Method and system for detecting bicycle speed

Abstract

A method for detecting the speed of a bicycle equipped with an ABS system on the front wheel, wherein the bicycle speed is identified as a rear wheel speed if the rear wheel deceleration is below a predetermined tolerance limit value, or the bicycle speed is identified as a front wheel speed if the front brake circuit pressure is below a predetermined low pressure tolerance limit, or the bicycle speed is an estimated speed based on the last known speed and an estimated deceleration.

Description

[Technical field]

[0001] The present disclosure relates to the field of electric bicycles, and more particularly to a method and system for detecting the speed of a bicycle equipped with an ABS system on the front wheel. In particular, the object of the present invention is a bicycle motion observer that is part of the control system used within the ABS system.

[0002] The purpose of this software-based component is to calculate the real-time bike speed, regardless of whether the individual measured wheel speeds are reliable (e.g. if any wheel is locked or skidding), thus allowing continuous control of the ABS system even in dangerous situations.

[0003] As is well known, when a rider brakes on a bicycle equipped with an ABS system, it is necessary to know whether the controlled wheel is locked or not, which can only be done by comparing the wheel speed at which the brakes are applied with the bicycle speed.

[0004] However, when one or both of the bicycle wheels are locked or slipping, a best estimate of bicycle speed from available data is required. For example, a bicycle equipped with an ABS system on the front wheel may have available data on front wheel speed (from a rotational speed sensor on the front wheel), rear wheel speed (from a rotational speed sensor on the rear wheel), and front brake circuit pressure (from a pressure transducer in the front brake hydraulic circuit).

[0005] Under normal conditions without brakes, it can be assumed that the rear wheel speed is the most reliable source of bicycle speed. However, if the bicycle is decelerating strongly, it must be taken into account that one or the other or both wheel speeds may be unreliable. If the bicycle is decelerating strongly but there is no pressure in the front brake circuit, it can be assumed that the rear brake is applied and there is also a risk of the rear wheel skidding or locking. Therefore, the front wheel speed should be considered as the most reliable source of bicycle speed data. Conversely, if the bicycle is decelerating and the front brake circuit is pressurized, there is a risk of the front wheel slipping or locking. Unfortunately, there is no way to measure the pressure in the rear brake circuit, so it cannot be assumed that the rear wheel speed is reliable.

[0006] It is therefore an object of the present invention to estimate the speed of a bicycle under these conditions in an effective, reliable and simple manner.

[0007] Such an object is achieved by a method for detecting a bicycle speed according to claim 1 and a system for detecting a bicycle speed according to claim 9. The dependent claims relate to preferred embodiments of the method and the system according to the invention.

[0008] According to a general embodiment of the invention, the method detects the speed of a bicycle equipped with an ABS system on the front wheel, the method comprising the steps of:

[0009] Obtaining the front wheel speed from a first rotational speed sensor on the front wheel;

[0010] Obtaining rear wheel speed from a second rotational speed sensor on the rear wheel;

[0011] obtaining front brake circuit pressure from a pressure transducer in the front brake hydraulic circuit; and

[0012] Calculate rear wheel deceleration.

[0013] If the rear wheel deceleration is below a predetermined acceptable limit, the bicycle speed is identified by the rear wheel speed.

[0014] If the rear wheel deceleration is higher than a predetermined acceptable limit, the method includes the further steps of:

[0015] If the front brake circuit pressure is below a predetermined low pressure tolerance limit, bicycle speed is identified by front wheel speed.

[0016] If the front brake circuit pressure is greater than a predetermined low pressure tolerance limit, the bicycle speed is an estimated speed calculated according to the following substeps:

[0017] Store the front wheel speed in a memory buffer;

[0018] Calculating a front wheel average speed and a front wheel deceleration when the memory buffer is filled;

[0019] if the value of the front wheel deceleration is within a predetermined deceleration tolerance limit, estimate the bicycle speed as the last calculated value of the front wheel average speed and store the values ​​of the front wheel average speed and the front wheel deceleration;

[0020] If the front wheel deceleration value exceeds a predetermined allowable deceleration limit, then the bicycle speed is estimated as the difference between the stored front wheel average speed value and the stored front wheel deceleration value multiplied by the time elapsed since the front wheel average speed and front wheel deceleration values ​​were stored.

