Control device for human-powered vehicles

Abstract

To provide a control device for a human-powered vehicle capable of suitably controlling a transmission.SOLUTION: A control device for a human-powered vehicle comprises a control unit that controls a transmission for changing a speed change ratio being a ratio of a rotation speed of wheels of the human-powered vehicle with respect to a rotation speed of a crank shaft of the human-powered vehicle. When a rotation speed of the crank shaft comes to fall outside a first range to outside the first range from within the first range, the control unit controls the transmission so as to change the speed change ratio. A first threshold value that defines the first range for a case that the speed change ratio is equal to or less than a first speed change ratio, is different from a first threshold value for a case that the speed change ratio is larger than the first speed change ratio.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for a human-powered vehicle. [Background technology]

[0002] For example, a control device for a human-powered vehicle disclosed in Patent Document 1 controls a transmission that changes the gear ratio of the human-powered vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-47085 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a control device for a human-powered vehicle that can suitably control a transmission. [Means for solving the problem]

[0005] A control device according to a first aspect of the present invention is a control device for a human-powered vehicle, and includes a control unit that controls a transmission to change a gear ratio, which is the ratio of the rotational speed of the wheels of the human-powered vehicle to the rotational speed of the crankshaft of the human-powered vehicle, and the control unit controls the transmission to change the gear ratio when the rotational speed of the crankshaft goes from within a first range to outside the first range, and a first threshold value that defines the first range when the gear ratio is equal to or less than the first gear ratio is different from the first threshold value when the gear ratio is greater than the first gear ratio. According to the control device of the first aspect, it is possible to use an appropriate first threshold value when the gear ratio is equal to or less than the first gear ratio and when the gear ratio is greater than the first gear ratio, thereby making it possible to control the transmission in an appropriate manner.

[0006] In a control device of a second aspect according to the first aspect, a first threshold value that defines the first range when the gear ratio is equal to or less than a first gear ratio is greater than the first threshold value when the gear ratio is greater than the first gear ratio. According to the control device of the second aspect, the first threshold value that defines the first range when the gear ratio is equal to or smaller than the first gear ratio can be greater than the first threshold value when the gear ratio is greater than the first gear ratio.

[0007] In the control device of a third aspect according to the first or second aspect, the control unit changes the first threshold value in accordance with a load of a rider of the human-powered vehicle. According to the control device of the third aspect, it is possible to use a first threshold value that is suitable for the load of the rider.

[0008] In the control device of a fourth aspect according to the third aspect, the first threshold value when the rider load is equal to or greater than a predetermined load and the gear ratio is the first gear ratio is greater than the first threshold value when the rider load is less than the predetermined load and the gear ratio is the first gear ratio. According to the control device of the fourth aspect, the first threshold value when the rider load is equal to or greater than a predetermined load and the gear ratio is the first gear ratio can be made larger than the first threshold value when the rider load is less than the predetermined load and the gear ratio is the first gear ratio.

[0009] In the control device of a fifth aspect according to the third or fourth aspect, the control unit changes the first threshold value in accordance with a load of the rider over a predetermined period of time. According to the control device of the fifth aspect, the first threshold value can be changed in accordance with the load of the rider over a predetermined period of time.

[0010] In the control device of the sixth aspect according to any one of the third to fifth aspects, the load of the rider includes a human-powered driving force input by the rider to the human-powered vehicle. According to the control device of the sixth aspect, the first threshold value can be changed in accordance with the manual driving force.

[0011] In the control device of a seventh aspect according to the sixth aspect, the human-powered driving force includes torque input by the rider to the crankshaft of the human-powered vehicle in the rotational direction of the crankshaft. According to the control device of the seventh aspect, the first threshold value can be changed in accordance with the torque input to the crankshaft of the human-powered vehicle by the rider in the rotational direction of the crankshaft.

[0012] In the control device of an eighth aspect according to any one of the first to seventh aspects, the first threshold value when the gear ratio is equal to or smaller than the first gear ratio increases as the gear ratio decreases. According to the control device of the eighth aspect, the first threshold value when the gear ratio is equal to or less than the first gear ratio can be made larger the smaller the gear ratio.

[0013] In the control device of a ninth aspect according to any one of the first to eighth aspects, the control unit controls the transmission to increase the gear ratio when the rotational speed of the crankshaft goes from within the first range to outside the first range. According to the control device of the ninth aspect, when the rotation speed of the crankshaft goes from within the first range to outside the first range, the transmission can be controlled to increase the speed ratio.

