Saddle riding-type vehicle

Abstract

This saddle riding-type vehicle includes: an engine; an automatic transmission that changes an output of the engine at a predetermined gear ratio and outputs the changed output; a selection means that selects one shift schedule from a plurality of shift schedules defining the gear ratio according to a traveling state including the vehicle speed of the saddle riding-type vehicle; and a gear ratio control means that controls the gear ratio of the automatic transmission on the basis of the shift schedule selected by the selection means and the traveling state. The plurality of shift schedules include a first shift schedule selected when it is determined that the throttle opening of the engine is equal to or less than a threshold value, and the threshold value is a value changed according to the vehicle speed.

Description

Straddle-type vehicle

[0001] The present invention relates to a straddle-type vehicle.

[0002] Techniques for controlling the gear ratio of an automatic transmission in accordance with the traveling state of a vehicle have been proposed. Patent Document 1 discloses a technique for switching a shift schedule when traveling downhill at a vehicle speed equal to or lower than a predetermined value, triggered by the driver's intention to decelerate and the throttle opening being near full closure.

[0003] Japanese Unexamined Patent Publication No. Hei 7-071589

[0004] Generally, running resistance, represented by rolling resistance and air resistance acting on a vehicle, increases as the vehicle speed increases. Furthermore, engine braking becomes greater as the engine rotational speed increases when the throttle opening is fully closed. In addition to the above, gravitational acceleration due to road surface smoothness and downhill gradient, reduction in running resistance due to tailwind, etc., and even action in the acceleration direction may occur on the vehicle body. When throttle adjustment with a minute opening is performed to maintain the vehicle speed under such circumstances, if the shift schedule is switched simply based on whether the throttle opening is fully closed as in Patent Document 1, switching of the shift schedule that deviates from the actual traveling situation may occur.

[0005] An object of the present invention is to provide a technique that suppresses the occurrence of deviation between the actual traveling situation and the selected shift schedule in control for switching the shift schedule based on throttle opening.

[0006] According to the present invention, a saddle-type vehicle (1) is provided, comprising: an engine (21); an automatic transmission (22) that shifts the output of the engine (21) at a predetermined gear ratio; a selection means (131) that selects one shift schedule from a plurality of shift schedules (401-403) that define the gear ratio according to the driving conditions including the vehicle speed of the saddle-type vehicle (1); and a gear ratio control means (131) that controls the gear ratio of the automatic transmission based on the shift schedule selected by the selection means and the driving conditions; wherein the plurality of shift schedules (401-403) includes a first shift schedule (402) that is selected when it is determined that the throttle opening of the engine is below a threshold; and the threshold is a value that is changed according to the vehicle speed.

[0007] According to the present invention, in control that switches the shift schedule based on the throttle opening, it is possible to provide a technique that suppresses discrepancies between the actual driving conditions and the selected shift schedule.

[0008] A right-side view of a saddle-type vehicle according to one embodiment of the present invention. A front view of the saddle-type vehicle in Figure 1. A block diagram of the control device. A flowchart showing an example of processing performed by the transmission control unit. A diagram showing an example of a shift schedule. A diagram showing an example of a shift schedule. A flowchart showing an example of processing performed by the transmission control unit. A diagram showing an example of a table for setting the switching threshold. A diagram showing another example of a table for setting the switching threshold. A diagram showing an example of a shift schedule. A flowchart showing another example of processing performed by the transmission control unit. A flowchart showing another example of processing performed by the transmission control unit. A diagram showing an example of a shift schedule. A flowchart showing another example of processing performed by the transmission control unit. A graph showing the relationship between engine speed and engine output due to driving resistance and throttle opening.

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more features from the multiple features described in the embodiments may be combined arbitrarily. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0010] <First Embodiment> <Overview of Saddle-Type Vehicle> Figure 1 is a right-side view of a saddle-type vehicle 1 according to one embodiment of the present invention, and Figure 2 is a front view of the saddle-type vehicle 1. In the figures, arrow D1 indicates the front-rear direction of the vehicle 1, arrow D2 indicates the width direction (left-right direction) of the vehicle 1, and arrow D3 indicates the up-down direction. F indicates the front side, and B indicates the rear side. R indicates the right side when moving forward, and L indicates the left side when moving forward. U indicates the upper side, and D indicates the lower side.

[0011] The saddle-type vehicle 1 is a touring-type motorcycle suitable for long-distance travel, but the present invention is applicable to various types of saddle-type vehicles, including other types of motorcycles. Hereinafter, the saddle-type vehicle 1 may be referred to as vehicle 1.

[0012] Vehicle 1 is equipped with a power unit 2 between the front wheels FW and the rear wheels RW. In this embodiment, the power unit 2 includes a horizontally opposed six-cylinder engine 21 and an automatic transmission 22 that shifts the output of the engine 21 to produce the output. The driving force of the automatic transmission 22 is transmitted to the rear wheels RW via a drive shaft (not shown), causing the rear wheels RW to rotate. The automatic transmission 22 in this embodiment is a dual-clutch transmission (DCT) and has gear ratios from 1st to 6th forward gear. The automatic transmission 22 may be an automated manual transmission (AMT) or a torque converter type automatic transmission instead of a DCT, or it may be a continuously variable transmission such as a CVT.

[0013] The power unit 2 is supported by the vehicle frame 3. The vehicle frame 3 includes a pair of left and right main frames 31 extending in the X direction. Above the main frames 31 are the fuel tank 5 and the air cleaner box (not shown). In front of the fuel tank 5 is a meter panel MP that displays various information to the rider.

[0014] The front end of the main frame 31 is provided with a head pipe 32 that rotatably supports a steering shaft (not shown) that is rotated by the handle 8. The rear end of the main frame 31 is provided with a pair of left and right pivot plates 33. The lower ends of the pivot plates 33 and the front end of the main frame 31 are connected by a pair of left and right lower arms (not shown), and the power unit 2 is supported by the main frame 31 and the lower arms. The rear end of the main frame 31 is also provided with a pair of left and right seat rails (not shown) that extend to the rear, and the seat rails support the seat 4a on which the rider sits, the seat 4b on which a passenger sits, and the rear trunk 7b, etc.

