JP2008019742A - Atmospheric pressure estimating device, vehicle and atmospheric pressure estimating program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an atmospheric pressure estimating device capable of providing an accurate atmospheric pressure estimating value, without using an atmospheric pressure sensor for detecting atmospheric pressure. <P>SOLUTION: Reference intake pipe pressure (p) corresponding to actual throttle opening and an actual engine speed detected in an atmospheric pressure estimating period, is acquired by referring to corresponding relationship data on the corresponding relationship between throttle opening, an engine speed and intake pipe pressure measured in advance under predetermined reference atmospheric pressure. The predetermined reference atmospheric pressure is set to P. Actual intake pipe pressure detected in the atmospheric pressure estimating period is set to Pa. The atmospheric pressure estimating value is calculated on the basis of actual atmospheric pressure, by calculating the actual atmospheric pressure by an expression Pa = pa ×(P/p), by using the reference intake pipe pressure (p), the reference atmospheric pressure P and the actual intake pipe pressure Pa. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an atmospheric pressure estimation device that estimates atmospheric pressure, a vehicle including the atmospheric pressure estimation device, and an atmospheric pressure estimation program.

  In a vehicle such as a motorcycle, it is necessary to accurately acquire the atmospheric pressure in order to accurately adjust the pressure of fuel supplied to the fuel injection device. Here, it is conceivable to mount an atmospheric pressure sensor that directly detects the atmospheric pressure. However, since the atmospheric pressure sensor is large and expensive, it is particularly difficult to mount it on a motorcycle. Therefore, the appearance of an atmospheric pressure estimation device capable of accurately estimating the atmospheric pressure from the operating state of the engine or the like is desired.

Conventionally, for example, an atmospheric pressure estimation device described in Patent Document 1 is known. In this atmospheric pressure estimation device, the relationship between the engine speed at the reference atmospheric pressure, the throttle opening, and the intake pipe pressure (pressure in the engine intake pipe) is actually measured and stored in advance as a table. In the atmospheric pressure estimation device, the intake pipe pressure under the reference atmospheric pressure (reference intake pipe pressure) is obtained based on the actually detected actual engine speed and actual throttle opening and the table. Based on the difference between the reference intake pipe pressure and the actually detected actual intake pipe pressure, an estimated atmospheric pressure value is calculated.
Japanese Patent Publication No. 07-51912

  However, in the atmospheric pressure estimation device according to the above-described prior art, the estimated atmospheric pressure may deviate greatly from the actual atmospheric pressure.

  The present invention has been made in view of this point, and provides an atmospheric pressure estimation device capable of obtaining an accurate atmospheric pressure estimation value, a vehicle including the atmospheric pressure estimation device, and an atmospheric pressure estimation program. The purpose is to do.

  An atmospheric pressure estimation device according to the present invention includes an engine having an intake pipe, a throttle valve that adjusts an intake air amount of the engine, a throttle opening detection device that detects a throttle opening that is an opening of the throttle valve, It is mounted on a vehicle equipped with an engine speed detecting device that detects an engine speed that is the engine speed and an intake pipe pressure detecting device that detects an intake pipe pressure that is a pressure inside the intake pipe. An atmospheric pressure estimation device for estimating, a storage device for storing correspondence data relating to a correspondence relationship between a throttle opening, an engine speed, and an intake pipe pressure measured in advance under a predetermined reference atmospheric pressure; The actual throttle opening detected by the throttle opening detection device from the correspondence data stored in the storage device, and the engine speed detection device Acquisition means for acquiring a reference intake pipe pressure that is an intake pipe pressure under the reference atmospheric pressure corresponding to the actual engine speed detected from the reference, and the reference intake pipe pressure acquired by the acquisition means and the reference atmospheric pressure The actual atmospheric pressure calculating means for calculating the actual atmospheric pressure, which is the current atmospheric pressure, based on the ratio to the actual intake pipe pressure detected by the intake pipe pressure detecting device, and the actual atmospheric pressure calculating means And an estimated value calculating means for calculating the estimated atmospheric pressure based on the actual atmospheric pressure calculated by the above.

  According to the atmospheric pressure estimation device, based on the ratio of the reference intake pipe pressure acquired by the acquisition means and the reference atmospheric pressure, and the actual intake pipe pressure detected by the intake pipe pressure detection device, An estimated atmospheric pressure value is calculated. Therefore, it is possible to obtain an accurate estimated atmospheric pressure value.

  According to the present invention, it is possible to obtain an accurate estimated atmospheric pressure value without using an atmospheric pressure sensor that detects atmospheric pressure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
As shown in FIG. 1, the saddle riding type vehicle according to the present embodiment is a scooter type motorcycle 1. FIG. 1 is a side view of the motorcycle 1, and FIG. 2 is a sectional view taken along line II-II in FIG.

  The motorcycle 1 includes a handle 2 and a seat 3. Between the handle 2 and the seat 3, a low floor footrest plate 4 is provided. A vehicle body cover 5 that covers the lower portion of the seat 3 is provided at the rear portion of the seat 3.

  The motorcycle 1 includes a body frame 6 extending in the front-rear direction. The vehicle body frame 6 includes a front frame 6a composed of a single tube, a rear frame 6b composed of two tubes branched from the rear end of the front frame 6a to the left and right.

  The motorcycle 1 includes an engine unit 7. The engine unit 7 is disposed in the vehicle body cover 5 below the seat 3. The engine unit 7 includes a single-cylinder four-cycle engine 8, a power transmission mechanism including a V-belt 10 (see FIG. 2) that transmits the power of the engine 8 to the rear, and a rear wheel that houses the power transmission mechanism. 9 and a transmission case 11 that supports 9. The transmission case 11 is provided on the left side of the vehicle body as shown in FIG.

  In FIG. 1, reference numeral 12 denotes a bracket for pivotally supporting the engine unit 7 on the rear frame 6b. Reference numeral 13 denotes a shock absorber that absorbs the vertical movement of the rear portion of the transmission case 11, and is interposed between the rear end portion of the transmission case 11 and the rear frame 6b.