[0014] In the control device of a tenth aspect according to the ninth aspect, the upper limit of the first range is defined by the first threshold value, and the control unit controls the transmission to increase the gear ratio when the rotational speed of the crankshaft becomes greater than the first threshold value. According to the control device of the tenth aspect, when the rotation speed of the crankshaft becomes greater than the first threshold, the transmission is controlled to increase the gear ratio, thereby suppressing an increase in the rotation speed of the crankshaft and thereby suppressing a decrease in the rider's load.

[0015] In the control device of an eleventh aspect according to any one of the first to tenth aspects, the control unit controls the transmission to reduce the gear ratio when the rotational speed of the crankshaft changes from within a second range to outside the second range. According to the control device of the eleventh aspect, when the rotation speed of the crankshaft goes from within the second range to outside the second range, the transmission can be controlled to reduce the speed ratio.

[0016] In the control device of a twelfth aspect according to the eleventh aspect, the lower limit of the second range is defined by a second threshold value, and the control unit controls the transmission to reduce the gear ratio when the rotational speed of the crankshaft becomes smaller than the second threshold value. According to the control device of the twelfth aspect, when the rotation speed of the crankshaft becomes lower than the second threshold, the transmission is controlled to reduce the gear ratio, thereby suppressing a decrease in the rotation speed of the crankshaft and thus suppressing an increase in the load on the rider.

[0017] In the control device of a thirteenth aspect according to the twelfth aspect, the second threshold value when the gear ratio is equal to or smaller than the first gear ratio is equal to the second threshold value when the gear ratio is greater than the first gear ratio. According to the control device of the thirteenth aspect, the transmission can be controlled using the same second threshold value when the gear ratio is equal to or smaller than the first gear ratio and when the gear ratio is greater than the first gear ratio.

[0018] In the control device of a fourteenth aspect according to any one of the first to thirteenth aspects, the control unit changes the gear ratio to a second gear ratio in at least one of a case where the human-powered vehicle stops traveling and a case where the human-powered vehicle resumes traveling, and the first gear ratio is equal to or less than the second gear ratio. According to the control device of the fourteenth aspect, when the gear ratio is equal to or less than the second gear ratio, the first threshold value can be made different when the gear ratio is equal to or less than the first gear ratio and when the gear ratio is greater than the first gear ratio. [Effects of the Invention]

[0019] The control device for a human-powered vehicle of the present disclosure can suitably control the transmission. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side view of a human-powered vehicle including a control device for a human-powered vehicle according to a first embodiment. [Figure 2] 1 is a block diagram showing the electrical configuration of a human-powered vehicle including a control device for a human-powered vehicle according to a first embodiment. [Figure 3] 3 is a flowchart of a process executed by the control unit of FIG. 2 to control the transmission. DETAILED DESCRIPTION OF THE INVENTION

[0021] <Embodiment> A control device 50 for a human-powered vehicle according to an embodiment will be described with reference to FIGS. 1 to 3. The human-powered vehicle 10 is a vehicle that has at least one wheel and can be driven at least by human driving force. Examples of the human-powered vehicle 10 include various types of bicycles, such as mountain bikes, road bikes, city bikes, cargo bikes, hand bikes, and recumbent bikes. The number of wheels that the human-powered vehicle 10 has is not limited. Examples of the human-powered vehicle 10 include unicycles and vehicles with three or more wheels. The human-powered vehicle 10 is not limited to vehicles that can be driven solely by human driving force H. Examples of the human-powered vehicle 10 include e-bikes that use not only human driving force H but also the driving force of an electric motor for propulsion. E-bikes include electrically assisted bicycles whose propulsion is assisted by an electric motor. In the following embodiments, the human-powered vehicle 10 will be described as a bicycle.