[0015] The pivot plate 33 supports the front end of a rear swing arm (not shown) that extends in the front-rear direction, allowing it to swing freely. The rear swing arm is capable of swinging in the vertical direction, and the rear wheel RW is supported at its rear end. An exhaust muffler 6, which silences the exhaust from the engine 21, extends in the X direction from the lower side of the rear wheel RW. Left and right saddlebags 7a are provided on the upper side of the rear wheel RW.

[0016] The front end of the main frame 31 is configured with a front suspension mechanism 9 that supports the front wheel FW. The front suspension mechanism 9 includes an upper link 91, a lower link 92, a fork support 93, a cushion unit 94, and a pair of left and right front forks 95.

[0017] The upper link 91 and lower link 92 are each positioned at the front end of the main frame 31 with a vertical gap between them. The rear ends of the upper link 91 and lower link 92 are pivotably connected to the front end of the main frame 31. The front ends of the upper link 91 and lower link 92 are pivotably connected to the fork support 93. The upper link 91 and lower link 92 each extend in the front-rear direction and are positioned substantially parallel to each other.

[0018] The cushion unit 94 has a structure in which a shock absorber is inserted through a coil spring, and its upper end is pivotably supported by the main frame 31. The lower end of the cushion unit 94 is pivotably supported by the lower link 92.

[0019] The fork support 93 is cylindrical and tilted backward. The front end of the upper link 21 is rotatably connected to the upper front part of the fork support 93. The front end of the lower link 92 is rotatably connected to the lower rear part of the fork support 93.

[0020] A steering shaft 96 is rotatably supported on a fork support 93. The steering shaft 96 has a shaft portion (not shown) that passes through the fork support 93. A bridge (not shown) is provided at the lower end of the steering shaft 96, and a pair of left and right front forks 95 are supported on this bridge. The front wheel FW is rotatably supported on the front forks 95. The upper end of the steering shaft 96 is connected via a link 97 to a steering shaft (not shown) that is rotated by a handle 8. The steering shaft 96 rotates when the handle 8 is turned, and the front wheel FW is steered. The upper part of the front wheel FW is covered by a fender 10, which is supported by the front forks 95.

[0021] Vehicle 1 is equipped with a brake device 19F for braking the front wheel FW and a brake device 19R for braking the rear wheel RW, and the brake devices 19F and 19R are configured to be operable by the rider's operation of the brake lever 8a or brake pedal 18. The brake devices 19F and 19R are, for example, disc brakes.

[0022] A headlight unit 11 that illuminates the front of the vehicle 1 is positioned at the front of the vehicle 1. The headlight unit 11 in this embodiment is a two-lens type headlight unit that has a right-side light-emitting section 11R and a left-side light-emitting section 11L arranged symmetrically. However, a single-lens type, a triple-lens type headlight unit, or an asymmetrical two-lens type headlight unit can also be used.

[0023] The front of the vehicle 1 is covered by a front cover 12, and the front sides of the vehicle 1 are covered by a pair of left and right side covers 14. A screen 13 is positioned above the front cover 12. The screen 13 is a windbreak that reduces the wind pressure experienced by the rider while riding, and is made of, for example, a transparent resin material. A pair of left and right side mirror units 15 are positioned on the sides of the front cover 12. The side mirror units 15 support side mirrors (not shown) for the rider to see behind them.

[0024] The front cover 12 includes cowl members 121 to 123, which together constitute the front cowl. Cowl member 121 extends in the Y direction and forms the main body of the front cover 12, while cowl member 122 forms the upper part of cowl member 121. Cowl member 123 is positioned at a downward distance from cowl member 121.

[0025] An opening is formed between cowl member 121 and cowl member 123, and between the pair of left and right side covers 14, exposing the headlight unit 11. The upper edge of this opening is defined by cowl member 121, the lower edge by cowl member 123, and the left and right side edges are defined by the side covers 14.

[0026] A detection unit 301 is positioned behind the front cover 12. The detection unit 301 is an external sensor that detects the situation in front of the vehicle 1. Hereinafter, the detection unit 301 will also be referred to as the external sensor 301. In this embodiment, the external sensor 301 is a radar (for example, a millimeter-wave radar) and is capable of detecting a preceding vehicle traveling in front of the vehicle 1. Note that the external sensor 301 may be other types of sensors, such as a camera.

[0027] <Control Device> Figure 3 is a block diagram of the control device 100 of the vehicle 1, and only the necessary components are shown in relation to the explanation described later. The control device 100 is an electronic circuit that controls the saddle-type vehicle 1 in response to the detection results of each sensor in the sensor group 300 and the rider's instructions via the input unit 200. The control device 100 includes a driving control unit 110, an engine control unit 120, and a gear shift control unit 130.

[0028] The driving control unit 110 performs control related to driver assistance. Driver assistance includes, as an example, driving control that automatically accelerates and decelerates the saddle-type vehicle 1. More specifically, it includes automatic cruise control and adaptive cruise control (ACC). With automatic cruise control, the driving control unit 110 automatically accelerates and decelerates the saddle-type vehicle 1 so that its speed is maintained at the target speed set by the rider. With ACC, the driving control unit 110 automatically accelerates and decelerates the saddle-type vehicle 1 so that the distance between the saddle-type vehicle 1 and the preceding vehicle detected by the external sensor 301 remains constant. The distance can be set by the rider. If there is no preceding vehicle, the same control as with automatic cruise control is performed, and the saddle-type vehicle 1 is automatically accelerated and decelerated so that its speed is maintained at the target speed set by the rider.

[0029] The engine control unit 120 controls the drive of the engine 21. The transmission control unit 130 controls the automatic transmission 22.