[0021] According to one aspect of the invention, at least some of the method steps are performed by a finite state machine having a first state where the bicycle speed is a rear wheel speed, a second state where the bicycle speed is an estimated speed, and a third state where the bicycle speed is a front wheel speed.

[0022] a transition from the first state to the second state occurs when the front brake circuit pressure is greater than a high pressure tolerance limit and a difference between the front and rear wheel speeds is greater than a predetermined high delta wheel speed tolerance limit;

[0023] a transition from the second state to the third state occurs when the front brake circuit pressure is less than a predetermined low pressure tolerance limit;

[0024] a transition from the third state to the second state occurs when the front brake circuit pressure is greater than a predetermined high pressure tolerance limit;

[0025] a transition from said second state to said first state occurs when a difference between the estimated speed and the rear wheel speed is less than a predetermined low delta wheel speed tolerance limit;

[0026] a transition from the first state to the third state occurs when the front brake circuit pressure is less than a predetermined low pressure tolerance limit and a difference between the front and rear wheel speeds is greater than a predetermined high delta wheel speed tolerance limit;

[0027] A transition from the third state to the first state occurs when the difference between the front and rear wheel speeds is less than a predetermined low-delta wheel speed tolerance limit.

[0028] In one embodiment, the high pressure tolerance limit is the pressure tolerance limit above which the front wheels are deemed to be slipping or locking.

[0029] In one embodiment, the low pressure tolerance limit is the pressure tolerance limit below which the front wheels are considered to be rotating freely.

[0030] In one embodiment, the high delta wheel speed tolerance limit is the delta wheel speed tolerance limit above which a wheel is considered to be slipping.

[0031] In one embodiment, the low delta wheel speed tolerance limit is the delta wheel speed tolerance limit below which both wheels are considered to be rotating at the same speed.

[0032] According to a further aspect of the invention, a transition detection time interval is provided which is calculated if the detected bicycle speed changes from an old value corresponding to one of the front wheel speed, rear wheel speed and estimated speed to a different new value corresponding to a different one of the front wheel speed, rear wheel speed and estimated speed, during which the bicycle speed gradually changes from the old value to the new value.

[0033] In one embodiment, when the detected bicycle speed changes from the old value to the new value, the last detected value is stored and a transition speed value is calculated as follows: Transition speed value = new value - (saved value / (elapsed time) n ) where elapsed time: period since change from the old value; n<1.

[0034] A system for detecting the speed of a bicycle equipped with an ABS system on the front wheel is also disclosed. According to a general embodiment, the system includes:

[0035] A first rotational speed sensor suitable for detecting the front wheel speed;

[0036] A second rotational speed sensor suitable for detecting the rear wheel speed;

[0037] a pressure transducer suitable for sensing front brake circuit pressure in the front brake hydraulic circuit; and

[0038] An electronic control unit operatively coupled to the first rotational speed sensor, the second rotational speed sensor, and the pressure transducer.

[0039] The electronic control unit is configured to perform the method for detecting bicycle speed disclosed above.

[0040] According to one aspect of the invention, the electronic control unit includes a speed estimator module operatively coupled to the first rotational speed sensor and a memory buffer and configured to estimate the bicycle speed according to the following instructions:

[0041] storing the front wheel speed in said memory buffer;

[0042] calculating a front wheel average speed and a front wheel deceleration when the memory buffer is filled;

[0043] if the front wheel deceleration value is within a predetermined allowable deceleration limit, estimating the bicycle speed as the last calculated front wheel average speed value;

[0044] storing said front wheel average speed and front wheel deceleration values ​​in said memory buffer;

[0045] and when the front wheel deceleration value exceeds a predetermined allowable deceleration limit, estimating bicycle speed as the difference between the stored front wheel average speed value and the stored front wheel deceleration value multiplied by the elapsed time since the front wheel average speed and front wheel deceleration values ​​were stored.