[0022] The human-powered vehicle 10 includes a crank 12 to which a human-powered driving force H is input. The human-powered vehicle 10 further includes wheels 14 and a vehicle body 16. The wheels 14 include a rear wheel 14A and a front wheel 14B. The vehicle body 16 includes a frame 18. The crank 12 includes a crankshaft 12A that is rotatable relative to the frame 18 and a pair of crank arms 12B that are respectively provided at axial ends of the crankshaft 12A. A pair of pedals 20 are respectively connected to each crank arm 12B. The rear wheel 14A is driven by rotation of the crank 12. The rear wheel 14A is supported by the frame 18. The crank 12 is connected to the rear wheel 14A by a drive mechanism 22. The drive mechanism 22 includes a first rotor 24 that is connected to the crankshaft 12A. The crankshaft 12A may be connected to the first rotating body 24 so as to rotate integrally with it, or may be connected to it via a first one-way clutch. The first one-way clutch is configured to rotate the first rotating body 24 forward when the crank 12 rotates forward, and to allow relative rotation between the crank 12 and the first rotating body 24 when the crank 12 rotates backward. The first rotating body 24 includes a sprocket, a pulley, or a bevel gear. The drive mechanism 22 further includes a second rotating body 26 and a connecting member 28. The connecting member 28 transmits the rotational force of the first rotating body 24 to the second rotating body 26. The connecting member 28 includes, for example, a chain, a belt, or a shaft.

[0023] The second rotating body 26 is connected to the rear wheel 14A. The second rotating body 26 includes a sprocket, a pulley, or a bevel gear. A second one-way clutch is preferably provided between the second rotating body 26 and the rear wheel 14A. The second one-way clutch is configured to rotate the rear wheel 14A forward when the second rotating body 26 rotates forward, and to allow relative rotation between the second rotating body 26 and the rear wheel 14A when the second rotating body 26 rotates backward.

[0024] A front wheel 14B is attached to the frame 18 via a front fork 30. A handlebar 34 is connected to the front fork 30 via a stem 32. In this embodiment, the rear wheel 14A is connected to the crank 12 by the drive mechanism 22, but at least one of the rear wheel 14A and the front wheel 14B may be connected to the crank 12 by the drive mechanism 22.

[0025] The human-powered vehicle 10 includes a transmission 36. The transmission 36 changes a transmission ratio R, which is the ratio of the rotational speed W of the wheels 14 of the human-powered vehicle 10 to the rotational speed C of the crankshaft 12A of the human-powered vehicle 10. The transmission ratio R is the ratio of the rotational speed of the drive wheel to the rotational speed C of the crankshaft 12A. In this embodiment, the drive wheel is the rear wheel 14A. The transmission 36 includes, for example, at least one of a front derailleur, a rear derailleur, and an internal gearbox. When the transmission 36 includes an internal gearbox, the internal gearbox is provided, for example, in the hub of the rear wheel 14A. The transmission 36 is configured to be operated by an actuator 38. The actuator 38 includes an electric actuator. The actuator 38 includes, for example, an electric motor.

[0026] The control device 50 includes a control unit 52. The control unit 52 includes an arithmetic processing unit that executes a predetermined control program. The arithmetic processing unit includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The arithmetic processing units may be provided in multiple locations that are separate from one another. The control unit 52 may include one or more microcomputers. Preferably, the control device 50 further includes a memory unit 54. The memory unit 54 stores various control programs and information used for various control processes. The memory unit 54 includes, for example, a nonvolatile memory and a volatile memory. The nonvolatile memory includes, for example, at least one of a ROM (Read-Only Memory), an EPROM (Erasable Programmable Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), and a flash memory. The volatile memory includes, for example, a RAM (Random Access Memory).

[0027] Preferably, the human-powered vehicle 10 includes a crank rotation sensor 40. The crank rotation sensor 40 is configured to detect information corresponding to the rotation speed C of the crankshaft 12A. The crank rotation sensor 40 is mounted, for example, on the frame 18 of the human-powered vehicle 10. The crank rotation sensor 40 includes a magnetic sensor that outputs a signal corresponding to the strength of a magnetic field. An annular magnet, whose magnetic field strength varies circumferentially, is mounted on the crankshaft 12A, a member that rotates in conjunction with the crankshaft 12A, or the power transmission path from the crankshaft 12A to the first rotating body 24. The crank rotation sensor 40 outputs a signal corresponding to the rotation speed C of the crankshaft 12A. The magnet may be mounted on a member that rotates integrally with the crankshaft 12A in the power transmission path of the human-powered driving force H from the crankshaft 12A to the first rotating body 24. For example, if a first one-way clutch is not provided between the crankshaft 12A and the first rotating body 24, the magnet may be provided on the first rotating body 24. The crank rotation sensor 40 may include an optical sensor, an acceleration sensor, a gyro sensor, or a torque sensor instead of a magnetic sensor. The crank rotation sensor 40 is connected to the control unit 52 via a wireless communication device or an electric cable. Preferably, the crank rotation sensor 40 is configured to output a detection signal a predetermined number of times during one rotation of the crank 12. The predetermined number is, for example, two or more. Preferably, the predetermined number is four or more. The predetermined number is preferably a multiple of four. Preferably, the predetermined number is 8, 12, or 16. The crank rotation sensor 40 may be configured to include a vehicle speed sensor. If the crank rotation sensor 40 includes a vehicle speed sensor, for example, the control unit 52 is configured to calculate the rotation speed C of the crankshaft 12A based on the vehicle speed detected by the vehicle speed sensor and the gear ratio R.