[0030] Each control unit 110 to 130 includes processing units 111, 121, and 131, storage units 112, 122, and 132, and interfaces (I / F) 113, 123, and 133. The processing units 111, 121, and 131 are processors, such as CPUs. The storage units 112, 122, and 132 are storage devices such as semiconductor memory. The I / F 113, 123, and 133 include input / output interfaces with external devices or communication interfaces for communication between control units 110 to 130. The storage units 112, 122, and 132 store programs executed by the processing units 111, 121, and 131, as well as data used by the processing units 111, 121, and 131 for processing.

[0031] The sensor group 300 includes an external sensor 301, a vehicle speed sensor 302, an inertia sensor 303, a throttle opening sensor 304, and a shift position sensor 305. The vehicle speed sensor 302 detects the vehicle speed of the vehicle 1. The vehicle speed sensor 302 is a sensor that detects the amount of rotation of, for example, the front wheel FW and the rear wheel RW. The inertia sensor 303 is a sensor that detects the behavior of the vehicle 1 and includes acceleration sensors that detect the acceleration of the vehicle 1 in the longitudinal, lateral, and vertical directions, and angular velocity sensors that detect the angular velocity of the vehicle 1 in the roll, pitch, and yaw directions. The throttle opening sensor 304 detects the throttle opening of the engine 21. The shift position sensor 305 detects the selected shift position. The input unit 200 is a switch or touch panel that can be operated by the rider, and the rider can perform actions such as ACC execution and setting the target vehicle speed via the input unit 200.

[0032] <Example of Gear Shift Control> An example of control of the automatic transmission 22 by the gear shift control unit 130 will be described. Figure 4 shows an example of processing performed by the processing unit 131, and shows the control of changing the gear ratio of the automatic transmission 22 in which a program stored in the memory unit 133 is periodically executed by the processing unit 131. In step S1, driving state information is acquired. Driving state information may include detection results from the sensor group 300 and control information inside the saddle-type vehicle 1. This information can also be distinguished into internal information of the saddle-type vehicle 1 and external information related to the driving environment. In step S1, driving state information necessary for gear shift control is acquired, and in this embodiment, at least vehicle speed information, throttle opening information, shift position information, and deceleration information are acquired.

[0033] Vehicle speed information is information used to identify the vehicle speed of vehicle 1. Vehicle speed information is, for example, the detection result of vehicle speed sensor 302. The detection result of vehicle speed sensor 302 may be received directly by the transmission control unit 130 from vehicle speed sensor 302, or it may be received via other control units 110 or 120. Throttle opening information is information used to identify the throttle opening of engine 21. Throttle opening information is, for example, the detection result of throttle opening sensor 304. The detection result of throttle opening sensor 304 may be received directly by the transmission control unit 130 from throttle opening sensor 304, or it may be received via other control units 110 or 120. Throttle opening information may also be a command value for the throttle opening output by engine control unit 120 to engine 21.

[0034] Shift position information is information used to identify the gear ratio (one of 1st to 6th gear) of the automatic transmission 22. Shift position information is, for example, the detection result of the shift position sensor 305. Deceleration information is information used to identify the deceleration of the vehicle 1. Deceleration information is, for example, the detection result of the inertia sensor 303, and in particular, the detection result of the acceleration sensor that detects the longitudinal acceleration of the vehicle 1.

[0035] In step S2, the shift schedule is acquired. The shift schedule is a map that defines the gear ratio according to the driving conditions and defines the timing of switching gear ratios. In this embodiment, multiple shift schedules are stored in the storage unit 132, and one shift schedule is selected by a selection process described later. In step S2, the data of the selected shift schedule is acquired.

[0036] Figure 5 shows an example of a shift schedule. Shift schedule 401 shows an example of a shift schedule that is normally selected. In the example shown, the horizontal axis is the vehicle speed V and the vertical axis is the throttle opening θ. Vehicle speeds V1 to V4 have the relationship V1 < V2 < V3 < V4. Vehicle speed V1 is, for example, a low vehicle speed in the range of 10 to 30 km / h, vehicle speeds V2 and V3 are, for example, intermediate vehicle speeds in the range of 20 to 70 km / h, and vehicle speed V4 is, for example, a high vehicle speed in the range of 70 to 90 km / h. A throttle opening of 0 means that the throttle is fully closed, and a large throttle opening means that the throttle is opened wider.

[0037] The shift-up lines SU1 to SU5 indicate the timing of shifting up. Shift-up line SU1 indicates the timing of switching from 1st to 2nd gear, shift-up line SU2 indicates the timing of switching from 2nd to 3rd gear, and shift-up line SU3 indicates the timing of switching from 3rd to 4th gear. Similarly, shift-up line SU4 indicates the timing of switching from 4th to 5th gear, and shift-up line SU5 indicates the timing of switching from 5th to 6th gear. When the position of the combination of vehicle speed V and throttle opening θ crosses a shift-up line, the gear ratio increases by one. For example, if the position of the combination of vehicle speed V and throttle opening θ changes to cross shift-up line SU3 as shown by arrow P1, the gear ratio will switch from 3rd to 4th gear.

[0038] The downshift lines SD1 to SD5 indicate the timing of downshifts. Downshift line SD1 indicates the timing of switching from 2nd gear to 1st gear, downshift line SD2 indicates the timing of switching from 3rd gear to 2nd gear, and downshift line SD3 indicates the timing of switching from 4th gear to 3rd gear. Similarly, downshift line SD4 indicates the timing of switching from 5th gear to 4th gear, and downshift line SD5 indicates the timing of switching from 6th gear to 5th gear. When the position of the combination of vehicle speed V and throttle opening θ crosses a downshift line, the gear ratio is reduced by one. For example, if the position of the combination of vehicle speed V and throttle opening θ changes to cross downshift line SD5 as shown by arrow P2, the gear ratio will be switched from 6th gear to 5th gear.