  The engine 8 includes a cylinder body 14 that is inclined rearward, a cylinder head 15, and an engine case 17 in which a crank case 16 and an inner portion of the transmission case 11 are integrally formed. A single cylinder hole 14 a is provided inside the cylinder body 14, and a cylinder sleeve 22 that holds the piston 21 is held therein. The cylinder sleeve 22 is fixed to the cylinder body 14 with an oval fixing plate 23 that presses the sleeve from below. A combustion chamber 24 is formed at the upper end of the cylinder hole 14a. The crankcase 16 is formed in a box shape having an opening opened downward. The crankshaft 27 is connected to the piston 21 via a connecting rod 26 and is supported by both side walls of the crankcase 16 so as to be rotatable in the vehicle width direction. Reference numeral 29 is a spark plug.

  FIG. 3 schematically shows a peripheral structure of a cylinder 81 in the engine 8 (the cylinder 81 is constituted by the cylinder body 14 and the cylinder head 15 described above), a fuel system of the engine 8, and a configuration of a control system. FIG. In the cylinder 81 of the engine 8, the piston 21 is accommodated so that reciprocation is possible. A combustion chamber 24 is formed by the upper surface of the piston 21 and the inner wall surface of the cylinder 81.

  An intake pipe 85 and an exhaust pipe 86 are connected to the cylinder 81. The intake pipe 85 communicates with the combustion chamber 24 via the intake port 87. An intake valve 88 that changes the communication state between the intake pipe 85 and the combustion chamber 24 by being opened and closed is disposed in the intake port 87. The intake pipe 85 is provided with an injector 89 that supplies fuel into the intake port 87.

  A throttle valve 46 is attached to the intake pipe 85. A throttle drive actuator 49 is provided at the right end of the valve shaft of the throttle valve 46, and a throttle opening sensor 50 is provided at the left end.

  The motorcycle 1 also includes an engine speed sensor 53 (see FIG. 2) that detects the speed of the engine 8.

  As shown in FIG. 3, an intake pipe pressure sensor 90 for detecting the pressure in the intake pipe 85 (intake pipe pressure) is provided downstream of the throttle valve 46 in the intake pipe 85 (on the cylinder 81 side). Yes. The intake pipe pressure sensor 90 corresponds to the intake pipe pressure detection device according to the present invention. Note that the intake pipe pressure sensor 90 may be provided in the intake port 87 and detect the pressure in the intake port 87. The intake pipe pressure sensor 90 may be any sensor that detects the pressure between the throttle valve 46 and the intake valve 88 in the intake pipe 85 or the intake port 87.

  The exhaust pipe 86 is connected to the combustion chamber 24 via the exhaust port 97. The exhaust port 97 is provided with an exhaust valve 98 that changes the communication state between the exhaust pipe 86 and the combustion chamber 24 by being opened and closed.

  The engine 8 also includes a fuel system 120 that supplies fuel to the injector 89. The fuel system 120 includes a fuel tank 121, a fuel pump 122, and a fuel pipe 125. The fuel pump 122 is connected to the fuel tank 121. The fuel pump 122 pumps the fuel in the fuel tank 121 to the injector 89 through the fuel pipe 125.

  Fuel injection by the injector 89 is controlled by an ECU (engine control device) 100 connected to the injector 89. The ECU 100 is connected to a spark plug 29 and performs ignition control of the spark plug 29. Further, the ECU 100 performs drive control of the throttle drive actuator 49.

  The ECU 100 is connected to the intake pipe pressure sensor 90 described above as an input system. The ECU 100 is connected to a sensor group 130 as another input system. As shown in FIG. 4, the sensor group 130 includes an accelerator input sensor 42, a throttle opening sensor 50, an engine speed sensor 53, a main shaft speed sensor 56, a vehicle speed sensor 69, and a water temperature sensor 71. The water temperature sensor 71 detects the coolant temperature of the engine 8. This water temperature sensor 71 corresponds to the water temperature meter referred to in the present invention. The detection results of these sensors 42, 50, 53, 56, 69 and 71 are input to the ECU 100.

  As shown in FIG. 3, the ECU 100 includes a CPU 101, a RAM 102, a ROM 106, an input / output bus (not shown), and the like. The CPU 101 develops necessary programs and data stored in the ROM 106 in the RAM 102 and performs various processes. The ROM 106 corresponds to the storage device referred to in the present invention.

  FIG. 5 is a diagram illustrating programs and data stored in the ROM 106. The ROM 106 stores an engine control program 106a, an atmospheric pressure estimation program 106b, correspondence data 106c, and smoothing coefficient data 106d. The engine control program 106a is a program for performing drive control of the throttle drive actuator 49, the port injection injector 89, the spark plug 29 (see FIG. 3), and the like, and is a program for performing operation control of the entire engine 8. is there.

  The atmospheric pressure estimation program 106b is a program for acquiring an estimated value of atmospheric pressure based on various data including the intake pipe pressure detected by the intake pipe pressure sensor 90 (see FIG. 3). The atmospheric pressure estimation process based on the atmospheric pressure estimation program 106b will be described in detail later with reference to the drawings. The correspondence relationship data 106c and the smoothing coefficient data 106d are data to be referred to when performing atmospheric pressure estimation processing based on the atmospheric pressure estimation program 106b, as will be described in detail later.

  Next, an atmospheric pressure estimation process performed by the ECU 100 based on the above-described atmospheric pressure estimation program 106b will be described. The motorcycle 1 according to the embodiment does not include an atmospheric pressure sensor that directly detects the atmospheric pressure, and the intake pipe pressure detected by the intake pipe pressure sensor 90 and various types that constitute the sensor group 130 (see FIG. 4). Based on the detection result of the sensor, the atmospheric pressure is estimated.

  FIG. 6 is a diagram showing the time transition of the intake pipe pressure. As shown in the upper part of FIG. 6, the intake pipe pressure varies depending on each motion process (explosion process, exhaust process, intake process, and compression process) of the engine 8. In the intake process and the compression process, the fluctuation of the intake pipe pressure is relatively large, and in the explosion process and the exhaust process, the fluctuation of the intake pipe pressure is relatively small. In the present embodiment, the atmospheric pressure is estimated using the intake pipe pressure in a period including the exhaust process with the smallest fluctuation (hereinafter referred to as an atmospheric pressure estimation period).

  FIG. 7 is a flowchart showing a flow of atmospheric pressure estimation processing performed by the ECU 100. This atmospheric pressure estimation process is a process (interrupt process) performed in response to the crank pulse generated by the engine speed sensor 53 being supplied to the ECU 100.