[0028] Preferably, the human-powered vehicle 10 includes a torque sensor 42. The torque sensor 42 is configured to output a signal corresponding to the torque applied to the crank 12 by the human-powered driving force H. For example, if a first one-way clutch is provided in the power transmission path, the torque sensor 42 is preferably provided upstream of the first one-way clutch in the power transmission path. The torque sensor 42 includes a strain sensor, a magnetostrictive sensor, or a pressure sensor. The strain sensor includes a strain gauge. The torque sensor 42 is provided in the power transmission path or in a component included in the power transmission path or in the vicinity of a component included in the power transmission path. The component included in the power transmission path is, for example, the crankshaft 12A, a component that transmits the human-powered driving force H between the crankshaft 12A and the first rotor 24, the crank arm 12B, or the pedal 20. The torque sensor 42 is connected to the control unit 52 via a wireless communication device or an electric cable. The torque sensor 42 may have any configuration as long as it can acquire information about the manual driving force H, and may include, for example, a sensor that detects the pressure applied to the pedal 20 or a sensor that detects the tension of the chain.

[0029] The control unit 52 controls the transmission 36. When the rotation speed C of the crankshaft 12A changes from within a first range W1 to outside the first range W1, the control unit 52 controls the transmission 36 to change the gear ratio R. The first range W1 is defined by a first threshold value C1. In this embodiment, the upper limit of the first range W1 is defined by the first threshold value C1. The first range W1 includes a range equal to or less than the first threshold value C1. When the rotation speed C of the crankshaft 12A changes from within the first range W1 to outside the first range W1, the control unit 52 controls the transmission 36 to increase the gear ratio R. When the rotation speed C of the crankshaft 12A becomes greater than the first threshold value C1, the control unit 52 controls the transmission 36 to increase the gear ratio R. When the rotation speed C of the crankshaft 12A is greater than the first threshold value C1, the control unit 52 increases the gear ratio R, thereby increasing the rider's load. Therefore, the rotation speed C of the crankshaft 12A tends to become equal to or less than the first threshold value C1.

[0030] The first threshold value C1 that defines the first range W1 when the gear ratio R is equal to or less than the first gear ratio R1 is different from the first threshold value C1 when the gear ratio R is greater than the first gear ratio R1. Preferably, the first threshold value C1 that defines the first range W1 when the gear ratio R is equal to or less than the first gear ratio R1 is greater than the first threshold value C1 when the gear ratio R is greater than the first gear ratio R1.

[0031] Preferably, the control unit 52 changes the gear ratio R to the second gear ratio R2 at least one of when the human-powered vehicle 10 stops traveling and when the human-powered vehicle 10 resumes traveling. Preferably, the first gear ratio R1 is equal to or less than the second gear ratio R2.

[0032] Table 1 shows a first example of the relationship between a transmission 36 that can change the gear ratio R in 12 stages and the first threshold value C1. The gear ratio R increases as the gear stage increases. The gear ratio RA5 for the fifth stage shown in Table 1 corresponds to the second gear ratio R2. The gear ratios RA1 to RA4 for the first to fourth stages shown in Table 1 correspond to the first gear ratio R1. In Table 1, when the gear ratio R is equal to or greater than the gear ratio RA5, the first threshold value C1 is the reference value CA. In Table 1, when the gear ratio R is smaller than the gear ratio RA5, the first threshold value C1 is the value obtained by adding the first value CX to the reference value CA. The reference value CA in Table 1 is, for example, 80 rpm. The first value CX in Table 1 is, for example, 30 rpm.

