection component Avert. (Φ) may be acquired.

  Further, a table indicating the correspondence between the pitch angle φ and the cosine value cos (φ) may be stored in the storage device 12 in advance. Then, the pitch angle detection unit 11a refers to the table, calculates the pitch angle φ from the cosine value cos (φ), and uses the pitch angle φ as a pitch angle corresponding value for the processing of the determination processing unit 11b described later. May be provided.

  Based on the pitch angle corresponding value calculated by the pitch angle detection unit 11a, the determination processing unit 11b determines whether or not the driving state of the vehicle corresponds to a start condition for processing by the engine control unit 11c described later. Here, the start condition is, for example, that the calculated pitch angle correspondence value falls below a predetermined threshold value (hereinafter, determination condition value). In this case, when the cosine value cos (φ) of the pitch angle φ is lower than the determination condition value, the determination processing unit 11b determines that the driving state of the vehicle corresponds to the processing start condition by the engine control unit 11c.

  Further, the determination processing unit 11b determines that the driving state corresponds to the start condition when the state where the cosine value cos (φ) of the pitch angle φ is lower than the determination condition value continues for a predetermined time or more. Also good.

  Further, the determination processing unit 11b may determine whether or not the start condition is satisfied based on not only the cosine value of the pitch angle but also other operating states. For example, a crank angle sensor for detecting the engine speed is installed in the engine 26a, and a throttle position sensor for detecting the throttle opening is installed in the throttle body 23. The determination processing unit 11b determines whether or not the driving state satisfies a predetermined condition based on a signal input from the crank angle sensor and a signal input from the throttle position sensor. The determination processing unit 11b determines that the start condition is satisfied when the driving state corresponds to the predetermined condition and the roll angle corresponding value (here, cosine value of the pitch angle) is smaller than the determination condition value. It may be determined that

  Here, the predetermined condition for the operating state is, for example, that the throttle opening is larger than a predetermined threshold and the engine speed is lower than a predetermined threshold. Thus, by setting the conditions, the determination processing unit 11b can detect that the vehicle is traveling on a steep slope, for example.

  When it is determined by the determination processing unit 11b that the start condition is satisfied, the engine control unit 11c performs engine control different from that during normal traveling.

  For example, when the determination processing unit 11b determines that the vehicle is traveling in wheelie based on the pitch angle corresponding value, the engine control unit 11c delays the ignition timing by the spark plug 21 from the timing during normal traveling. The output of the engine 26a is reduced by performing the retard control or reducing the fuel injection amount by the injector 22.

  When the determination processing unit 11b determines that the vehicle is traveling on a steep slope based on the pitch angle corresponding value, the engine speed, the throttle opening, and the like, the engine control unit 11c uses the injector 22 The output of the engine 26a may be increased by increasing the fuel injection amount.

  Here, the flow of processing executed by the control circuit 11 will be described. FIG. 6 is a flowchart illustrating an example of processing of the control circuit 11. Here, the description will be made assuming that the control by the engine control unit 11c is executed when the vehicle travels in a wheelie. Further, in the determination process for determining whether or not the vehicle is traveling in a wheelie, a case where it is determined that the vehicle is in a wheelie when the state in which the vehicle is tilted continues for a predetermined time or longer will be described as an example.

  The pitch angle detection unit 11a acquires an acceleration signal and detects the vertical component Adown and the horizontal component Alr (S101). Next, the pitch angle detector 11a calculates the cosine value cos (φ) of the pitch angle φ by substituting the vertical component Adown and the horizontal component Alr into the above-described equation (2) (S102). . Then, the determination processing unit 11b determines whether or not the cosine value cos (φ) is smaller than a predetermined threshold value cos φ1 (S103). Here, the threshold value cos φ1 is, for example, a value that is equal to or smaller than the determination condition value described above.

  If the cosine value cos (φ) of the pitch angle φ is equal to or greater than the threshold value cos φ1 in the determination of S103, the control circuit 11 returns to the processing of S101. On the other hand, if it is determined in S103 that the cosine value cos (φ) of the pitch angle is smaller than the threshold value cosφ1, there is a possibility that the vehicle is in wheelie travel. Therefore, the control circuit 11 indicates that the vehicle is leaning. A process of determining whether or not to continue for a predetermined time or longer is started.

  Specifically, the determination processing unit 11b first substitutes the initial value 1 for the parameter n (S104). Next, the pitch angle detector 11a detects the vertical component Adown and the horizontal component Alr (S105), and calculates the cosine value cos (φ) of the pitch angle φ based on the acceleration components (S106). ). Next, the determination processing unit 11b determines whether or not the cosine value cos (φ) is smaller than the determination condition value cosφ2 (S107). Here, when the cosine value cos (φ) is equal to or larger than the determination condition value cosφ2, the determination processing unit 11b determines that the vehicle is not traveling in a wheelie, and the process returns to S101.