  Here, as shown in FIG. 6, the engine speed sensor 53 generates a crank pulse each time the crankshaft 27 rotates by a predetermined angle (30 ° in the present embodiment). The crank pulse generated by the engine speed sensor 53 is supplied to the ECU 100. Therefore, the atmospheric pressure estimation process is performed every time the crank pulse is input to the ECU 100.

  When the atmospheric pressure estimation process is started, first, in step S100, it is determined whether or not the crank angle has become the atmospheric pressure estimation start angle. In the present embodiment, as shown in FIG. 6, the crank angle at the start of the atmospheric pressure estimation period is preset as the atmospheric pressure estimation start angle. Note that the crank angle at the end of the atmospheric pressure estimation period is set in advance as the atmospheric pressure estimation end angle.

  If it is determined in step S100 that the crank angle is the atmospheric pressure estimation start angle, then in step S110, the atmospheric pressure estimation execution flag is set to ON. The fact that the atmospheric pressure estimation flag is ON means that the current time is within the atmospheric pressure estimation period.

  On the other hand, if it is determined in step S100 that the crank angle is not the atmospheric pressure estimation start angle, it is then determined in step S120 whether or not the atmospheric pressure estimation execution flag is set to ON. That is, in the process of step S120, it is determined whether or not the current time is within the atmospheric pressure estimation period. If it is determined in step S120 that the atmospheric pressure estimation execution flag is not ON (is OFF), the atmospheric pressure estimation process is terminated. Therefore, the atmospheric pressure is not estimated at this time.

  When the process of step S110 is executed, or when it is determined in step S120 that the atmospheric pressure estimation execution flag is set to ON, the current time is within the atmospheric pressure estimation period. Next, in step S130, Update the intake pipe pressure buffer. The intake pipe pressure buffer is an integrated value of the intake pipe pressure (the intake pipe pressure detected by the intake pipe pressure sensor 90) from the start of the atmospheric pressure estimation period to the present time. In the process of step S130, the ECU 100 determines the intake pipe pressure buffer (intake pipe pressure buffer (old)) calculated by the previous process of step S130 and the current intake pipe pressure detected by the intake pipe pressure sensor 90. Is updated as the current intake pipe pressure buffer (intake pipe pressure buffer (new)).

  After the processing of step S130 is executed, next, the average calculation counter is updated in step S140. This average calculation counter is a numerical value used when calculating the average value of the intake pipe pressure during the atmospheric pressure estimation period in the process of step S160 described later. In other words, this average calculation counter is the number of times the intake pipe pressure buffer has been updated by the process of step S130 from the start of the atmospheric pressure estimation period to the present time. In the process of step S140, the ECU 100 adds the sum of 1 to the average calculation counter (average calculation counter (old)) calculated in the previous step S140, and calculates the current average calculation counter (average calculation counter). Update as counter (new).

  After the process of step S140 is executed, it is next determined in step S150 whether or not the crank angle has become the atmospheric pressure estimation end angle. As described above, in the present embodiment, the crank angle at the end of the atmospheric pressure estimation period is preset as the atmospheric pressure estimation end angle (see FIG. 6). If it is determined in step S150 that the crank angle is not the atmospheric pressure estimation end angle, the atmospheric pressure estimation process is temporarily terminated. In this case, when the crankshaft 27 is further rotated by 30 ° and the crank pulse is supplied to the ECU 100, the atmospheric pressure estimation process is started again. On the other hand, if it is determined in step S150 that the crank angle has reached the atmospheric pressure estimation end angle, the process proceeds to step S160.

  When the crank angle reaches the atmospheric pressure estimation end angle, the sum of the intake pipe pressures (intake pipe pressure buffer) during the atmospheric pressure estimation period is calculated by the process of step S130 performed each time a crank pulse is generated. At this time, the number of times the intake pipe pressure buffer is updated (average calculation counter) is calculated by the process of step S140 performed each time a crank pulse is generated.

  In the process of step S160, using these intake pipe pressure buffers and the average calculation counter, the average value of the intake pipe pressure detected every time the crank pulse is generated during the atmospheric pressure estimation period (hereinafter referred to as the actual intake pipe pressure). ) Is calculated. That is, in the process of step S160, the ECU 100 calculates the actual intake pipe pressure by dividing the intake pipe pressure buffer updated by the process of step S130 by the average calculation counter updated by step S140.

  After the process of step S160 is executed, next, in step S170, the intake pipe pressure buffer and the average calculation counter are set to 0, and the atmospheric pressure estimation execution flag is set to OFF. This process is necessary for calculating the actual intake pipe pressure during the next atmospheric pressure estimation period after the current atmospheric pressure estimation period ends.

  After the process of step S170 is executed, the throttle fluctuation range is calculated in step S180. The throttle fluctuation range includes the maximum value (maximum throttle opening) of the throttle valve 46 during the atmospheric pressure estimation period (maximum throttle opening) and the minimum value (minimum of the throttle opening during the atmospheric pressure estimation period. (Throttle opening). In step S180, the ECU 100 calculates the difference between the maximum throttle opening and the minimum throttle opening as the throttle fluctuation range. The setting of the maximum throttle opening and the minimum throttle opening will be described later with reference to the drawing (FIG. 8).

  After the process of step S180 is executed, next, in step S190, the maximum throttle opening and the minimum throttle opening are cleared. Specifically, the maximum throttle opening is set to a predetermined minimum value (for example, zero), and the minimum throttle opening is set to a predetermined maximum value.

  After the process of step S190 is executed, it is next determined in step S200 whether the throttle fluctuation range is equal to or smaller than a predetermined threshold value. Although details will be described later, in the method for calculating the estimated atmospheric pressure value according to the present embodiment, when the throttle fluctuation range is large (exceeding the threshold value), the estimated atmospheric pressure value is likely to deviate from the actual atmospheric pressure. Therefore, if it is determined in step S200 that the throttle fluctuation range is not less than or equal to the threshold value (exceeds the threshold value), the atmospheric pressure estimation value described later is not calculated, and the atmospheric pressure estimation process is terminated.