[0033] [Table 1]

[0034] The control unit 52 may change the first threshold C1 in accordance with the load L of the rider of the human-powered vehicle. Preferably, the load L of the rider includes a human-powered driving force H input by the rider to the human-powered vehicle 10. Preferably, the human-powered driving force H includes a torque HT input by the rider to the crankshaft 12A of the human-powered vehicle 10 in the rotational direction of the crankshaft 12A.

[0035] For example, the first threshold C1 when the rider's load L is equal to or greater than the predetermined load LX and the gear ratio R is the first gear ratio R1 is greater than the first threshold C1 when the rider's load L is less than the predetermined load LX and the gear ratio R is the first gear ratio R1. Preferably, the control unit 52 changes the first threshold C1 according to the rider's load L during the predetermined period TX. The control unit 52 calculates the rider's load L, for example, at each predetermined cycle. The predetermined cycle is, for example, the detection cycle of the torque sensor 42. The predetermined cycle may be longer than the detection cycle of the torque sensor 42. For example, the control unit 52 determines that the rider's load L is less than the predetermined load LX if the rider's load L is less than the predetermined load LX multiple times consecutively within multiple predetermined cycles. For example, the control unit 52 determines that the rider's load L is less than the predetermined load LX if the load L is less than the predetermined load LX a predetermined number of times or more among the multiple predetermined cycles.

[0036] Table 2 shows a second example of the relationship between the transmission 36, which can change the gear ratio R in 12 stages, and the first threshold value C1. The gear ratio RA5 for the fifth stage shown in Table 2 corresponds to the second gear ratio R2. The gear ratios RA1 to RA4 for the first to fourth stages shown in Table 2 correspond to the first gear ratio R1. In Table 2, when the gear ratio R is equal to or greater than the gear ratio RA5, the first threshold value C1 is the reference value CA regardless of the magnitude of the load L. In Table 2, when the gear ratio R is smaller than the gear ratio RA5 and the load L is smaller than a predetermined load LX, the first threshold value C1 is the reference value CA. In Table 2, when the gear ratio R is smaller than the gear ratio RA5 and the load L is equal to or greater than the predetermined load LX, the first threshold value C1 is the value obtained by adding a second value CY to the reference value CA. The reference value CA in Table 2 is, for example, 80 rpm. The second value CY in Table 2 is, for example, 10 rpm. The predetermined load LX in Table 2 is, for example, 10 Nm or more and 70 Nm or less. The predetermined load LX in Table 2 is, for example, 25 Nm or more and 45 Nm or less.

[0037] [Table 2]

[0038] Table 3 shows a third example of the relationship between the transmission 36, which can change the gear ratio R in 12 stages, and the first threshold value C1. The gear ratio RA5 for the fifth stage shown in Table 3 corresponds to the second gear ratio R2. The gear ratios RA1 to RA4 for the first to fourth stages shown in Table 3 correspond to the first gear ratio R1. In Table 3, when the gear ratio R is equal to or greater than the gear ratio RA5, the first threshold value C1 is the reference value CA regardless of the magnitude of the load L. In Table 3, when the gear ratio R is smaller than the gear ratio RA5, and when the load L is smaller than the predetermined load LX, and when the load L is smaller than the first load LY, the first threshold value C1 is the reference value CA plus the third value CZ. In Table 3, when the gear ratio R is smaller than the gear ratio RA5, when the load L is smaller than the predetermined load LX, and when the load L is equal to or greater than the first load LY, the first threshold C1 is a value obtained by adding the fifth value CW to the reference value CA. Preferably, the fourth value CV is greater than the third value CZ. Preferably, the fifth value CW is greater than the fourth value CV. The reference value CA in Table 3 is, for example, 80 rpm. The third value CZ in Table 3 is, for example, 5 rpm. The fourth value CV in Table 3 is, for example, 10 rpm. The fifth value CW in Table 3 is, for example, 20 rpm. The predetermined load LX in Table 3 is, for example, 0 Nm or more and 30 Nm or less. The predetermined load LX in Table 3 is, for example, 5 Nm or more and 15 Nm or less. The first load LY in Table 3 is, for example, 5 Nm or more and 70 Nm or less. The predetermined load LX in Table 3 is, for example, 10 Nm or more and 45 Nm or less.