  On the other hand, if the cosine value cos (φ) is smaller than the determination condition value cosφ2 in the determination in S107, the parameter n is incremented by 1 (S108), and whether or not the obtained parameter n is equal to or greater than a predetermined threshold value Nlim. Is determined (S109). Here, when the parameter n has not yet reached the predetermined threshold value Nlim, the process returns to S105, and the pitch angle detection unit 11a detects the horizontal component Alr and the vertical component Adown again.

  On the other hand, if the parameter n is greater than or equal to the threshold value Nlim in the determination of S109, the determination processing unit 11b determines that the vehicle is tilted for a predetermined time or longer and the vehicle is traveling in a wheelie. In this case, the engine control unit 11c reduces the output of the engine 26a by performing a retard control that delays the ignition timing by the spark plug 21 from the timing at the time of normal traveling, or by reducing the fuel injection amount by the injector 22. Output reduction control is started (S110).

  Thereafter, the control circuit 11 performs a process of determining whether or not the vehicle has ended the wheelie travel and has returned to the normal travel. When determining that the vehicle has returned to the normal travel, the control circuit 11 ends the output reduction control of the engine 26a.

  Specifically, the pitch angle detector 11a detects the vertical component Adown and the horizontal component Alr (S111), and calculates the cosine value cos (φ) of the pitch angle φ based on these acceleration components ( S112). Then, the determination processing unit 11b determines whether or not the cosine value cos (φ) is larger than a predetermined threshold value cos φ3 (S113). Here, when the cosine value cos (φ) of the pitch angle is equal to or smaller than the threshold value cosφ3, it is determined that the vehicle is still traveling in the wheelie, and the control circuit 11 returns to the processing of S111. On the other hand, if the cosine value cos (φ) of the pitch angle φ is larger than the threshold value cos φ3, it is determined that the vehicle has returned to normal running, and the engine control unit 11c ends the output reduction control and the ignition timing of the engine 26a. Alternatively, the output of the engine 26a is increased by increasing the amount of fuel injected by the injector 22 (S114). The above is an example of processing executed by the control circuit 11.

  According to the present invention, in detecting the pitch angle of the vehicle, for example, in addition to the sensor for detecting the vertical acceleration and the horizontal acceleration provided for detecting the roll angle of the vehicle, a new front-rear direction is provided. The pitch angle of the vehicle can be detected without a sensor for detecting the acceleration of the vehicle.

  Note that the present invention is not limited to the attitude detection device 10 described above, and various modifications can be made. For example, in the above description, the attitude detection device 10 includes the noise removal circuit 15 configured by an analog circuit. However, the posture detection device 10 may remove the noise signal from the signal output from the acceleration sensor 13 by digital processing. In this case, the output signal of the acceleration sensor 13 is converted into a digital signal by the A / D conversion circuit 14 and then input to a noise removal circuit including a CPU and the like. The output signal of the acceleration sensor 13 is subjected to high-pass filter processing and subtraction processing in the noise removal circuit, and the noise signal is removed and input to the control circuit 11 as an acceleration signal. Note that the control circuit 11 may include a noise removal circuit and execute high-pass filter processing or subtraction processing.

  In the above description, the acceleration sensor 13 is set so that the detection direction is the vertical direction and the horizontal direction of the vehicle. However, the detection direction of the acceleration sensor is not limited to this.

FIG. 7 is a diagram illustrating another example of the detection direction of the acceleration sensor 13. FIG. 7 is a conceptual diagram showing a state in which a vehicle inclined in the left-right direction is viewed from the front. Also in FIG. 7, D1 shows the left-right direction of the vehicle, and D2 shows the up-down direction of the vehicle. D1 ′ and D2 ′ indicate detection directions of the acceleration sensor 13. As shown in this figure, the detection directions D1 ′ and D2 ′ of the acceleration sensor 13 may be inclined by a predetermined angle α with respect to the left-right direction D1 and the up-down direction D2 of the vehicle, for example. In this case, the pitch angle detection unit 11a calculates the vertical component Adown and the horizontal component Alr based on the acceleration component Alr ′ in the D1 ′ direction and the acceleration component Adown ′ in the D2 ′ direction. For example, the pitch angle detection unit 11a substitutes the acceleration component Adown ′ and the acceleration component Alr ′ into the equations (3) and (4) for linear conversion, thereby obtaining the vertical component Adown and the horizontal component Alr. calculate. Then, the cosine value of the roll angle may be calculated based on the calculated vertical component Adown and horizontal component Alr. As a result, the degree of freedom in the layout of the acceleration sensor can be increased.
Alr = Alr ′ × cos (α) −Adown ′ × sin (α) (3)
Adown = Alr ′ × sin (α) + Adown ′ × cos (α) (4)