  On the other hand, if it is determined in step S200 that the throttle fluctuation range is equal to or smaller than the predetermined threshold value, the correspondence relationship data 106c is searched in step S210. FIG. 9 is a diagram illustrating an example of the correspondence data 106c. As shown in FIG. 5, the correspondence relationship data 106 c is stored in the ROM 106 of the ECU 100. As shown in FIG. 9, the correspondence data includes the engine speed (EG speed) measured in advance under the reference atmospheric pressure (101.3 (kPa) in the present embodiment), and the throttle opening (Th opening). Degree) and the intake pipe pressure (map data).

  In the process of step S210, the ECU 100 determines the correspondence data 106c based on the engine speed detected by the engine speed sensor 53 and the actual throttle opening calculated based on the detection result of the throttle opening sensor 50. To obtain the intake pipe pressure (reference intake pipe pressure) corresponding to the engine speed and the actual throttle opening. When executing the process of step S210, the ECU 100 functions as an acquisition unit referred to in the present invention. The actual throttle opening is an average value obtained by performing a predetermined smoothing process on the throttle opening detected every predetermined time by the throttle opening sensor 50 during the atmospheric pressure estimation period. It is. The method for calculating the actual throttle opening will be described later with reference to the drawing (FIG. 8).

  In the process of step S210, for example, when the engine speed is 2000 (rpm) and the actual throttle opening is 60 °, the reference intake pipe pressure is 100 (kPa). For example, when the engine speed is 8000 (rpm) and the actual throttle opening is 1 °, the reference intake pipe pressure is 40 (kPa).

  After the process of step S210 is executed, next, in step S220, the atmospheric pressure smoothing coefficient data 106d (see FIG. 5) is searched. The atmospheric pressure smoothing coefficient is a coefficient used when performing a smoothing process on the actual atmospheric pressure (current atmospheric pressure) in calculating the atmospheric pressure estimated value. The actual atmospheric pressure is calculated by the process of step S230 described later. The annealing process is performed by the process in step S240.

  FIG. 10 is a diagram illustrating an example of atmospheric pressure smoothing coefficient data 106d. As shown in FIG. 5, the atmospheric pressure smoothing coefficient data 106 d is stored in the ROM 106 of the ECU 100. As shown in FIG. 10, the atmospheric pressure smoothing coefficient data 106d is data (map data) indicating the correspondence between the actual throttle opening degree and the atmospheric pressure smoothing coefficient.

  In step S220, the ECU 100 refers to the atmospheric pressure smoothing coefficient data 106d, and acquires an atmospheric pressure smoothing coefficient corresponding to the actual throttle opening. For example, when the actual throttle opening is 1 °, the atmospheric pressure smoothing coefficient is 1. Further, for example, when the actual throttle opening is 60 °, the atmospheric pressure smoothing coefficient is 64.

If the process of step S220 is performed, the process which calculates real atmospheric pressure will be performed in step S230 next. In the process of step S230, the ECU 100 calculates the actual atmospheric pressure using the following equation (1). That is, when the reference intake pipe pressure acquired by the process of step S210 is p, the reference atmospheric pressure (see FIG. 9) is P, and the actual intake pipe pressure calculated by the process of step S160 is pa, the actual atmospheric pressure. Pa is calculated using the following formula (1). When executing the process of step S230, the ECU 100 functions as the actual atmospheric pressure calculating means according to the present invention.
Pa = pa × (P / p) (1)

  Hereinafter, the technical significance of using the above formula (1) in the calculation of the actual atmospheric pressure will be described. FIG. 11 is a diagram showing the time transition of the intake pipe pressure for each atmospheric pressure. In FIG. 11, the change of the intake pipe pressure according to the change of the crank angle is shown for each atmospheric pressure (six types of atmospheric pressure). In FIG. 11, the engine speed and the throttle opening are constant. As shown in FIG. 11, the graph lines indicating the characteristics of the intake pipe pressure at each atmospheric pressure have substantially the same shape. As the atmospheric pressure decreases by a certain number (0.1), the graph lines are shifted downward at substantially equal intervals.

  Here, when the vertical axis (intake pipe pressure) in FIG. 11 is replaced with a pressure ratio defined by intake pipe pressure / atmospheric pressure, a graph as shown in FIG. 12 is obtained. In FIG. 12, the graph lines relating to the six atmospheric pressures all overlap. From this, it can be said that the pressure ratio at the same crank angle is the same regardless of the value of the atmospheric pressure under the condition that the engine speed and the throttle opening are constant. The above equation (1) is an equation for calculating the actual atmospheric pressure using the fact that the pressure ratio described above is constant.

If the process of step S230 is executed, next, in step S240, the atmospheric pressure estimated value is calculated by performing the smoothing process on the actual atmospheric pressure calculated by the process of step S230. In this process, the ECU 100 calculates the actual atmospheric pressure calculated by the process of step S230, the atmospheric pressure estimated value calculated by the previous process of step S240 (hereinafter referred to as an atmospheric pressure estimated value (old)), and step S220. The current atmospheric pressure estimated value (hereinafter referred to as the atmospheric pressure estimated value (new)) is calculated (updated) by the following equation (2) using the atmospheric pressure smoothing coefficient set by the above process. When executing the process of step S240, the ECU 100 functions as an estimated value calculating means.
Atmospheric pressure estimated value (new) = Atmospheric pressure estimated value (old) + (Actual atmospheric pressure−Atmospheric pressure estimated value (old)) × Atmospheric pressure smoothing coefficient / 256 Expression (2)

  When the atmospheric pressure estimated value is calculated by the process of step S240, the atmospheric pressure estimating process is terminated.

  Hereinafter, the throttle opening related value setting process for setting the maximum throttle opening, the minimum throttle opening used in the process of step S180 of the flowchart shown in FIG. 7, and the actual throttle opening used in the process of step S210 will be described. This will be described with reference to FIG. In general, this processing is based on the throttle opening detected by the throttle opening sensor 50 during the atmospheric pressure estimation period, and the maximum throttle opening, the minimum throttle opening, and the actual throttle opening are calculated. It is a process to set. Further, this process is a process (interrupt process) performed every time a predetermined minute time (1 ms in the present embodiment) elapses.

  When the throttle opening related value setting process is started, first, in step S300, it is determined whether or not the atmospheric pressure estimation execution flag is set to ON. That is, in the process of step S300, it is determined whether or not the current time is within the atmospheric pressure estimation period.