[0039] [Table 3]

[0040] The first threshold C1 when the gear ratio R is equal to or less than the first gear ratio R1 may be larger as the gear ratio R is smaller. Table 4 shows an example of the relationship between the gear ratio R, the load L, and the first threshold C1 when the gear ratio R is equal to or less than the first gear ratio R1, in which the first threshold C1 becomes larger as the gear ratio R becomes smaller. The predetermined load LX in Table 4 is, for example, 0 Nm or more and 30 Nm or less. The predetermined load LX in Table 4 is, for example, 5 Nm or more and 15 Nm or less. The first load LY in Table 4 is, for example, 5 Nm or more and 70 Nm or less. The predetermined load LX in Table 4 is, for example, 10 Nm or more and 45 Nm or less.

[0041] [Table 4]

[0042] Preferably, the control unit 52 controls the transmission 36 to reduce the gear ratio R when the rotation speed C of the crankshaft 12A changes from within the second range W2 to outside the second range W2. The second range W2 is defined by a second threshold value C2. In this embodiment, the lower limit of the second range W2 is defined by the second threshold value C2. The second range W2 includes a range equal to or greater than the second threshold value C2. The control unit 52 controls the transmission 36 to reduce the gear ratio R when the rotation speed C of the crankshaft 12A becomes smaller than the second threshold value C2. When the rotation speed C of the crankshaft 12A is smaller than the second threshold value C2, the control unit 52 reduces the gear ratio R, thereby reducing the rider's load. Therefore, the rotation speed C of the crankshaft 12A is more likely to become equal to or greater than the second threshold value C2.

[0043] Preferably, the second threshold value C2 when the gear ratio R is equal to or less than the first gear ratio R1 is equal to the second threshold value C2 when the gear ratio R is greater than the first gear ratio R1. In the case of a transmission 36 in which the gear ratio R can be changed in multiple stages, preferably, the second threshold value C2 is equal in all stages. The second threshold value C2 is, for example, 60 rpm.

[0044] The process of controlling the transmission 36 will be described with reference to Fig. 3. When power is supplied to the control unit 52, the control unit 52 starts the process and proceeds to step S11 of the flowchart shown in Fig. 3. When the flowchart of Fig. 3 ends, the control unit 52 repeats the process from step S11 after a predetermined period until the supply of power is stopped.

[0045] In step S11, the control unit 52 determines whether the human-powered vehicle 10 has started or stopped running. The control unit 52 determines whether the human-powered vehicle 10 has started or stopped running, for example, in accordance with at least one of the rotation speed C of the crankshaft 12A and the vehicle speed of the human-powered vehicle 10. If the control unit 52 determines in step S11 that the human-powered vehicle 10 has started or stopped running, the control unit 52 proceeds to step S12.

[0046] In step S12, the control unit 52 determines whether the gear ratio R is the second gear ratio R2. If the gear ratio R is the second gear ratio R2, the control unit 52 ends the processing. If the gear ratio R is not the second gear ratio R2, the control unit 52 proceeds to step S13. In step S13, the control unit 52 controls the transmission 36 to change the gear ratio R to the second gear ratio R2, and ends the processing.

[0047] If the human-powered vehicle 10 has not started or stopped traveling in step S11, i.e., if the human-powered vehicle 10 is traveling, the control unit 52 proceeds to step S14. In step S14, the control unit 52 sets a first threshold value C1, and proceeds to step S15. For example, the control unit 52 calculates the first threshold value C1 according to the gear ratio R and the load L using one of Tables 1, 2, 3, and 4, and defines the first range W1 using the calculated first threshold value C1.

[0048] In step S15, the control unit 52 determines whether the rotation speed C of the crankshaft 12A is outside the first range W1. If the rotation speed C of the crankshaft 12A is greater than the first threshold value C1, the control unit 52 determines that the rotation speed C of the crankshaft 12A is outside the first range W1. In step S15, the control unit 52 performs a determination process using the first threshold value C1 set in step S14. If the rotation speed C of the crankshaft 12A is outside the first range W1, the control unit 52 proceeds to step S16. In step S16, the control unit 52 controls the transmission 36 to increase the gear ratio R, and then ends the process.

[0049] If the rotation speed C of the crankshaft 12A is not outside the first range W1 in step S15, the control unit 52 proceeds to step S17. In step S17, the control unit 52 determines whether the rotation speed C of the crankshaft 12A is outside the second range W2. If the rotation speed C of the crankshaft 12A is smaller than the second threshold value C2, the control unit 52 determines that the rotation speed C of the crankshaft 12A is outside the second range W2. If the rotation speed C of the crankshaft 12A is outside the second range W2, the control unit 52 proceeds to step S18. In step S18, the control unit 52 controls the transmission 36 to reduce the gear ratio R, and then ends the process.