[0046] According to one embodiment, the electronic control unit includes a speed selection state machine module operatively coupled to the first rotational speed sensor, the second rotational speed sensor, the pressure transducer, and the speed estimator module, the speed selection state machine module configured to execute the speed selection state machine disclosed above.

[0047] According to one embodiment, the electronic control unit further includes a speed selection switch module operatively coupled to the first rotational speed sensor, the second rotational speed sensor, and the speed estimator module, the speed selection switch module configured to selectively output one of the output data from the first rotational speed sensor, the second rotational speed sensor, and the speed estimator module according to a control signal received from the speed selection state machine module.

[0048] According to one aspect of the invention, the electronic control unit further includes a discontinuity correction module configured to store a last detected speed value and calculate a transition speed value when the detected bicycle speed changes from an old value corresponding to one of the front wheel speed, rear wheel speed, and estimated speed to a different new value corresponding to a different one of the front wheel speed, rear wheel speed, and estimated speed as follows: Transition speed value = new value - (saved value / (elapsed time) n ) where elapsed time: period since change from the old value; n<1.

[0049] The above brief summary of exemplary embodiments is helpful in understanding the basics of the present disclosure. This summary is not an extensive summary of all contemplated embodiments, and is not intended to identify key or critical elements of all embodiments of the present disclosure or to delineate the scope of any or all embodiments thereof. Its sole purpose is to present one or more embodiments in a simplified form as a prelude to the more detailed description of the disclosure that follows. To this end, one or more embodiments of the present disclosure include the features recited and exemplified in the claims. [Brief description of the drawings]

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more exemplary aspects of the disclosure and, together with the detailed description, serve to explain the principles and operation thereof.

[0051] FIG. 1 is a flow chart of a method for detecting bicycle speed according to a general embodiment of the present invention.

[0052] FIG. 2 is a diagram showing a system for detecting bicycle speed.

[0053] FIG. 3 is a speed versus time diagram illustrating the behavior of the speed estimator module when the front wheel deceleration remains within predetermined acceptable limits.

[0054] FIG. 4 is a speed versus time diagram illustrating the behavior of the speed estimator module when the front wheel deceleration suddenly exceeds a predetermined tolerance limit.

[0055] FIG. 5 is a table illustrating the logical conditions that must be satisfied to enable each state transition in a finite state machine according to the present invention.

[0056] FIG. 6 is a time versus speed diagram illustrating the behavior of the discontinuity correction module.

[0057] A detailed description of the preferred embodiments of the present invention is disclosed below with reference to the above-mentioned accompanying drawings.

[0058] Exemplary embodiments are described herein in the context of a system and method for detecting the speed of a bicycle equipped with an ABS system. Those skilled in the art will appreciate that the following description is merely illustrative and is not intended to be limiting in any sense. Other embodiments will be readily apparent to those skilled in the art having the benefit of this disclosure. Reference will now be made in detail to implementations of the exemplary embodiments, which are illustrated in the accompanying drawings.

[0059] FIG. 1 discloses a general embodiment of a method for detecting bicycle speed.

[0060] The method may be performed by a real-time computational model that estimates bicycle speed using the following as input data:

[0061] Oil pressure data measured in front brake caliper circuit10;

[0062] Front wheel speed data20; and

[0063] Rear wheel speed data30.

[0064] The pressure data may be obtained from a pressure transducer 12 in the front brake hydraulic circuit.

[0065] The front wheel speed data 20 may be obtained from a first rotational speed sensor 22 on the front wheel.

[0066] Rear wheel speed data 30 may be obtained from a second rotational speed sensor 32 on the rear wheel.

[0067] As a starting point 100, the bicycle speed corresponds to the rear wheel speed.

[0068] In step 102, the rear wheel deceleration is calculated.

[0069] In step 104, the rear wheel deceleration is compared to a predetermined acceptable limit.