[0039] Shift schedule 402 in Figure 5 shows an alternative shift schedule. In this embodiment, shift schedule 402 can be selected when the throttle opening is below a switching threshold. Comparing shift schedules 401 and 402, at least a portion of the upshift lines SU1 to SU5 and downshift lines SD1 to SD5 are set to the higher vehicle speed side in shift schedule 402. More specifically, in shift schedule 402, the upshift lines SU1 to SU5 are generally set to the higher vehicle speed side. Under the same driving conditions, shift schedule 402 is set to be less likely to produce upshifts than shift schedule 401. Also, in shift schedule 402, the downshift lines SD1 to SD5 are generally set to be more likely to produce downshifts than shift schedule 401. Under the same driving conditions, shift schedule 402 is set to be more likely to produce downshifts than shift schedule 401.

[0040] The shift schedule 403 in Figure 6 shows yet another shift schedule. In this embodiment, shift schedule 403 is a downshift schedule that can be selected during deceleration. The horizontal axis is vehicle speed V, and the vertical axis is deceleration G. If the acceleration of the vehicle 1 in the forward direction is positive acceleration, then deceleration can be said to be negative acceleration. A deceleration of 0 means that the vehicle is traveling at a constant speed, and a large deceleration means that the absolute value of the negative acceleration is large.

[0041] In this embodiment, as an example, one shift schedule is selected from three types of shift schedules 401 to 403 to perform gear shift control. Note that there may be two types of shift schedules 401 to 403, or three or more types.

[0042] Returning to FIG. 4. In step S3, it is determined whether a shift change is necessary based on the driving state information acquired in step S1 and the shift schedule acquired in step S2. If it is determined to be unnecessary, the process ends; if it is determined to be necessary, the process proceeds to step S4. In step S4, shift change control for the automatic transmission 22 is performed. For example, when changing the gear ratio from an even gear to an odd gear, after the odd gear is set with the clutch on the odd gear side released, the clutch on the even gear side is released and the clutch on the odd gear side is engaged. The process ends as described above.

[0043] <Example of Shift Schedule Selection Processing> An example of shift schedule selection processing performed by the shift control unit 130 will be described. FIG. 7 shows an example of processing executed by the processing unit 131, and shows the periodically executed shift schedule selection processing. This processing is executed regardless of whether ACC is in operation or not.

[0044] In step S11, driving state information is acquired via the I / F 113. In the case of the present embodiment, at least vehicle speed information, throttle opening information, and deceleration information are acquired.

[0045] In step S12, a switching threshold to be compared with the throttle opening is set. The switching threshold is changed according to the vehicle speed. FIG. 8 shows an example of a table 500 for setting the switching threshold. The horizontal axis represents vehicle speed V, and the vertical axis represents the switching threshold. The switching threshold is 0 (corresponding to fully closed) up to vehicle speed V2. In a low vehicle speed region where running resistance is relatively small, fixing the switching threshold to a value corresponding to full closure can prevent the control from becoming complicated.

[0046] After the vehicle speed reaches V2, the switching threshold increases as the vehicle speed V increases. For example, in the example of FIG. 8, the switching threshold corresponding to vehicle speed V4 on the higher vehicle speed side is larger than the switching threshold corresponding to vehicle speed V3. When the vehicle speed is high, when the throttle opening is changed to the closed side, the shift schedule is likely to be switched, which makes it easy to cause a downshift. On the other hand, even if the throttle opening is changed to the open side, it becomes difficult to switch the shift schedule, and the occurrence of deviation between the actual driving state and the selected shift schedule is suppressed.

[0047] In step S13, the throttle opening specified by the throttle opening information acquired in step S11 is compared with the switching threshold set in step S12. If the throttle opening exceeds the switching threshold, the process proceeds to step S18; if the throttle opening is equal to or less than the switching threshold, the process proceeds to step S14.

[0048] In step S14, the deceleration of the vehicle 1 is calculated based on the deceleration information acquired in step S11. In step S15, it is determined whether or not the vehicle 1 is being braked. Here, if the magnitude of the deceleration calculated in step S14 exceeds a threshold, it is determined that the vehicle 1 is being braked. If it is determined that the vehicle 1 is being braked, the process proceeds to step S20; if it is determined that the vehicle 1 is not being braked, the process proceeds to step S16.

[0049] In step S16, the gradient of the traveling road on which the vehicle 1 is traveling is estimated based on the vehicle speed information acquired in step S11. Here, for example, the gradient is estimated based on the degree of increase in the vehicle speed. In step S17, it is determined whether or not the vehicle 1 is traveling on a downhill road based on the estimation result of step S16. If it is determined that the vehicle 1 is traveling on a downhill road, the process proceeds to step S19; if it is determined that the vehicle 1 is not traveling on a downhill road, the process proceeds to step S18.

[0050] In addition to estimating the gradient of the traveling road on which the vehicle 1 is traveling based on vehicle speed information as described above, in step S11, behavior information of the vehicle 1 may be acquired from the inertial sensor 303 via the I / F 113, and the gradient of the traveling road may be estimated from the acquired behavior information of the vehicle 1.

[0051] In step S18, a normal shift schedule is selected. The normal shift schedule is the shift schedule 401 in FIG. 5 as an example. In step S19, a downhill shift schedule is selected. The downhill shift schedule is the shift schedule 402 in FIG. 5 as an example. In step S20, a deceleration shift schedule is selected. The deceleration shift schedule is the shift schedule 403 in FIG. 6 as an example. The process ends with the above steps.

[0052] As described above, in this embodiment, in the control that switches the shift schedule based on the throttle opening, the switching threshold compared with the throttle opening is changed according to the vehicle speed. Therefore, compared to control that switches the shift schedule on the condition that the throttle opening is fully closed, it is possible to prevent the shift schedule from being set by determining that the vehicle 1 has started to accelerate even though the vehicle 1 is not accelerating due to driving resistance, etc. This point will be explained with reference to Figure 15. Figure 15 is a graph showing an example of the relationship between the rotational speed of the engine 21 and the output of the engine 21 due to driving resistance and throttle opening.