[0050] The control unit 52 sets the first threshold C1, which defines the upper limit of the first range W1 when the gear ratio R is equal to or less than the first gear ratio R1, to be larger than the first threshold C1 when the gear ratio R is greater than the first gear ratio R1. Therefore, when the gear ratio R is small, the gear ratio R is less likely to become large. For example, when the human-powered vehicle 10 travels uphill with a steep gradient, the human-powered vehicle 10 is likely to travel with the gear ratio R equal to or less than the first gear ratio R1. When the human-powered vehicle 10 travels with the gear ratio R equal to or less than the first gear ratio R1, for example, immediately after going over a bump in the road surface, the rider's load L decreases, and the rotation speed C of the crankshaft 12A is likely to increase. When the gear ratio R is equal to or less than the first gear ratio R1, the control unit 52 sets the first threshold C1 to be larger, and therefore the gear ratio R is less likely to become large even if the rotation speed C of the crankshaft 12A increases.

[0051] The control unit 52 sets the first threshold value C1 when the rider's load L is equal to or greater than the predetermined load LX and the gear ratio R is the first gear ratio R1 higher than the first threshold value C1 when the rider's load L is less than the predetermined load LX and the gear ratio R is the first gear ratio R1. Therefore, when the human-powered vehicle 10 is traveling with the gear ratio R being equal to or less than the first gear ratio R1, the greater the rider's load L is above the predetermined load LX, the less likely it is that the gear ratio R will become large unless the rotation speed C of the crankshaft 12A increases. For example, when the human-powered vehicle 10 goes over a bump in the road surface, the rider's load L is likely to become larger than the predetermined load LX. When the gear ratio R is equal to or less than the first gear ratio R1 and the rider's load L is greater than a predetermined load LX, and the human-powered vehicle 10 is traveling, for example, immediately after going over a bump in the road surface, the rider's load L decreases, and the rotation speed C of the crankshaft 12A is likely to increase. When the gear ratio R is equal to or less than the first gear ratio R1 and the rider's load L is greater than the predetermined load LX, the control unit 52 increases the first threshold C1, so that the gear ratio R is less likely to increase even if the rotation speed C of the crankshaft 12A increases.

[0052] Since the control unit 52 changes the first threshold C1 according to the rider's load L during the predetermined period TX, for example, if the rider's load L temporarily decreases immediately after riding over a bump on the road surface, the first threshold C1 is unlikely to decrease. This makes it possible to prevent the gear ratio R from being changed due to a temporary decrease in the rider's load L.

[0053] <Modification> The descriptions of the embodiments are examples of possible forms of a control device for a human-powered vehicle according to the present disclosure, and are not intended to limit the forms. A control device for a human-powered vehicle according to the present disclosure can take the form of, for example, a modified version of the embodiment shown below, or a combination of at least two mutually consistent modified versions. In the following modified versions, parts that are common to the embodiment will be assigned the same reference numerals as in the embodiment, and their description will be omitted.

[0054] The first threshold C1 may be a value that defines the lower limit of the first range W1. In this case, the second threshold C2 is preferably a value that defines the upper limit of the second range W2.

[0055] The second threshold C2 when the gear ratio R is equal to or less than the first gear ratio R1 may be different from the second threshold C2 when the gear ratio R is greater than the first gear ratio R1. For example, the second threshold C2 when the gear ratio R is equal to or less than the first gear ratio R1 is greater than the second threshold C2 when the gear ratio R is greater than the first gear ratio R1. For example, the second threshold C2 when the gear ratio R is equal to or less than the first gear ratio R1 is smaller than the second threshold C2 when the gear ratio R is greater than the first gear ratio R1.

[0056] The rider's load L may include the gradient of the road on which the human-powered vehicle 10 is traveling. In this case, for example, the human-powered vehicle 10 is equipped with an inclination angle detection unit. The inclination angle detection unit includes, for example, an inclination sensor and a GPS device that can acquire the road gradient of the road. The control unit 52 calculates the road gradient based on the signal input from the inclination angle detection unit and changes the first threshold C1 based on the road gradient.

[0057] The human-powered driving force H may be a force input to the crank arm 12B of the human-powered vehicle 10 by the rider, or may be a force input to the pedal 20.