[0070] If the rear wheel deceleration is below a predetermined acceptable limit, the bicycle speed is identified by the rear wheel speed.

[0071] If the rear wheel deceleration is greater than a predetermined acceptable limit, step 106 checks whether there is pressure in the front brake circuit.

[0072] If the front brake circuit pressure is below the predetermined low pressure tolerance limit, the bicycle speed is identified by the front wheel speed (step 108).

[0073] If the front brake circuit pressure is greater than the predetermined low pressure tolerance limit, the bicycle speed is an estimated speed calculated as described below with reference to FIG. 2 (step 110).

[0074] FIG. 2 discloses a block diagram of a system 200 for detecting bicycle speed, according to an exemplary embodiment of the invention.

[0075] The system 200 includes a first rotational speed sensor 22 suitable for detecting a front wheel speed, a second rotational speed sensor 32 suitable for detecting a rear wheel speed, a pressure transducer 12 suitable for detecting a front brake circuit pressure in a front brake hydraulic circuit, and an electronic control unit 40 operatively coupled to the first rotational speed sensor 22, the second rotational speed sensor 32 and the pressure transducer 12.

[0076] The electronic control unit 40 disclosed in FIG. 2 includes low pass filters 42 and 44 , a speed estimator module 46 , a speed selection state machine module 48 , a speed selection switch 50 , and an outage correction module 52 .

[0077] These components of electronic control unit 40 will now be described in detail.

[0078] The low pass filters 42 and 44 are calculation blocks that filter the raw speed data to avoid spikes on the signal that can cause calculation errors. These functions are designed to keep the delay time as short as possible so as not to impair the responsiveness of the ABS control system. There are several filter techniques available that can be used for this purpose. For example, a moving average filter can be implemented.

[0079] The speed estimator module 46 consists of a calculation block that estimates the bicycle speed. In some examples, it is constantly performing its calculations even when the speed estimator results are not being diverted to the ABS control system via the speed select switch module 50.

[0080] The calculation takes as its input the measured front wheel speed measurements and loads the speed data points into a memory buffer. When the memory buffer is filled, the algorithm calculates the average of all the values ​​(wheel average speed) and also calculates the difference between the highest and lowest value in the buffer (which, when divided by the time it takes to fill the buffer, gives the wheel deceleration).

[0081] If the deceleration value is within certain acceptable limits, the speed estimator module outputs the last calculated wheel average speed value, and the wheel average speed and deceleration values ​​are stored in memory.

[0082] When the deceleration value exceeds the tolerance limit, the output of the module is equal to the previously stored wheel average speed value minus the previously stored wheel deceleration value multiplied by the time elapsed since those values ​​were stored.

[0083] Therefore, the behavior of the speed estimator module can be summarized as follows:

[0084] If the wheel deceleration is within a predefined limit, it can be assumed that the wheels are not locked or skidding. The output of the module is equal to the average wheel speed. This is illustrated in Figure 3.

[0085] If the wheel deceleration exceeds a predefined tolerance limit, the wheel can be assumed to have experienced a sudden change in speed due to locking or skidding. The output of the module is calculated assuming that the bicycle continues to decelerate at the same rate as before the locking or skidding occurred. This is illustrated in Figure 4.

[0086] The state machine module 48 implements a decision process that is used to select between available bike speed sources based on the following input data:

[0087] Filtered front wheel speed;

[0088] Filtered rear wheel speed;

[0089] Estimated speed;

[0090] Front brake pressure; and

[0091] Reference constants

[0092] The rate selection state machine has three states:

[0093] State 1: Rear Wheel Speed ​​Selected The output of the speed select state machine module 48 indicates to the speed select switch module 50 that a rear wheel speed should be selected.

[0094] State 2: Estimated Speed ​​is Selected The output of the speed select state machine module 48 indicates to the speed select switch module 50 that estimated speed should be selected.

[0095] State 3: Front Wheel Speed ​​Selected The output of the speed select state machine module 48 indicates to the speed select switch module 50 that the front wheel speed should be selected.