  If it is determined in step S300 that the atmospheric pressure estimation execution flag is not set to ON (OFF), then in step S310, the actual throttle opening is detected at the current throttle opening (current throttle Opening degree), and then the throttle opening related value setting process is terminated.

  On the other hand, if it is determined in step S300 that the atmospheric pressure estimation execution flag is set to ON, then in step S320, is the current throttle opening larger than the previously set maximum throttle opening? Determine whether or not. If it is determined that it is larger, next, in step S330, the current throttle opening is set (updated) as the maximum throttle opening. That is, the maximum throttle opening set in step S330 is the maximum value of the throttle opening from the start of the atmospheric pressure estimation period to the present time.

  When the process of step S330 is executed, or when it is determined in step S320 that the current throttle opening is not larger than the previously set maximum throttle opening (below the maximum throttle opening), In step S340, it is determined whether or not the current throttle opening is smaller than the previously set minimum throttle opening. If it is determined that the throttle opening is small, the current throttle opening is set (updated) as the minimum throttle opening in step S350.

When the process of step S350 is executed, or when it is determined in step S340 that the current throttle opening is not smaller than the previously set minimum throttle opening (is greater than or equal to the minimum throttle opening), In step S360, the actual throttle opening is calculated by performing a smoothing process on the current throttle opening. In this process, the ECU 100 uses the current throttle opening and the actual throttle opening calculated in the previous step S360 (hereinafter, actual throttle opening (old)) to The actual throttle opening (hereinafter, actual throttle opening (new)) is calculated (updated).
Actual throttle opening (new) = actual throttle opening (old) + (current throttle opening-actual throttle opening (old)) × throttle smoothing coefficient / 256 Formula (3)
In the present embodiment, the throttle smoothing coefficient is set in advance as a constant value.

  When the actual throttle opening is calculated by the process of step S360, the throttle opening related value setting process is terminated.

  As described above, the motorcycle 1 according to this embodiment calculates the actual atmospheric pressure by the above equation (1) based on the ratio between the reference intake pipe pressure p and the reference atmospheric pressure P, and this actual atmospheric pressure. Is configured to calculate an estimated atmospheric pressure value. As described above, the pressure ratio at the same crank angle has a characteristic that it is the same value regardless of the value of the atmospheric pressure under the condition that the engine speed and the throttle opening are constant. That is, in this embodiment, the atmospheric pressure estimated value is calculated by a calculation method that matches this characteristic. Therefore, it is possible to obtain an accurate estimated atmospheric pressure value without using an atmospheric pressure sensor that directly detects the atmospheric pressure.

  In the motorcycle 1 according to the present embodiment, an air flow sensor that detects the amount of air flowing into the intake pipe 85 (see FIG. 3) is not required for estimating the atmospheric pressure. Therefore, manufacturing cost can be suppressed.

  As described above, in the atmospheric pressure estimation process in the present embodiment, the estimated atmospheric pressure is calculated using the intake pipe pressure in the atmospheric pressure estimation period including the exhaust process in which the fluctuation of the intake pipe pressure is small. Here, as shown in FIG. 12, the pressure ratio at the same crank angle has a characteristic that it is the same value regardless of the value of the atmospheric pressure. Therefore, as the atmospheric pressure estimation period, in addition to the period shown in FIG. 6, for example, even when a period including a part or all of the periods in the explosion process, the intake process, and the compression process is set, an accurate An atmospheric pressure estimate can be obtained.

  On the other hand, the atmospheric pressure estimation device according to the prior art does not estimate the atmospheric pressure based on the pressure ratio characteristic shown in FIG. Therefore, the atmospheric pressure cannot be accurately estimated depending on the crank angle when the intake pipe pressure is detected.

  As described above, in the present embodiment, an accurate estimated atmospheric pressure value is obtained even if a period including a part or all of the periods in the explosion process, the intake process, and the compression process is set as the atmospheric pressure estimation period. be able to. However, as in the present embodiment, the period including the exhaust process in which the fluctuation of the intake pipe pressure is small is set as the atmospheric pressure estimation period, and the atmospheric pressure estimated value is calculated using the average value (actual intake pipe pressure) of the intake pipe pressure in this period. By calculating, a more accurate atmospheric pressure estimated value can be obtained. In the present embodiment, a period including a part of the exhaust process is set as the atmospheric pressure estimation period, but the present invention is not limited to this, and a period including the entire exhaust process may be set.

  Further, in the motorcycle 1 according to the present embodiment, the atmospheric pressure estimated value is calculated by performing the annealing process using the above formula (2) on the calculated actual atmospheric pressure. Therefore, the time change of the atmospheric pressure estimated value can be moderated. Further, the buffer capacity can be reduced as compared with the process of calculating the average value.

  Further, in the motorcycle 1 according to the embodiment, as shown in FIG. 10, as the actual throttle opening approaches the fully closed state (0 °), the atmospheric pressure smoothing coefficient is set to a smaller value, and the actual throttle opening is reduced. The closer the degree is to the fully open state (80 °), the smaller the value is set. When the actual throttle opening is in the fully closed state or close to the fully open state, the pressure ratio characteristic shown in FIG. That is, in FIG. 12, there is a tendency that the graph lines of the pressure ratio at each atmospheric pressure do not match. Therefore, in the state where the actual throttle opening is in the fully closed state or close to the fully open state, by setting the atmospheric pressure smoothing coefficient to a small value, the contribution rate of the actual atmospheric pressure calculated in this state to the estimated atmospheric pressure value Can be lowered. As a result, a more accurate atmospheric pressure estimated value can be obtained.

  Further, in the motorcycle 1 according to the embodiment, when the throttle fluctuation range is equal to or smaller than the predetermined threshold value, the atmospheric pressure is estimated by the process of step S240 in FIG. If it exceeds, atmospheric pressure is not estimated. Here, as shown in FIG. 12, when the throttle opening is constant, the graph line of the pressure ratio matches at each atmospheric pressure. However, when the throttle opening greatly fluctuates, the characteristic that the above-described graph lines coincide with each other is destroyed. Therefore, if the throttle fluctuation range is large, an accurate estimated atmospheric pressure value cannot be obtained.

  However, in the present embodiment, the atmospheric pressure estimated value is calculated only when the throttle fluctuation range is small (when it is equal to or smaller than the threshold value). Therefore, it is possible to calculate an estimated atmospheric pressure value in a state where the characteristics that the graph lines in FIG. 12 match are maintained, and it is possible to obtain an accurate estimated atmospheric pressure value.