[0053] In Figure 15, line L1 shows the output characteristics of engine 21 when the throttle is fully open, and the output increases as the engine speed of engine 21 increases. In other words, it can be said that the output increases as the vehicle speed increases. Line L2 shows the engine braking of engine 21 when the throttle is fully closed, and the larger the engine braking, the larger the negative value. The engine braking also increases as the engine speed of engine 21 increases. In other words, it can be said that the engine braking increases as the vehicle speed increases.

[0054] Line L11 shows, as a reference example, the change in driving resistance when vehicle 1 is traveling on a flat road with the 4th gear ratio selected. Driving resistance increases with increasing vehicle speed, so considering the case where the gear ratio is 4th, it increases as the rotational speed of engine 21 increases.

[0055] As described above, the driving resistance acting on vehicle 1, such as rolling resistance and air resistance, increases as the vehicle speed of vehicle 1 increases, and engine braking also increases as the engine speed increases, that is, as the vehicle speed increases. In addition to these, the vehicle body may also experience effects such as the smoothness of the road surface, gravitational acceleration due to downhill slopes, tailwinds, etc., which can reduce driving resistance and even have an effect in the direction of acceleration. If the shift schedule is simply switched based on whether the throttle opening is fully closed or not, the shift schedule will be set based on the judgment that vehicle 1 has started to accelerate even though vehicle 1 is not accelerating due to driving resistance, etc. As in this embodiment, by changing the switching threshold according to the vehicle speed, such a situation can be prevented, and as a result, a technology can be provided that suppresses discrepancies between the actual driving situation and the shift schedule.

[0056] In this embodiment in particular, the switching threshold takes a relatively large value at higher vehicle speeds and a small value at lower vehicle speeds. The higher the vehicle speed, the easier it is for the shift schedule to switch when the throttle opening is changed to the closed side, making it easier to cause a downshift. On the other hand, even if the throttle opening is changed to the open side, it becomes more difficult for the shift schedule to switch, suppressing the discrepancy between the actual driving situation and the shift schedule. Furthermore, by switching the shift schedule for downhill driving and the shift schedule for deceleration together, it is possible to select a shift schedule that is appropriate for the actual driving situation with high accuracy, taking into account the driving resistance in each situation.

[0057] <Second Embodiment> The table for setting the switching threshold is not limited to the table 500 illustrated in Figure 8. Figure 9 shows an example of another table. Table 501 is configured such that the switching threshold increases in stages as the vehicle speed V increases. The switching threshold is 0 (equivalent to fully closed) up to vehicle speed V2, then increases in value from vehicle speed V2 onwards and remains constant up to vehicle speed V4, after which the value increases again. There is further vehicle speed intervals where the value remains constant, and then the value increases again.

[0058] Table 502 is configured such that the switching threshold increases linearly (in a straight line) as the vehicle speed V increases. The switching threshold is 0 (equivalent to fully closed) up to vehicle speed V2, and from vehicle speed V2 onward, the value increases in proportion to the vehicle speed V.

[0059] Thus, the change in the switching threshold relative to vehicle speed can be designed to have various characteristics to match the vehicle's characteristics.

[0060] <Third Embodiment> The shift schedule may have different parameters for the shift-up schedule and the shift-down schedule. Figure 10 shows an example. The shift schedule 404 shown is an example of a shift-down schedule in which shift-down lines SD1 to SD5 are set, with the horizontal axis being the vehicle speed V and the vertical axis being the downhill gradient SL. In the processing example of Figure 7, the shift schedule 404 is selected as a downhill shift schedule in step S19, and in this case, only the upshift portion of the shift schedule 402 may be selected. Note that in the processing example of Figure 4, when a shift-down is determined based on the shift schedule 404, the downhill gradient SL can be estimated based on the vehicle speed information, similar to the road gradient estimation process in step S16 of Figure 7.

[0061] <Fourth Embodiment> In the first embodiment, the example given was that the same shift schedules 401 to 403 are used regardless of whether ACC is running or not. However, at least some of the shift schedules 401 may be different depending on whether ACC is running or not. For example, two types of shift schedules 401 and 402 may be prepared, one for ACC and one for normal use, and used depending on whether ACC is running or not. The shift schedule for ACC may have at least some of its shift timing set to the high-speed side compared to the shift schedule for normal use.

[0062] <Fifth Embodiment> In situations where the acceleration and deceleration of vehicle 1 are automatically controlled, such as when ACC is running, even if the vehicle speed fluctuations are the same as when the rider manually controls the acceleration and deceleration of vehicle 1, it can cause the rider to feel a great sense of discomfort. Furthermore, compared to situations where the rider is operating the acceleration and deceleration of vehicle 1, the system switches between accelerator and brake operations at a much higher frequency, resulting in frequent changes in the shift schedule within a short period of time. This causes upshifts and downshifts to occur many times in a short period of time, which can further cause discomfort to the rider. Therefore, the presence or absence of the switching threshold table specification may be switched depending on whether or not automatic acceleration and deceleration control is in effect.

[0063] Figures 11 and 12 show an example of another shift schedule selection process performed by the processing unit 131 of the gear shift control unit 130. This process is performed periodically.

[0064] Referring to Figure 11, in step S31, driving state information is acquired via the I / F 113. In this embodiment, at least vehicle speed information, throttle opening information, deceleration information, and ACC information are acquired. ACC information is information indicating whether or not ACC is in operation, and is provided by the driving control unit 110.

[0065] In step S32, it is determined whether or not ACC is currently running based on the ACC information obtained in step S31. If ACC is currently running, the process proceeds to step S33; otherwise, the process proceeds to step S42 (Figure 12).

[0066] In step S33, the gradient of the road is estimated. This is the same process as in step S16. In step S34, based on the estimation in step S33, it is determined whether or not vehicle 1 is traveling downhill. If it is determined that vehicle 1 is traveling downhill, the process proceeds to step S35. If it is determined that vehicle 1 is not traveling downhill, the process proceeds to step S40.