[0096] The logical flow between these states is controlled by a series of transitions, indicated by numbered arrows in Figure 2. The transitions occur when each logical state becomes actual.

[0097] For this purpose, during the calibration stage of ABS system development, a list of fixed parameter values ​​must be programmed into the system. These parameters are:

[0098] High caliper pressure limit: The pressure limit above which there is a risk of the front wheels slipping or locking.

[0099] Low Caliper Pressure Limit: The pressure limit below which the front wheels are considered to be rotating freely.

[0100] High Delta Wheel Speed ​​Limit: The allowable delta wheel speed limit above which one wheel is considered to be slipping.

[0101] Low Delta Wheel Speed ​​Limit: The allowable delta wheel speed limit below which both wheels are considered to be rotating at the same speed.

[0102] The logical conditions that must be met for each transition to occur are as follows (see the annotations in Figure 2 for transition numbers): These logical conditions are explained in the table in Figure 5.

[0103] a transition (1) from the first condition to the second condition occurs when the front brake circuit pressure is greater than the high caliper pressure allowable limit and the difference between the front and rear wheel speeds is greater than the high delta wheel speed allowable limit;

[0104] a transition (2) from the second condition to the third condition occurs when the front brake circuit pressure is lower than the allowable low caliper pressure limit;

[0105] a transition (3) from the third condition to the second condition occurs when the front brake circuit pressure is greater than the high caliper pressure allowable limit;

[0106] a transition (4) from the second state to the first state occurs when a difference between the estimated speed and the rear wheel speed is less than the allowable limit for the low delta wheel speed;

[0107] a transition (5) from the first condition to the third condition occurs when the front brake circuit pressure is less than the allowable limit for the low caliper pressure and the difference between the front and rear wheel speeds is greater than the allowable limit for the high delta wheel speed;

[0108] A transition (6) from the third state to the first state occurs when the difference between the front and rear wheel speeds is less than the allowable limit of the low delta wheel speed.

[0109] The speed select switch module 50 is operatively connected from its input to the output of the rear wheel speed data low pass filter 44, to the output of the front wheel speed data low pass filter 42, and to the output of the speed estimator module 46. The speed select switch module 50 has a control input for receiving a switch select request signal from a speed select state machine module 48.

[0110] Depending on the output from the state machine module 48 , the correct speed value is passed to the output of the bicycle motion observer system 200 .

[0111] The outage correction module 52 is operatively connected to the output of the speed select switch module 50 and to the output of the speed select state machine 48. Thus, the switch select request signal is also received by the outage correction module 52.

[0112] The function of the discontinuity correction module 52 is to avoid abrupt discontinuities in the speed values ​​when the speed selection switch is changed between input sources.

[0113] When the discontinuity detection module 52 detects that the value of the switch select request from the state machine has changed, the last detected value from the speed select switch module is saved to memory.

[0114] In subsequent calculation steps, the following output values ​​are calculated: Output value = new speed data – (saved data / (elapsed time) n ) Wherein, elapsed time: the period since the switch selection request changed; n<1.

[0115] The behavior of the module is such that if a discontinuity occurs between the selected data sources, the output data is smoothed after the switch occurs and tends to the value from the new data source. The rate at which the trend to the new data source occurs depends on the value of the power n. The behavior of the discontinuity correction block is illustrated in Figure 6.

[0116] As can be seen from the above description, said estimated speed is calculated mathematically without the use of inertial sensors. If both wheel speeds are unreliable (e.g., it is not known whether the rear wheel speeds are reliable and the front wheels may also be skidding because pressure beyond some reference value has been applied to the front brake calipers), the estimated speed is used.

[0117] Advantageously, it is possible to estimate the bicycle speed without the use of inertial sensors, with the final calculated speed being the most reliable derived from the input data listed above.

[0118] The proposed computational method potentially requires low computational power and the entire algorithm can be run in the background while still providing accurate and reliable results.