[0058] The phrase "at least one" as used herein means "one or more" of the desired options. As an example, the phrase "at least one" as used herein means "only one option" or "both of two options" when the number of options is two. As another example, the phrase "at least one" as used herein means "only one option" or "any combination of two or more options" when the number of options is three or more. [Explanation of symbols]

[0059] 10...human-powered vehicle, 12A...crankshaft, 14...wheel, 36...transmission, 50...control device, 52...control unit.

Claims

1. A control device for a human-powered vehicle, a control unit that controls a transmission that changes a gear ratio, which is a ratio of a rotational speed of a wheel of the human-powered vehicle to a rotational speed of a crankshaft of the human-powered vehicle, the control unit controls the transmission to change the gear ratio in accordance with a value corresponding to a rotational speed of the crankshaft that is determined based on a vehicle speed detected by a vehicle speed sensor and the gear ratio; a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or smaller than a first gear ratio is greater than a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is greater than the first gear ratio.

2. A control device as described in claim 1, wherein a value equivalent to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or less than the first gear ratio, and the load of the rider of the human-powered vehicle is greater than a value equivalent to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is greater than the first gear ratio, and the load of the rider.

3. A control device for a human-powered vehicle, a control unit that controls a transmission that changes a gear ratio, which is a ratio of a rotational speed of a wheel of the human-powered vehicle to a rotational speed of a crankshaft of the human-powered vehicle, the control unit controls the transmission to change the gear ratio in accordance with a value corresponding to a rotational speed of the crankshaft that is determined based on a vehicle speed detected by a vehicle speed sensor and the gear ratio; a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or less than a first gear ratio is different from a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is greater than the first gear ratio, a load on a rider of the human-powered vehicle when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or less than the first gear ratio is greater than a load on the rider of the human-powered vehicle when the control unit controls the transmission to increase the gear ratio when the gear ratio is greater than the first gear ratio.

4. A control device as described in claim 2 or 3, wherein the rider's load is the rider's load over a predetermined period of time.

5. The control device according to claim 2 , wherein the load of the rider includes a human-powered driving force input to the human-powered vehicle by the rider.

6. The control device according to claim 5 , wherein the manual driving force includes torque input to the crankshaft by the rider in a rotational direction of the crankshaft.

7. A control device described in any one of claims 1 to 6, wherein the value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or less than the first gear ratio is larger the smaller the gear ratio.

8. A control device for a human-powered vehicle, a control unit that controls a transmission that changes a gear ratio, which is a ratio of a rotational speed of a wheel of the human-powered vehicle to a rotational speed of a crankshaft of the human-powered vehicle, the control unit controls the transmission to change the gear ratio in accordance with a value corresponding to a rotational speed of the crankshaft that is determined based on a vehicle speed detected by a vehicle speed sensor and the gear ratio; A control device wherein a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or less than a first gear ratio is different from a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is greater than the first gear ratio, and the value is larger as the gear ratio is smaller.

9. The control device according to claim 1 , wherein the control unit controls the transmission to reduce the speed ratio when a value corresponding to the rotational speed of the crankshaft decreases.

10. A control device as described in Claim 9, wherein the value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to reduce the gear ratio when the gear ratio is less than the first gear ratio is equal to the value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to reduce the gear ratio when the gear ratio is greater than the first gear ratio.

11. A control device for a human-powered vehicle, a control unit that controls a transmission that changes a gear ratio, which is a ratio of a rotational speed of a wheel of the human-powered vehicle to a rotational speed of a crankshaft of the human-powered vehicle, the control unit controls the transmission to change the gear ratio in accordance with a value corresponding to a rotational speed of the crankshaft that is determined based on a vehicle speed detected by a vehicle speed sensor and the gear ratio; a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is equal to or less than a first gear ratio is different from a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to increase the gear ratio when the gear ratio is greater than the first gear ratio, a control device wherein a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to reduce the gear ratio when the gear ratio is equal to or smaller than the first gear ratio is equal to a value corresponding to the rotational speed of the crankshaft when the control unit controls the transmission to reduce the gear ratio when the gear ratio is greater than the first gear ratio.

12. the control unit changes the gear ratio to a second gear ratio at least one of when the human-powered vehicle stops traveling and when the human-powered vehicle resumes traveling; The control device according to claim 1 , wherein the first speed change ratio is equal to or less than the second speed change ratio.

Images