[0067] In step S35, an ACC-specific shift schedule for downhill driving is selected. In step 36, a switching threshold is set. This is the same process as in step S12. In step 37, the throttle opening, identified by the throttle opening information obtained in step S31, is compared with the switching threshold set in step S36. If the throttle opening exceeds the switching threshold, the process proceeds to step S40; if the throttle opening is less than or equal to the switching threshold, the process proceeds to step S38.

[0068] In step S38, the deceleration of vehicle 1 is calculated based on the deceleration information obtained via I / F 113 in step S31. In step S39, it is determined whether or not vehicle 1 is braking. Here, if the magnitude of the deceleration calculated in step S38 exceeds a threshold, it is determined that vehicle 1 is braking. If it is determined that vehicle 1 is braking, the process proceeds to step S42; otherwise, the process proceeds to step S41.

[0069] In step S40, the normal shift schedule is selected. In step S41, the ACC-specific ACC downhill shift schedule selected in step S35 is maintained. In step S42, the deceleration shift schedule is selected in place of the ACC-specific ACC downhill shift schedule selected in step S35.

[0070] Refer to Figure 12. When ACC is not running, the switching threshold is fixed to a value corresponding to a fully closed throttle opening (=0) and is not a value that changes according to the vehicle speed. In step S42, it is determined whether the throttle opening identified by the throttle opening information acquired via I / F 113 in step S31 is fully closed or not. If it is determined that the throttle opening is fully closed, the process proceeds to step S43; if it is determined that it is not fully closed, the process proceeds to step S47.

[0071] In step S43, the deceleration of vehicle 1 is calculated based on the deceleration information acquired via I / F 113 in step S31. In step S44, it is determined whether or not vehicle 1 is braking. Here, if the magnitude of the deceleration calculated in step S43 exceeds a threshold, it is determined that vehicle 1 is braking. If it is determined that vehicle 1 is braking, the process proceeds to step S49; otherwise, the process proceeds to step S45.

[0072] In step S45, the gradient of the road on which vehicle 1 is traveling is estimated based on the vehicle speed information acquired via I / F 113 in step S31. In step S46, it is determined whether or not vehicle 1 is traveling on a downhill road based on the estimation result in step S45. This is the same process as in steps S37 and S38. If it is determined that vehicle 1 is traveling on a downhill road, the process proceeds to step S48. If it is determined that vehicle 1 is not traveling on a downhill road, the process proceeds to step S40.

[0073] In step S47, the normal shift schedule is selected. In step S48, the normal downhill shift schedule is selected. In step S49, the deceleration shift schedule is selected.

[0074] The normal shift schedule selected in steps S39 and S47 is the same shift schedule, and one example is shift schedule 401 in Figure 5. The deceleration shift schedule selected in steps S41 and S49 is the same shift schedule, and one example is shift schedule 403 in Figure 6.

[0075] The shift schedule 411 in Figure 13 shows an example of a normal downhill shift schedule selected in step S48, and the shift schedule 412 in Figure 13 shows an example of an ACC downhill shift schedule selected in step S40. In the example in Figure 13, in shift schedule 412, at least a portion of the upshift lines SU1 to SU5 and the downshift lines SD1 to SD5 are set to the high-speed side. Under the same driving conditions, shift schedule 402 is set to be more prone to downshifts and less prone to upshifts compared to shift schedule 401.

[0076] In this embodiment, there are two types of downhill shift schedules: a normal downhill shift schedule and an ACC downhill shift schedule, which are used depending on whether ACC is running or not. However, it is also possible to use only one type of shift schedule, and the same shift schedule can be used regardless of whether ACC is running or not.

[0077] As described above, in this embodiment, the switching threshold changes according to the vehicle speed while ACC is running, thus preventing frequent shift schedule changes due to opening and closing the throttle. As a result, the occurrence of shift hunting can be suppressed, preventing the rider from feeling uncomfortable. On the other hand, when ACC is not running, the switching threshold is fixed to a value equivalent to fully closed. Shift schedule changes can be generated in response to rider operation.

[0078] <Sixth Embodiment> When it is determined that vehicle 1 is traveling downhill, the switching threshold may be corrected according to the currently selected gear ratio.

[0079] Figure 14 shows an example of another shift schedule selection process performed by the processing unit 131 of the gear shift control unit 130. This process is performed periodically.

[0080] Steps S51 to S57 and S60 to S62 are the same as steps S11 to S17 and S18 to S20 in Figure 7, respectively, so a detailed explanation is omitted here.

[0081] If it is determined in step S57 that vehicle 1 is traveling downhill, the process proceeds to step S58. If it is determined that vehicle 1 is not traveling downhill, the process proceeds to step S60.

[0082] In step S58, a correction is made to increase or decrease the switching threshold based on the gear ratio currently selected (engaged) in the automatic transmission 22 from 1st to 6th gear, as detected by the shift position sensor 305. The smaller the gear ratio (the closer to 6th gear), the higher the switching threshold is, and the larger the gear ratio (the closer to 1st gear), the lower the switching threshold is. The smaller the gear ratio, the more difficult it is for the shift schedule to switch in response to minute changes in throttle opening. The correction of the switching threshold may be performed, for example, by multiplying the switching threshold set in S52 by a coefficient corresponding to the current gear ratio, or a map may be provided in which a switching threshold is set for each gear ratio, and the switching threshold may be read from the map according to the current gear ratio.

[0083] In step S59, the throttle opening, identified by the throttle opening information acquired via the I / F 113 in step S51, is compared with the corrected switching threshold corrected in step S58. If the throttle opening exceeds the corrected switching threshold, the process proceeds to step S60; if the throttle opening is less than or equal to the corrected switching threshold, the process proceeds to step S61.

[0084] <Summary of Embodiments> The above embodiments disclose at least the following saddle-type vehicles.