[0119] It should be noted that the term "module" as used in this disclosure refers to a real-world device, component, or arrangement of components implemented using hardware, such as, for example, an application specific integrated circuit (ASIC) or FPGA, or as a combination of hardware and software, such as a microprocessor system and a set of instructions for performing the functions of the module that (during execution) transform the microprocessor system into a dedicated device. A module may also be implemented as a combination of the two, where some functions are facilitated solely by hardware and other functions are facilitated by a combination of hardware and software. In a particular implementation, at least a portion, and possibly all, of the modules may be executed on a processor of a computer system. Thus, each module may be realized in a variety of suitable configurations and should not be limited to the particular implementation exemplified herein.

[0120] The various aspects disclosed herein encompass present and future known equivalents of the known modules referenced herein by way of example. Moreover, while aspects and applications have been illustrated and described, it will be apparent to one of ordinary skill in the art having the benefit of this disclosure that many more modifications than those described above are possible without departing from the inventive concepts disclosed herein.

[0121] For example, although disclosed herein with respect to bicycles, it will be apparent that the concepts of the present invention can be extended to other types of vehicles, such as other two-wheeled vehicles (e.g., scooters and motorcycles) with ABS on the front wheel only, or other vehicles in which ABS is applied to the brakes on a single axle via a single hydraulic circuit and the average speed of the wheels on another axle is also used as input data to the system.

[0122] Further, for clarity, this disclosure has referred to a bicycle having an ABS system on the front wheel, however, as would be apparent to one of ordinary skill in the art having the benefit of this disclosure, the concepts of the present invention may also be applied to bicycles or other vehicles having an ABS system mounted on the rear wheel.

Claims

1. A method for detecting the speed of a bicycle equipped with an ABS system on the front wheel, a) Obtain the front wheel speed from the first rotational speed sensor on the front wheel; b) Obtain the rear wheel speed from the second rotational speed sensor on the rear wheel; c) Obtain the front brake circuit pressure from the pressure transducer in the front brake hydraulic circuit; and d) Calculate the rear wheel deceleration; e) If the rear wheel deceleration is lower than a predetermined permissible limit, the bicycle speed is determined by the rear wheel speed; otherwise f) If the front brake circuit pressure is lower than a predetermined low-pressure tolerance limit, the bicycle speed is determined by the front wheel speed, otherwise g) Bicycle speed is as follows: i) Store the front wheel speed in a memory buffer; ii) When the memory buffer is full, calculate the average front wheel speed and the front wheel deceleration; iii) If the value of the front wheel deceleration is within a predetermined deceleration tolerance limit, the bicycle speed is estimated as the value of the last calculated front wheel average speed, and the values ​​of the front wheel average speed and front wheel deceleration are stored; iv) If the front wheel deceleration value exceeds a predetermined deceleration tolerance limit, the bicycle speed is estimated as the difference between the saved average front wheel speed and the saved front wheel deceleration value obtained by multiplying the average front wheel speed and the front wheel deceleration value by the elapsed time since the value was saved in substep iii). This is the estimated speed calculated according to the substeps. A method including steps.

2. Steps d), e), f), and g) are performed by a finite state machine having a first state where the bicycle speed is the rear wheel speed, a second state where the bicycle speed is the estimated speed, and a third state where the bicycle speed is the front wheel speed. - When the front brake circuit pressure is higher than the high-pressure tolerance limit, and the difference between the front wheel speed and the rear wheel speed is greater than the predetermined high-delta wheel speed tolerance limit, the transition from the first state to the second state occurs; - When the front brake circuit pressure is lower than a predetermined low-pressure tolerance limit, the transition from the second state to the third state occurs; - When the front brake circuit pressure is higher than a predetermined high-pressure tolerance limit, the transition from the third state to the second state occurs; - When the difference between the estimated speed and the rear wheel speed is smaller than a predetermined allowable limit for low delta wheel speed, the transition from the second state to the first state occurs; - When the front brake circuit pressure is lower than a predetermined low-pressure tolerance limit, and the difference between the front wheel speed and the rear wheel speed is greater than a predetermined high-delta wheel speed tolerance limit, the transition from the first state to the third state occurs; - The transition from the third state to the first state occurs when the difference between the front wheel speed and the rear wheel speed is smaller than a predetermined allowable limit for low delta wheel speed. The method according to claim 1.