<Second Embodiment>
In the second embodiment described below, a case will be described in which a motorcycle includes an idle speed control valve 150 (hereinafter referred to as an ISC valve) driven by a step motor 151.

  FIG. 13 is a diagram showing a schematic configuration in the vicinity of the throttle valve 46 of the motorcycle according to the second embodiment. In the second embodiment, the configuration other than that shown in FIG. 13 is the same as that of the motorcycle 1 according to the first embodiment, and a description thereof will be omitted. Further, in FIG. 13, the same members and devices as those of the motorcycle 1 according to the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 13, a bypass circuit 85 a that bypasses the throttle valve 46 is formed in the intake pipe 85 (see also FIG. 3). Further, an ISC valve 150 that adjusts the amount of air that passes through the bypass circuit 85a and flows into the intake pipe main path 85b is provided at a portion of the intake pipe 85 where the bypass circuit 85a is formed. The ISC valve 150 is driven by a step motor 151. When the ISC valve 150 is driven by the step motor 151, the opening thereof continuously changes as shown by the white arrow in the figure.

  The drive control of the ISC valve 150 (specifically, the drive control of the step motor 151) is performed by the ECU 100 (see FIG. 3). That is, ECU 100 has a predetermined engine idling speed when the vehicle speed is 0 or substantially 0 and the throttle opening is fully closed (0 °) or substantially fully closed (idling state). The feedback control is performed to adjust the opening of the ISC valve 150 so that the number of the ISC valve 150 is open. Specifically, when the engine speed becomes higher than the idling speed, the ISC valve 150 is driven in the closing direction to reduce the inflow air amount. On the other hand, when the engine speed becomes lower than the idling speed, the ISC valve 150 is driven in the opening direction to increase the inflow air amount.

  FIG. 14 is a flowchart showing a flow of atmospheric pressure estimation processing performed by the ECU 100 of the motorcycle according to the second embodiment. In FIG. 14, the same steps as those in the flowchart of FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted.

  When the atmospheric pressure estimation process shown in FIG. 14 is started, first, in step S400, it is determined whether feedback control is being executed. In this process, the ECU 100 determines whether or not the drive control of the ISC valve 150 based on the input of the engine speed from the engine speed sensor 53 is being executed. In step S400, feedback control is performed by determining whether or not the vehicle is idling based on the throttle opening detected by the throttle opening sensor 50 and the vehicle speed detected by the vehicle speed sensor 69. It may be determined whether or not it is being executed. In this case, feedback control is being executed when the engine is idling.

  If it is determined in step S400 that the feedback control is not being executed, the process proceeds to step S100. If it is determined that the feedback control is being executed, the atmospheric pressure estimation process is terminated.

  As described above, in the motorcycle according to this embodiment, when the feedback control of the ISC valve 150 is being executed, the atmospheric pressure estimation process ends. That is, atmospheric pressure is not estimated during execution of feedback control. By the way, even if the throttle opening is constant, if the opening of the ISC valve 150 fluctuates, the amount of air flowing into the intake pipe 85 downstream of the throttle valve 46 fluctuates. . Therefore, even in this case, the characteristic that the graph lines shown in FIG.

  However, in this embodiment, when the feedback control of the ISC valve 150 is being executed, the atmospheric pressure estimated value is not calculated. Therefore, it is possible to calculate an estimated atmospheric pressure value in a state where the characteristics in FIG. 12 are maintained, and it is possible to obtain an accurate estimated atmospheric pressure value.

<Third Embodiment>
By the way, the ISC valve 150 described above is driven and controlled in accordance with the coolant temperature of the engine in addition to being driven and controlled when the engine speed is controlled in the idling state. Specifically, a larger opening is set when the water temperature is low, and a smaller opening is set when the water temperature is high. This is intended to keep the engine speed the same in any case, increasing the inflow air amount at low temperatures when the engine friction (loss horsepower) is large, and decreasing the inflow air amount at high temperatures with small friction. .

  FIG. 15 is a flowchart showing a flow of atmospheric pressure estimation processing performed by the ECU 100 of the motorcycle according to the third embodiment. In FIG. 15, the same steps as those in the flowchart of FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted. In addition, the configuration of the motorcycle according to the third embodiment is the same as that of the motorcycle 1 according to the first embodiment, and a description thereof will be omitted.

  When the atmospheric pressure estimation process shown in FIG. 15 is started, first, in step S500, it is determined whether or not the water temperature fluctuation rate exceeds a predetermined threshold value. In this process, the ECU 100 first calculates the water temperature fluctuation rate based on the detection result of the water temperature sensor 71 (see FIG. 4). Then, ECU 100 determines whether or not the water temperature fluctuation rate exceeds a predetermined threshold value.

  If it is determined in step S500 that the water temperature fluctuation rate does not exceed the threshold value (below the threshold value), the process proceeds to step S100. If it is determined that the threshold value exceeds the threshold value, the atmospheric pressure estimation process is terminated.

  As described above, in the motorcycle according to the present embodiment, when the water temperature fluctuation rate is large (exceeds a threshold value), the atmospheric pressure estimation process ends. As described above, the ISC valve 150 is driven in conjunction with a change in water temperature. Therefore, if the water temperature fluctuation rate is large, the fluctuation in the amount of air flowing into the intake pipe 85 downstream of the throttle valve 46 is large. Therefore, even in this case, the characteristic that the graph lines shown in FIG.

  However, in this embodiment, when the water temperature fluctuation rate is large, the atmospheric pressure estimated value is not calculated. Therefore, it is possible to calculate an estimated atmospheric pressure value in a state where the characteristics in FIG. 12 are maintained, and it is possible to obtain an accurate estimated atmospheric pressure value.

<Fourth embodiment>
In the fourth embodiment described below, a case will be described in which a motorcycle includes an ISC valve 250 driven by a duty solenoid 251.