1 is a side view of a motorcycle equipped with an attitude detection device and an engine control device according to an embodiment of the present invention. It is a block diagram which shows the structure of the said engine control apparatus and the said attitude | position detection apparatus. It is a figure which shows the example of the output signal of the acceleration sensor with which the said attitude | position detection apparatus is provided, the output signal of a phase compensation circuit, and the output signal of a subtraction circuit. It is a functional block diagram of the control circuit with which the said attitude | position detection apparatus is provided. It is a figure for demonstrating the example of the calculation process which calculates the cosine value of a pitch angle. It is a flowchart which shows the example of the process which a control circuit performs. It is a figure which shows the other example of the detection direction of an acceleration sensor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Motorcycle, 3 Body frame, 6 Seat, 9 Pivot shaft, 10 Attitude detection apparatus, 11 Control circuit, 11a Pitch angle detection part (pitch angle detection means), 11b Judgment processing part, 11c Engine control part, 12 Storage device, 13 acceleration sensor, 14 A / D conversion circuit, 15 noise removal circuit, 15a high-pass filter circuit (noise extraction means), 15b phase compensation circuit, 15c subtraction circuit (subtraction means), 16 acceleration detection device (acceleration detection means), 20 Engine control device, 21 Spark plug, 22 Injector, 23 Air cleaner, 24 Intake pipe, 25 Throttle body, 26 Engine unit, Alr Vehicle left and right acceleration component (first direction acceleration component), Adown Vehicle up and down direction Acceleration component (acceleration component in the second direction), Avert vertical plane Shadow component (projection component of gravity acceleration with respect to plane perpendicular to vehicle longitudinal direction), D vehicle longitudinal direction, D1 vehicle lateral direction, D2 vehicle vertical direction, E road surface, G gravity acceleration, φ vehicle pitch angle.

Claims (8)

An acceleration component of gravitational acceleration in a first direction defined in a direction different from the front-rear direction of the vehicle;
Acceleration detecting means for detecting an acceleration component of gravity acceleration in a second direction defined in a direction different from the front-rear direction and the first direction;
Pitch angle detecting means for calculating a value corresponding to the pitch angle of the vehicle,
The pitch angle detecting means uses the acceleration component in the first direction and the acceleration component in the second direction to calculate a projection component of gravity acceleration in a plane perpendicular to the front-rear direction of the vehicle and the gravitational acceleration. Calculate the percentage as a value corresponding to the pitch angle,
Controlling the engine based on a value corresponding to the pitch angle;
A straddle-type vehicle characterized by that. First means for detecting an acceleration component of gravitational acceleration in a first direction determined in a direction different from the vehicle front-rear direction, and a second direction determined in a direction different from the front-rear direction and the first direction Acceleration detecting means including second means for detecting an acceleration component of gravitational acceleration in the direction of
Pitch angle detecting means for calculating a value corresponding to the pitch angle of the vehicle,
The pitch angle detecting means acquires the acceleration component in the vertical direction of the vehicle and the acceleration component in the horizontal direction of the vehicle using the first means and the second means, and squares the acceleration component in the vertical direction. The value corresponding to the pitch angle is calculated from the acquired acceleration component by using an arithmetic expression that obtains the ratio of the square root of the sum of the square of the acceleration component and the square of the acceleration component in the horizontal direction and the gravitational acceleration as a value corresponding to the pitch angle. To
A straddle-type vehicle characterized by that. The saddle riding type vehicle according to claim 1 or 2,
The first direction and the second direction are orthogonal to each other,
A straddle-type vehicle characterized by that. The saddle riding type vehicle according to claim 3,
The first direction is a left-right direction of the vehicle.
A straddle-type vehicle characterized by that. The saddle riding type vehicle according to claim 3,
The second direction is a vertical direction of the vehicle.
A straddle-type vehicle characterized by that. The saddle riding type vehicle according to claim 1 or 2,
The acceleration detection means includes a noise extraction means for extracting a noise signal from the detection signal, and a signal obtained by subtracting the noise signal extracted by the noise extraction means from the detection signal as a signal corresponding to the acceleration component. Subtracting means for outputting,
A straddle-type vehicle characterized by that. The saddle riding type vehicle according to claim 6,
The noise extraction means is a high pass filter circuit.
A straddle-type vehicle characterized by that. The saddle riding type vehicle according to claim 2,
A straddle-type vehicle that controls an engine based on the value corresponding to the pitch angle of the vehicle.

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