3. The method according to claim 2, wherein the high-pressure tolerance limit is a pressure tolerance limit value that, if exceeded, is considered to cause the front wheels to slip or lock.

4. The method according to claim 2 or 3, wherein the low pressure tolerance limit is a pressure tolerance limit value below which the front wheels are considered to be rotating freely.

5. The method according to any one of claims 2 to 4, wherein the permissible limit for the high delta wheel speed is the permissible limit value of the delta wheel speed above which one wheel is considered to be slipping.

6. The method according to any one of claims 2 to 5, wherein the permissible limit for the low delta wheel speed is a permissible limit value for delta wheel speed below which both wheels are considered to be rotating at the same speed.

7. The method according to any claim, wherein a transition detection time interval is provided during which the bicycle speed is gradually changed from an old value corresponding to one of the front wheel speed, rear wheel speed, and estimated speed to a different new value corresponding to a different one of the front wheel speed, rear wheel speed, and estimated speed.

8. When the detected bicycle speed changes from the old value to the new value, the last detected value is saved, and the transition speed value is, Transition rate value = New value - (Saved value / (Elapsed time)) ｎ ) (In the formula, elapsed time: the period since the change from the previous value; n < 1) The method according to claim 7, which is calculated as follows.

9. A system for detecting the speed of a bicycle equipped with an ABS system on the front wheel, - A first rotational speed sensor suitable for detecting front wheel speed; - A second rotational speed sensor suitable for detecting rear wheel speed; - A pressure transducer suitable for detecting front brake circuit pressure within the front brake hydraulic circuit; and - An electronic control unit operably coupled to the first rotational speed sensor, the second rotational speed sensor, and the pressure transducer, configured to perform the method for detecting the bicycle speed according to any of the claims. A system that includes this.

10. The electronic control unit is operably coupled to the first rotational speed sensor and the memory buffer. The front wheel speed is stored in the memory buffer; When the memory buffer is full, the average front wheel speed and front wheel deceleration are calculated; If the value of the front wheel deceleration is within the predetermined deceleration tolerance limit, the bicycle speed is estimated as the value of the last calculated front wheel average speed. The values ​​of the average front wheel speed and the front wheel deceleration are stored in the memory buffer; If the front wheel deceleration value exceeds a predetermined deceleration tolerance limit, the bicycle speed is estimated as the difference between the saved average front wheel speed and the saved front wheel deceleration value, which is obtained by multiplying the average front wheel speed by the elapsed time since the front wheel deceleration value was saved. The system according to claim 9, comprising a speed estimator module configured as follows.

11. The system according to claim 10, wherein the electronic control unit is operably coupled to the first rotational speed sensor, the second rotational speed sensor, a pressure transducer, and a speed estimator module, and includes a speed selection state machine module configured to perform a speed selection state machine according to any one of claims 2 to 6.

12. The system according to claim 11, wherein the electronic control unit further comprises a speed selection switch module operably coupled to the first rotational speed sensor, the second rotational speed sensor, and the speed estimator module, and configured to selectively output one of the output data from the first rotational speed sensor, the second rotational speed sensor, and the speed estimator module in accordance with a control signal received from the speed selection state machine module.

13. When the detected bicycle speed changes from an older value corresponding to one of the front wheel speed, rear wheel speed, and estimated speed to a different new value corresponding to one of the front wheel speed, rear wheel speed, and estimated speed, the electronic control unit saves the last detected speed value and the transition speed value Transition rate value = New value - (Saved value / (Elapsed time)) ｎ ) (In the formula, elapsed time: the period since the change from the previous value; n < 1) The system according to any one of claims 9 to 12, further comprising a discontinuity correction module configured to calculate as follows.

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