  FIG. 16 is a diagram showing a schematic configuration in the vicinity of the throttle valve 46 of the motorcycle according to the fourth embodiment. In addition, in 4th Embodiment, since it is the same as that of the motorcycle 1 which concerns on 1st Embodiment about the structure other than having shown in FIG. 16, the description is abbreviate | omitted. Further, in FIG. 16, the same members and devices as those of the motorcycle 1 according to the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 16, the intake pipe 85 (see also FIG. 3) is formed with first and second bypass circuits 85c and 85d that bypass the throttle valve 46, respectively. In addition, an ISC valve 250 that controls the amount of air that passes through the bypass circuit 85c and flows into the intake pipe main path 85 is provided in a portion of the intake pipe 85 where the first bypass circuit 85c is formed. The ISC valve 250 is driven by a duty solenoid 251 and adjusts the amount of air flowing into the first detour 85c. The duty solenoid 251 determines the valve opening rate (time ratio during which the valve is open) of the ISC valve 250 based on the duty ratio of the driving voltage (ratio of energization time per unit time). For example, when the duty ratio is 0%, the valve opening rate is 0%, and when the duty ratio is 80%, the valve opening rate is also 80%.

  FIG. 17 is a flowchart showing a flow of atmospheric pressure estimation processing performed by the ECU 100 of the motorcycle according to the fourth embodiment. In FIG. 17, the same steps as those in the flowchart of FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted.

  When the atmospheric pressure estimation process shown in FIG. 17 is started, first, in step S600, it is determined whether or not the duty ratio is zero. In this process, the ECU 100 determines whether or not the duty ratio of the drive voltage of the duty solenoid 251 is zero. Note that the duty ratio of 0 means that the duty solenoid 251 is not driven. That is, the valve opening rate of the ISC valve 250 is zero.

  If it is determined in step S600 that the duty ratio is 0, the process proceeds to step S100. If it is determined that the duty ratio is not 0, the atmospheric pressure estimation process is terminated.

  As described above, in the motorcycle according to the present embodiment, when the duty ratio of the ISC valve 250 is not 0, the atmospheric pressure estimation process ends. That is, the atmospheric pressure is not estimated while the duty solenoid 251 is being driven. When the duty ratio is not 0, the ISC valve 250 is opened for a predetermined time, and accordingly, the amount of air flowing into the intake pipe 85 downstream of the throttle valve 46 varies. Therefore, even in this case, the characteristics shown in FIG.

  However, in the present embodiment, the atmospheric pressure estimated value is not calculated during the opening / closing operation of the ISC valve 250. Therefore, it is possible to calculate an estimated atmospheric pressure value in a state where the characteristics of FIG. 12 are maintained, and it is possible to obtain an accurate estimated atmospheric pressure value.

  In the second to fourth embodiments described above, when the amount of air flowing to the downstream side of the throttle valve 46 in the intake pipe 85 fluctuates, the estimation of the atmospheric pressure is stopped by terminating the atmospheric pressure estimation process. (See FIGS. 14, 15 and 17). However, as a method for canceling the estimation of the atmospheric pressure, a method described below can be adopted in addition to the method for ending the atmospheric pressure estimation process. That is, a method of setting the atmospheric pressure smoothing coefficient used when calculating the atmospheric pressure estimated value by the process of step S240 to substantially zero can be mentioned. Even when this method is used, the same effect as the method of ending the atmospheric pressure estimation process can be obtained. Note that “the atmospheric pressure smoothing coefficient is set to approximately 0” means that the atmospheric pressure smoothing coefficient is set to a small value that does not substantially contribute to the update of the atmospheric pressure estimated value in addition to the case where the atmospheric pressure smoothing coefficient is set to 0. It also means including setting. In the second to fourth embodiments, for example, when the atmospheric pressure smoothing coefficient is in the range of 0 to 5, it becomes substantially zero.

  In the embodiment (first to fourth embodiments), the actual intake pipe pressure is an average value of the intake pipe pressure detected a plurality of times by the intake pipe pressure sensor 90 during the atmospheric pressure estimation period. Explained. However, the actual intake pipe pressure is not limited to this average value. For example, a single detection result of the intake pipe pressure sensor 90 may be used. Further, it may be a value obtained by subjecting the detection result of the intake pipe pressure sensor 90 to a smoothing process.

  In the embodiment, the actual throttle opening is a value obtained by subjecting the throttle opening detected every predetermined minute time (1 ms) to a smoothing process during the atmospheric pressure estimation period. explained. However, the actual throttle opening is not limited to the value after the annealing process. For example, a single detection result of the throttle opening sensor 50 may be used. Further, it may be an average value of throttle openings detected a plurality of times by the throttle opening sensor 50 during a predetermined period.

  As described above, the present invention is useful for an atmospheric pressure estimation device.

1 is a side view of a motorcycle according to a first embodiment. It is a fragmentary sectional view of an engine unit. It is a figure which shows typically the structure of the surrounding structure of the cylinder in an engine, the fuel system of an engine, and a control system. It is a block diagram which shows a sensor group. It is a figure which shows the program and data memorize | stored in ROM. It is a figure which shows time transition of an intake pipe pressure. It is a flowchart which shows an atmospheric pressure estimation process. It is a flowchart which shows a throttle opening related value setting process. It is a figure which shows correspondence data. It is a figure which shows atmospheric pressure annealing coefficient data. It is a figure which shows the time transition of an intake pipe pressure for every atmospheric pressure. It is a figure which shows the time transition of a pressure ratio for every atmospheric pressure. It is a figure which shows schematic structure of the throttle valve vicinity of the motorcycle which concerns on 2nd Embodiment. It is a flowchart which shows the atmospheric pressure estimation process which concerns on 2nd Embodiment. It is a flowchart which shows the atmospheric pressure estimation process which concerns on 3rd Embodiment. FIG. 6 is a diagram showing a schematic configuration in the vicinity of a throttle valve of a motorcycle according to a fourth embodiment. It is a flowchart which shows the atmospheric pressure estimation process which concerns on 4th Embodiment.

