Description:FIELD OF THE INVENTION
Embodiments of the present invention generally relates to electromotive technology. More particularly the invention relates to an electric bicycle adaptive pedal assist system using a cadence sensor assembly.
BACKGROUND OF THE INVENTION
Cadence measurement plays a crucial role in the operation of electric bicycles, as it enables seamless integration of human pedaling power with electrical motor assistance. The cadence, or pedaling rate, directly influences the responsiveness and efficiency of the electric bicycle's motor assembly.
In traditional electric bicycle designs, the motor assistance is often provided as a predefined percentage based on a selected pedal assist mode, irrespective of the rider's actual cadence or pedaling rate. This approach fails to account for the dynamic nature of human pedaling, resulting in inefficiencies and potential mismatches between the rider's efforts and the motor's output.
Furthermore, conventional cadence sensor assemblies or systems are often plagued by design complexities, leading to increased latency in detecting pedal movements and inaccuracies in motor assistance. These limitations can negatively impact the overall riding experience, energy efficiency, and assembly responsiveness.
Therefore, there is a need for an improved cadence sensor assembly that addresses these shortcomings and provides a more intuitive and efficient integration of human power with electrical assistance. Such an assembly should prioritize simplicity in design, minimize latency, and adapt the motor assistance dynamically based on the rider's real-time cadence. By achieving these objectives, the invention can enhance the overall riding experience, improve energy efficiency, and promote a seamless collaboration between the rider and the electric bicycle's motor assembly.

OBJECT OF THE INVENTION
An object of the present invention is to provide a compact and lightweight cadence sensor assembly for electric bicycles by achieving optimal performance with minimal complexity by prioritizing simplicity in the design and reducing unnecessary components.
Another object of the present invention is to minimize latency in data acquisition and improve responsiveness through fine-tuning of signal processing algorithms and optimization of the processing module and Hall sensor configuration.
Yet another object of the present invention is to enhance energy efficiency by precisely measuring the rider's cadence (RPM), segmenting it into ranges, and calibrating the exact amount of motor assistance required for each RPM range.
Yet another object of the present invention is to provide adaptive motor assistance based on the rider's real-time cadence, instead of a predefined assistance level based solely on the pedal assist mode, thereby improving the overall riding experience.
Yet another object of the present invention is to enhance manufacturing efficiency and reduce production costs by minimizing the number of components and streamlining assembly requirements.
Yet another object of the present invention is to improve the reliability and durability of the cadence sensor assembly through simplification of the design and reduction of complexity.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simple manner, which is further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the subject matter nor to determine the scope of the invention.
According to first aspect of the present invention, there is provided a cadence sensor assembly for an electric bicycle having a pedal assembly with one or more pedals coupled to corresponding pedal shaft, a gearbox housing proximal to the pedal shaft, at least one wheel, and an electric motor configured to drive the at least one wheel, the pedal shaft configured to rotate in response to the pedaling motion of the rider on the one or more pedals. The cadence sensor assembly comprises a magnet disc, a cadence printed circuit board or cadence PCB with atleast one Hall sensor, and a processing module. The magnet disc coupled to pedal shaft. The cadence printed circuit board or cadence PCB with a pair of Hall sensors mounted in the gearbox housing; wherein the at least one Hall sensor is positioned proximate to the magnet disc. The processing module is configured to: receive a frequency signal corresponding to the rotation speed of the magnet disc from at least one Hall sensor; calibrate the cadence sensor assembly by mapping the frequency signal (based on the rider’s rpm) to predetermined cadence revolutions per minute or RPM to establish a calibration curve; determine a cadence RPM range based on the calibrated frequency signal and the established calibration curve; determine a motor revolution per minute or motor RPM, based on the determined cadence RPM range and a selected pedal assist mode; wherein the motor assistance level is dynamically adjusted in real-time based on changes in the determined cadence RPM range during pedaling; and trigger one or more switches that supply power to the electric motor to provide the determined motor RPM or motor assistance to the at least one wheel by adjusting a supply of power to the electric motor based on the selected pedal assistance level by the rider.
In accordance with an embodiment of the present invention, the processing module is further configured to calibrate the cadence sensor assembly by, rotating the pedal shaft at a predetermined cadence revolutions per minute or RPM. The predetermined cadence revolutions per minute or RPM ranges from 2 to 110 revolutions per minute; measure the frequency signal from at least one Hall sensor during the rotation of the pedal shaft at the predetermined cadence RPM; map the measured frequency signal to the predetermined cadence RPM to establish a calibration curve; and store the calibration curve for determining cadence RPM ranges based on received frequency signals during operation.