[0085] Item 1. A saddle-type vehicle (1) comprising: an engine (21); an automatic transmission (22) that shifts the output of the engine (21) at a predetermined gear ratio; the saddle-type vehicle (1) comprising: a selection means (131) that selects one shift schedule from a plurality of shift schedules (401-403) that define the gear ratio according to the driving conditions including the vehicle speed of the saddle-type vehicle (1); and a gear ratio control means (131) that controls the gear ratio of the automatic transmission based on the shift schedule selected by the selection means and the driving conditions; the plurality of shift schedules (401-403) includes a first shift schedule (402) that is selected when it is determined that the throttle opening of the engine is below a threshold; and the threshold is a value that is changed according to the vehicle speed. Compared to control systems that switch the shift schedule based on the condition that the throttle opening is fully closed, this prevents the system from selecting a shift schedule based on the assumption that the vehicle has started accelerating, even though the vehicle is not actually accelerating. As a result, this technology can suppress discrepancies between the actual driving conditions and the selected shift schedule.

[0086] Item 2. A saddle-type vehicle (1) as described in Item 1, comprising determination means (131) for determining whether or not the saddle-type vehicle (1) is traveling on a downhill road, wherein the first shift schedule is selected when it is determined that the throttle opening is below the threshold and the saddle-type vehicle (1) is traveling on a downhill road. According to this embodiment, stable maintenance of vehicle speed can be achieved in shift control on downhill roads where vehicle speed tends to increase.

[0087] Item 3. A saddle-type vehicle (1) as described in Item 1, wherein the threshold is a first value when the vehicle speed is a first vehicle speed, and a second value greater than the first value when the vehicle speed is a second vehicle speed higher than the first vehicle speed. According to this embodiment, in the high-speed range where the negative output of the engine is high, by setting a higher threshold, the engine output can exceed the driving resistance and the vehicle can switch to an appropriate shift schedule after it has started to accelerate, and the discrepancy between the actual driving situation and the shift schedule can be accurately controlled.

[0088] Item 4. A saddle-type vehicle (1) as described in Item 1, characterized in that the threshold value is a value that increases in stages as the vehicle speed increases. According to this embodiment, in the high-speed range where the negative output of the engine is high, by setting a higher threshold value, the engine output can exceed the driving resistance and the vehicle can switch to an appropriate shift schedule after it has started to accelerate, and the discrepancy between the actual driving situation and the shift schedule can be accurately controlled.

[0089] Item 5. A saddle-type vehicle (1) as described in Item 1, characterized in that the threshold value is a value that increases linearly as the vehicle speed increases. According to this embodiment, in the high-speed range where the negative output of the engine is high, by setting a higher threshold value, the engine output can exceed the driving resistance and the vehicle can switch to an appropriate shift schedule after it has started to accelerate, and the discrepancy between the actual driving situation and the shift schedule can be accurately controlled.

[0090] Item 6. A saddle-type vehicle (1) as described in Item 1, characterized in that the threshold value is a value corresponding to the throttle opening being fully closed when the vehicle speed is below a predetermined speed. According to this embodiment, in the low vehicle speed range where the negative output of the engine is relatively small and even if the shift schedule is switched depending on whether the throttle is fully closed or not, a discrepancy between the actual driving conditions and the selected shift schedule is unlikely to occur, the threshold value can be fixed to a value corresponding to fully closed, thereby preventing the control from becoming more complex.

[0091] Item 7. A saddle-type vehicle (1) as described in Item 1, wherein the plurality of shift schedules (401-403) include a second shift schedule (401) selected when it is determined that the throttle opening exceeds the threshold, and the first shift schedule (402) is set to have a higher vehicle speed timing for at least some gear ratios than the second shift schedule (401). According to this embodiment, when the first shift schedule is selected, it becomes less likely that a higher speed gear ratio will be selected, and it is possible to suppress an increase in vehicle speed on downhill roads, etc.

[0092] Item 8. A saddle-type vehicle (1) as described in Item 1, wherein the plurality of shift schedules (401-403) include a second shift schedule (401) selected when it is determined that the throttle opening exceeds a threshold, and the first shift schedule (402) is set to have a lower shift timing on the higher vehicle speed side than the second shift schedule (401) with respect to at least some gear ratios. According to this embodiment, when the first shift schedule is selected, a lower gear ratio is more likely to be selected, and it is possible to suppress an increase in vehicle speed on downhill roads, etc.

[0093] Item 9. A saddle-type vehicle (1) as described in Item 1, characterized in that the shift schedule defines the gear ratio for the vehicle speed and the throttle opening. According to this embodiment, the gear ratio of the automatic transmission can be appropriately set according to the vehicle speed and the throttle opening.

[0094] Item 10. A saddle-type vehicle (1) as described in Item 1, comprising a driving control means (111) capable of performing driving control that automatically accelerates and decelerates the saddle-type vehicle (1), wherein the threshold value is a value that is changed according to the vehicle speed, regardless of whether the driving control is being performed or not. According to this embodiment, it is possible to provide a technology that suppresses the occurrence of shift hunting when the driving control is being performed, and enables the selection of a shift schedule that takes into account the negative output of the engine when the driving control is not being performed.

[0095] Item 11. A saddle-type vehicle (1) as described in Item 10, comprising detection means (301) for detecting a preceding vehicle, wherein the driving control is a control that automatically accelerates and decelerates the saddle-type vehicle (1) to maintain a constant distance between the preceding vehicle and the saddle-type vehicle (1). According to this embodiment, it is possible to provide a technology that suppresses the occurrence of shift hunting caused by frequent switching of accelerator and brake operations by the system while ACC is running.

[0096] Item 12. A saddle-type vehicle (1) as described in Item 1, comprising: a driving control means (111) capable of performing driving control that automatically accelerates and decelerates the saddle-type vehicle (1); and a determination means (131) for determining whether or not the saddle-type vehicle (1) is traveling downhill, wherein the first shift schedule is selected when the driving control is being performed, the throttle opening is determined to be below the threshold, and the saddle-type vehicle (1) is determined to be traveling downhill. According to this embodiment, during the driving control, the occurrence of shift hunting can be suppressed when the saddle-type vehicle is traveling downhill, preventing the rider from feeling any discomfort.