Explanation of symbols

1 Motorcycle (vehicle)
8 Engine 46 Throttle valve 49 Throttle drive actuator 50 Throttle opening sensor (throttle opening detector)
53 Engine speed sensor (Engine speed detector)
69 Vehicle speed sensor 71 Water temperature sensor 85 Intake pipe 90 Intake pipe pressure sensor (Intake pipe pressure detection device)
100 ECU (atmospheric pressure estimation device, acquisition means, actual atmospheric pressure calculation means, estimated value calculation means)
101 CPU
102 RAM
106 ROM (storage device)
150, 250 ISC valve (idle speed control valve)
151 Step motor 251 Duty solenoid

Claims (18)

An engine having an intake pipe, a throttle valve that adjusts the intake air amount of the engine, a throttle opening degree detecting device that detects a throttle opening degree that is an opening degree of the throttle valve, and an engine speed that detects the rotational speed of the engine An atmospheric pressure estimation device that is mounted on a vehicle including a number detection device and an intake pipe pressure detection device that detects an intake pipe pressure that is a pressure in the intake pipe, and that estimates an atmospheric pressure,
A storage device for storing correspondence data regarding a correspondence relationship between a throttle opening, an engine speed, and an intake pipe pressure measured in advance under a predetermined reference atmospheric pressure;
From the correspondence data stored in the storage device, the actual throttle opening detected by the throttle opening detector and the actual engine speed detected by the engine speed detector An acquisition means for acquiring an intake pipe pressure under a reference atmospheric pressure;
Based on the ratio between the intake pipe pressure acquired by the acquisition means and the reference atmospheric pressure, and the actual intake pipe pressure detected by the intake pipe pressure detection device, the actual atmospheric pressure that is the current atmospheric pressure is calculated. An actual atmospheric pressure calculating means for calculating;
An atmospheric pressure estimation device comprising: estimated value calculation means for calculating the estimated atmospheric pressure value based on the actual atmospheric pressure calculated by the actual atmospheric pressure calculation means. The actual atmospheric pressure calculating means is based on the intake pipe pressure p acquired by the acquiring means, the reference atmospheric pressure P, and the actual intake pipe pressure pa detected by the intake pipe pressure detecting device, The atmospheric pressure estimation device according to claim 1, wherein the actual atmospheric pressure Pa is calculated by 1).
Pa = pa × (P / p) (1)   The atmospheric pressure estimation according to claim 1, wherein the estimated value calculating means calculates an atmospheric pressure estimated value by performing a predetermined smoothing process on the actual atmospheric pressure calculated by the actual atmospheric pressure calculating means. apparatus.   The estimated value calculating means is a value obtained by multiplying a difference between the actual atmospheric pressure calculated by the actual atmospheric pressure calculating means and the previous atmospheric pressure estimated value that has been calculated previously by a predetermined annealing coefficient. The atmospheric pressure estimation apparatus according to claim 3, wherein a value obtained by adding the previous atmospheric pressure estimated value is the current atmospheric pressure estimated value.   The atmospheric pressure estimation device according to claim 4, wherein the smoothing coefficient is set for each throttle opening.   The atmospheric pressure estimation device according to claim 5, wherein the smoothing coefficient is set to a smaller value as the throttle opening degree approaches a fully closed state, and set to a smaller value as the throttle opening degree approaches a fully opened state.   The actual intake pipe pressure used when the actual atmospheric pressure is calculated by the actual atmospheric pressure calculating means is an average value of the intake pipe pressure detected by the intake pipe pressure detecting device every predetermined minute time over a predetermined period. The atmospheric pressure estimation device according to claim 1.   The atmospheric pressure estimation device according to claim 7, wherein the predetermined period is a period including at least all or a part of the exhaust process of the engine.   The atmospheric pressure estimation device according to claim 7, wherein when the fluctuation range of the throttle opening during the predetermined period exceeds a predetermined threshold, the actual atmospheric pressure is not calculated by the actual atmospheric pressure calculating means. The vehicle includes an idle speed control valve driven by a step motor,
When the throttle opening is equal to or less than a predetermined value, feedback control of the opening of the idle speed control valve is performed so that the engine speed becomes a constant value,
The atmospheric pressure estimation device according to claim 1, wherein when the feedback control of the opening degree of the idle speed control valve is being performed, the atmospheric pressure estimation value is not acquired. The vehicle includes a thermometer that detects a coolant temperature.
The idle speed control valve is driven in conjunction with a change in water temperature,
The atmospheric pressure estimation device according to claim 10, wherein the atmospheric pressure estimation value is not acquired when a variation rate of the water temperature detected by the water temperature meter exceeds a predetermined value.   The atmospheric pressure estimation apparatus according to claim 10 or 11, wherein when the feedback control of the opening degree of the idle speed control valve is performed, the actual atmospheric pressure is not calculated by the actual atmospheric pressure calculating means. The vehicle includes an idle speed control valve driven by a step motor,
When the throttle opening is equal to or less than a predetermined value, feedback control of the opening of the idle speed control valve is performed so that the engine speed becomes a constant value,
The atmospheric pressure estimation device according to claim 5, wherein the smoothing coefficient is set to approximately 0 when the throttle opening is equal to or less than the predetermined value. The vehicle includes an idle speed control valve driven by a duty solenoid,
The atmospheric pressure estimation device according to claim 1, wherein the atmospheric pressure estimation value is not acquired during driving of the idle speed control valve.   A vehicle comprising the atmospheric pressure estimation device according to claim 1.   The vehicle according to claim 15, which is a saddle type vehicle.   The vehicle according to claim 16, wherein the vehicle is a motorcycle. An engine having an intake pipe, a throttle valve that adjusts the intake air amount of the engine, a throttle opening degree detecting device that detects a throttle opening degree that is an opening degree of the throttle valve, and an engine speed that is the rotational speed of the engine An atmospheric pressure estimation device that is mounted on a vehicle including an engine speed detection device that detects the pressure and an intake pipe pressure detection device that detects an intake pipe pressure that is a pressure in the intake pipe, and that estimates an atmospheric pressure,
A storage device for storing correspondence data relating to a correspondence relationship between a throttle opening measured in advance under a predetermined reference atmospheric pressure, an engine speed, and an intake pipe pressure;
From the correspondence data stored in the storage device, the actual throttle opening detected by the throttle opening detector and the actual engine speed detected by the engine speed detector An acquisition means for acquiring an intake pipe pressure under a reference atmospheric pressure;
Based on the ratio between the intake pipe pressure acquired by the acquisition means and the reference atmospheric pressure, and the actual intake pipe pressure detected by the intake pipe pressure detection device, the actual atmospheric pressure that is the current atmospheric pressure is calculated. Actual atmospheric pressure calculating means for calculating, and
Estimated value calculating means for calculating the estimated atmospheric pressure based on the actual atmospheric pressure calculated by the actual atmospheric pressure calculating means;
Atmospheric pressure estimation program to function as.

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