In accordance with an embodiment of the present invention, the magnet disc, which consists of magnets pressed within the disc of different polarity is secured within a groove of the pedal shaft by magnetic attraction of the magnet disc.
In accordance with an embodiment of the present invention, the processing module is further configured to calculate the amount of current required for the electric motor to provide the determined motor assistance level.
In accordance with an embodiment of the present invention, the assembly further includes a gate driver coupled to the processing module and configured to trigger one or more switches selected from power transistors, SCR, MOSFET, IGBT or a combination thereof.
In accordance with an embodiment of the present invention, the assembly further includes a noise filter configured to remove electromagnetic interference from the frequency signal received from the at least one Hall sensor.
In accordance with an embodiment of the present invention, the pedal assist mode selector or a user interface is configured to allow the rider to select the pedal assist mode.
In accordance with an embodiment of the present invention, the pedal assist mode selected from Eco mode, Normal mode, Tour mode, Power mode and boost mode, wherein the processing module determines the motor assistance level based on the detected cadence RPM range and the selected pedal assist mode
In accordance with an embodiment of the present invention, the motor assistance level determined by the processing module comprises a level of power or torque output provided by the electric motor to assist the rider's pedaling effort based on the detected cadence RPM and the selected pedal assist mode.

BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above-recited features of the present invention can be understood in detail, a more particular to the description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, the invention may admit to other equally effective embodiments.
These and other features, benefits and advantages of the present invention will become apparent by reference to the following text figures, with like reference numbers referring to like structures across the views, wherein:
Fig. 1 illustrates a cadence sensor assembly for an electric bicycle, in accordance with an embodiment of the present invention;
Fig. 2 illustrates a magnetic disc and pedal shaft arrangement in the cadence sensor assembly, in accordance with an embodiment of the present invention;
Fig. 3 illustrates a magnetic disc and cadence PCB arrangement in the cadence sensor assembly, in accordance with an embodiment of the present invention;
Fig. 4A-4B illustrates a cadence PCB and gearbox housing arrangement in the cadence sensor assembly, in accordance with an embodiment of the present invention; and
Fig. 5 illustrates a block diagram for cadence sensor assembly for an electric bicycle, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and is not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It is implied that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims.
As used throughout this description, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense, (i.e., meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all these matters form a part of the prior art base or were common general knowledge in the field relevant to the present invention.
The present invention is described hereinafter by various embodiments with reference to the accompanying drawings, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
Figure 1 illustrates a cadence sensor assembly for an electric bicycle, in accordance with an embodiment of the present invention. As shown in figure 1, the cadence sensor assembly (100) may be installed in an electric bicycle within the mid-drive motor. The bicycle may be retrofitted or consists of an electric mid-motor or any motor assembly. It may enclose a pedal shaft (106). The pedal shaft (106) may be coupled to a magnet disc (104). The magnet disc (104) may include a plurality of magnets (108) arranged in alternating polarity. The cadence sensor assembly (100) may further include a cadence printed circuit board or cadence PCB (102) mounted within the gearbox housing (111). The cadence PCB (102) may include a Hall-effect sensor (110), positioned proximate to the magnet disc (104).
The electric bike referred here may be selected from, but not limited to, an electric, a hybrid with both electrical and a fuel hybrid bike, a paddle and electric hybrid bicycle, an electric moped, and like. The assembly (100) may be fitted proximal to the gearbox. In a preferred embodiment, the assembly (100) is fitted inside the gearbox.
Figure 2 illustrates a magnetic disc and pedal shaft arrangement in the cadence sensor assembly, in accordance with an embodiment of the present invention. As shown in figure 2, the pedal shaft (106) may be an elongated cylindrical component. It may connect to the pedals and crank arms and rotates in response to the rider's pedaling motion. The pedal shaft (106) may be made of a durable and corrosion-resistant material to withstand prolonged use and exposure to various environmental conditions. The choice of materials for both the pedal shaft (106) and the magnetic disc (104) depends on factors such as durability, weight, cost, and performance requirements. The materials mentioned may vary based on specific configuration considerations and manufacturing processes.