[0097] Item 13. A saddle-type vehicle (1) as described in Item 12, wherein the plurality of shift schedules (401, 403, 411, 412) include a third shift schedule (411) which is selected when the driving control is not being performed, when it is determined that the saddle-type vehicle (1) is driving downhill, and when the throttle opening corresponds to fully closed. According to this embodiment, by switching between the first shift schedule and the third shift schedule depending on whether the driving control is in progress or not, it is possible to prevent discomfort to the rider while suppressing the occurrence of shift hunting when the saddle-type vehicle is driving downhill.

[0098] Item 14. A saddle-type vehicle (1) as described in Item 1, characterized in that the threshold is increased or decreased according to the gear ratio selected in the automatic transmission. According to this embodiment, the vehicle speed can be stably maintained by increasing or decreasing the threshold based on the selected gear ratio.

[0099] Item 15. A saddle-type vehicle (1) as described in Item 2, wherein the threshold is increased or decreased according to the gear ratio selected in the automatic transmission when it is determined that the saddle-type vehicle (1) is traveling downhill. According to this embodiment, in shift control on a downhill road where the vehicle speed tends to increase, the vehicle speed can be stably maintained by increasing or decreasing the threshold based on the selected gear ratio.

[0100] Although embodiments of the invention have been described above, the invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the gist of the invention. Accordingly, in order to make the scope of the present invention public, the following claims are attached.

[0101] 1 Saddle-type vehicle, 21 Engine, 22 Automatic transmission, 130 Shift control unit, 111 Processing unit, 121 Processing unit, 131 Processing unit, 112 Memory unit, 122 Memory unit, 132 Memory unit, 113 Interface (I / F), 123 Interface (I / F), 133 Interface (I / F), 200 Input unit, 301 External sensor, 302 Vehicle speed sensor, 303 Inertia sensor, 304 Throttle opening sensor, 305 Shift position sensor

Claims

1. A saddle-type vehicle (1) comprising: an engine (21); an automatic transmission (22) that shifts the output of the engine (21) at a predetermined gear ratio; a selection means (131) that selects one shift schedule from a plurality of shift schedules (401-403) that define the gear ratio according to the driving conditions including the vehicle speed of the saddle-type vehicle (1); and a gear ratio control means (131) that controls the gear ratio of the automatic transmission based on the shift schedule selected by the selection means and the driving conditions; wherein the plurality of shift schedules (401-403) include a first shift schedule (402) that is selected when it is determined that the throttle opening of the engine is below a threshold; and the threshold is a value that changes according to the vehicle speed.

2. A saddle-type vehicle (1) according to claim 1, comprising determination means (131) for determining whether or not the saddle-type vehicle (1) is traveling on a downhill road, wherein the first shift schedule is selected when it is determined that the throttle opening is less than or equal to the threshold and that the saddle-type vehicle (1) is traveling on a downhill road.

3. A saddle-type vehicle (1) according to claim 1, characterized in that the threshold is a first value when the vehicle speed is a first vehicle speed, and a second value greater than the first value when the vehicle speed is a second vehicle speed higher than the first vehicle speed.

4. A saddle-type vehicle (1) according to claim 1, characterized in that the threshold value is a value that increases in stages as the vehicle speed increases.

5. A saddle-type vehicle (1) according to claim 1, characterized in that the threshold value is a value that increases linearly as the vehicle speed increases.

6. A saddle-type vehicle (1) according to claim 1, characterized in that the threshold is a value that corresponds to the throttle opening being fully closed when the vehicle speed is below a predetermined speed.

7. A saddle-type vehicle (1) according to claim 1, wherein the plurality of shift schedules (401-403) include a second shift schedule (401) selected when it is determined that the throttle opening exceeds the threshold, and the first shift schedule (402) is set to have a higher shift-up timing than the second shift schedule (401) with respect to at least some gear ratios.

8. A saddle-type vehicle (1) according to claim 1, wherein the plurality of shift schedules (401-403) include a second shift schedule (401) selected when it is determined that the throttle opening exceeds a threshold, and the first shift schedule (402) is set to have a lower shift timing at higher vehicle speeds than the second shift schedule (401) with respect to at least some gear ratios.

9. A saddle-type vehicle (1) according to claim 1, characterized in that the shift schedule defines a gear ratio with respect to the vehicle speed and the throttle opening.

10. A saddle-type vehicle (1) according to claim 1, comprising a driving control means (111) capable of performing driving control to automatically accelerate and decelerate the saddle-type vehicle (1), wherein the threshold is a value that is changed according to the vehicle speed, regardless of whether the driving control is being performed or not.

11. A saddle-type vehicle (1) according to claim 10, comprising detection means (301) for detecting a preceding vehicle, wherein the driving control is a control that automatically accelerates and decelerates the saddle-type vehicle (1) so as to maintain a constant distance between the preceding vehicle and the saddle-type vehicle (1).

12. A saddle-type vehicle (1) according to claim 1, comprising: a driving control means (111) capable of performing driving control to automatically accelerate and decelerate the saddle-type vehicle (1); and a determination means (131) for determining whether or not the saddle-type vehicle (1) is traveling downhill, wherein the first shift schedule is selected when the driving control is being performed, the throttle opening is determined to be below the threshold, and the saddle-type vehicle (1) is determined to be traveling downhill.

13. A saddle-type vehicle (1) according to claim 12, wherein the plurality of shift schedules (401, 403, 411, 412) include a third shift schedule (411) that is selected when the driving control is not being performed, when it is determined that the saddle-type vehicle (1) is traveling down a slope, and when the throttle opening corresponds to fully closed.

14. A saddle-type vehicle (1) according to claim 1, characterized in that the threshold is increased or decreased according to the gear ratio selected in the automatic transmission.

15. A saddle-type vehicle (1) according to claim 2, characterized in that the threshold is increased or decreased according to the gear ratio selected in the automatic transmission when it is determined that the saddle-type vehicle (1) is traveling on a downhill road.

Images