The materials for the pedal shaft (106) may be selected from, but not limited to, stainless steel, magnesium chromium alloy steel, chromium-molybdenum alloy steel, titanium alloy, carbon fibre reinforced polymer (CFRP), aluminium alloy, nickel-chromium alloy, cobalt-chromium alloy, magnesium alloy, beryllium-copper alloy, or high-strength plastic composites or a combination thereof. The magnets (108), is typically made from a material that may be magnetized and retain its magnetic properties over an extended period. The materials for the magnet (108) may be selected from, but not limited to, neodymium-iron-boron (NdFeB) magnets, samarium-cobalt (SmCo) magnets, alnico magnets, ferrite magnets, bonded rare-earth magnets, ceramic magnets, plastic bonded magnets, rubber bonded magnets, magnetic composites, or electromagnetic coils or combination thereof. The materials for the magnet disc may be selected from, but not limited to, Nylon or abs, or, any other plastic compositions, or acrylic material, or other plastic compositions or insulation materials. The magnetic disc (104) may be a circular disc pressed with small magnets coupled to the pedal shaft (106). It may have a plurality of magnets arranged in alternating polarity around its circumference. The alternating polarity may be understood as N-S-N-S-N-…. configuration or S-N-S-N-S… configuration. The arrangement may allow the magnetic disc (104) to rotate synchronously with the pedal shaft (106) when the rider pedals.
Figure 3 illustrates a magnetic disc (104) and cadence PCB (102) arrangement in the cadence sensor assembly (100), in accordance with an embodiment of the present invention. As the magnets on the rotating disc (104) may pass by the Hall-effect sensor (1024), it detects the changing magnetic field and generates a frequency signal proportional to the rotation speed or cadence RPM of the pedal shaft (106). The cadence PCB (102) or cadence Printed Circuit Board (102) is a vital component of the cadence sensor assembly. It may include one or more electronic components responsible for detecting and processing the pedaling motion and cadence information.
Figures 4A-4B illustrate a cadence PCB (102) and gearbox housing arrangement (111) in the cadence sensor assembly, in accordance with an embodiment of the present invention. The cadence PCB or cadence Printed Circuit Board (102) may be mounted within the gearbox housing or in close proximity to the magnet disc (104) and), pedal shaft (106). It may include a proper wire routing (109) and a processing module or a controller (not shown in this figure). The cadence PCB (102) comprises several key components. The one or more Hall-effect sensors (1024) may be strategically positioned near the magnet disc (104) to detect the changing magnetic field as the magnets rotate which also senses the direction of rotation to resist the assistance during the reverse pedal. It may generate a frequency signal proportional to the rotation speed or cadence RPM of the pedal shaft (106). To ensure accurate signal processing, the cadence PCB (102) may incorporate a signal conditioning circuit that performs tasks such as amplification, filtering, and noise removal, resulting in a clean and reliable signal.
Figure 5 illustrates a block diagram for the cadence sensor assembly for an electric bicycle, in accordance with an embodiment of the present invention. As shown in figure 5, the signal from the cadence PCB (102) may be transferred to the processing module or microcontroller (208) responsible for performing one or more tasks related to motor assistance control.
The processing module (208) may be envisaged to include computing capabilities such as a memory unit configured to store machine-readable instructions. The machine-readable instructions may be loaded into the memory unit from a non-transitory machine-readable medium, such as, but not limited to, CD-ROMs, DVD-ROMs, and Flash Drives. Alternately, the machine-readable instructions may be loaded in the form of a computer software program into the memory unit. The memory unit in that manner may be selected from a group comprising EPROM, EEPROM, and Flash memory. Then, the processing module (208) includes a processor operably connected to the memory unit. In various embodiments, the processor may be a microprocessor selected from one of, but not limited to an ARM-based, DSP, Atmel, St- microcontrollers, or Intel-based processor, or in the form of field-programmable gate array (FPGA), a general-purpose processor and an application specific integrated circuit (ASIC).
The processing module (208) may receive the conditioned frequency signal from the Hall-effect sensor (1024) and may perform calibration by mapping the frequency signal to pre-segmented cadence RPM values, establishing a calibration curve to account for non-linearities or variations in the sensor response. Based on the calibrated frequency signal and the established calibration curve, the processing module (208) determines the cadence RPM range corresponding to the rider's pedaling rate. Then it may evaluate this cadence RPM range along with the selected pedal assist mode (e.g., Eco, Normal, Tour, Power, or Boost) to determine the appropriate motor assistance level required. The processing module (208) calculates the precise amount of motor assistance tailored to the rider's real-time cadence requirements within the determined RPM range and controls the electric motor accordingly. To ensure stable and reliable operation, the cadence PCB (102) may incorporate a power supply (not shown) and one or more power conditioning components (not shown), such as voltage regulators, one or more protection devices, one or more filters or combination thereof. The one or more protection devices may include, but are not limited to, a Zener diode, snubber circuit, Zener Diode, Transient Voltage Suppression (TVS) Diode, Polymeric Positive Temperature Coefficient (PPTC) Devices, Electromagnetic Interference (EMI) Filters, Metal-Oxide Varistors (MOVs) or a combination thereof.
The cadence PCB (102) may include wired (e.g., serial, I2C, SPI) communication interfaces to facilitate communication with other components of the electric bicycle system, such as the motor controller, processing module, user interface (not shown here), or diagnostic tools.
In some embodiments, the cadence PCB (102) may also include wireless (e.g., Bluetooth, Wi-Fi) communication interfaces (not shown) to facilitate communication with other components of the electric bicycle system, such as the motor controller, user interface, or diagnostic tools. Additionally, the PCB may feature LEDs for status indication, connectors for external connections, or additional sensors (e.g., temperature, vibration) for advanced monitoring and diagnostics. The compact configuration of the cadence PCB (102) within the cadence sensor assembly contributes to the overall efficiency and performance of the electric bicycle system.
In accordance with an additional or alternative embodiment of the present invention, as shown in Figure 5, the assembly (100) may comprise a user interface (212) may include or connected with one or more components selected from, but not limited to, push buttons, a kill switch, switches like PAS switches (202), toggle switches, a display or combination thereof. The display may be selected from, but not limited to, LED, LCD, or touch-enabled display. The user interface (212) or PAS switches (202), may be configured to input one or more instructions to the processing module (208) such as, but not limited to, initiating the calibration process, pedal assist mode, or emergency shutting the electric motor off. The kill switch connects the press switch and power supply. The kill switch (118), on actuation, is configured to form an open circuit in the power supply circuitry thereby electrically disengaging the connected motor from the electrical power.
To understand the workings of the invention, let's consider an electrical bike with a brushless DC motor or Permanent Magnet Synchronous Motors or PMSMs (214) equipped with the cadence sensor assembly installed proximal to the gearbox referring to figure 5 and figure 1.
Here the 750-watt brushless DC motor or Permanent Magnet Synchronous Motors or PMSMs (214) is referred to as a Mid-drive electric motor or any other motor (214). The motor (214) power may range from 250 to 1500 watt.
The electric bicycle has a shaft housing enclosing the pedal shaft (106) . The pedal shaft (106) is coupled with a magnet disc (104). The magnet disc (104) includes a plurality of magnets arranged in alternating polarity (e.g., N-S-N-S). The cadence sensor assembly (100) further includes a cadence-printed circuit board or PCB (102) mounted within the gearbox housing (111). The cadence PCB (102) comprises a cadence sensor (110), which is a Hall-effect sensor (1024), positioned proximate to the magnet disc (104) to detect the changing magnetic field as the magnets pass by.
When the rider starts pedaling, the pedal shaft (106) rotates, causing the magnet disc (104) to rotate synchronously. As the magnets on the rotating disc (104) pass by the Hall-effect sensor (1024), it detects the changing magnetic field and generates a frequency signal proportional to the rotation speed or cadence RPM of the pedal shaft (106).
In some embodiments, the cadence sensor assembly (100) may include more than one hall effect sensors (1024). It may be configured to detect the rotational direction of the pedal shaft which is coupled with the magnet disc (104), and this helps to restrict the motor assistance during anticlockwise rotation (reverse) of the pedal shaft (106). The cadence sensor assembly (100) also includes a processing module (208) that receives the frequency signal from the Hall-effect sensor (1024). The processing module (208) calibrates the frequency signal by mapping it to known cadence RPM values, thereby establishing a calibration curve. This calibration process accounts for any non-linearities or variations in the sensor response, ensuring accurate cadence measurement. The calibration process for the cadence sensor assembly can be initiated after installation or upon user selection through the user interface (212) or display.
During the calibration process, the rear wheel (not shown) of the electric bicycle needs to be rotated at specific predetermined cadence RPM values, either manually by the rider or using an external motor (not shown) or calibration mechanism. For example, the calibration process may require measurements at 50 RPM, 70 RPM, 90 RPM, and 110 RPM. The rider or the calibration mechanism rotates the rear wheel and pedal shaft (106) at these predetermined RPM values. The processing module (208) measures the frequency signal from the Hall-effect sensor (1024) at each RPM value and maps it to the known cadence RPM, establishing a calibration curve. This calibration curve is preprogrammed and stored in the assembly's memory for determining cadence RPM ranges based on the frequency signals received during normal operation. Based on the calibrated frequency signal and the established calibration curve, the processing module (208) determines the cadence RPM range corresponding to the rider's pedaling rate. The processing module (208) then evaluates this cadence RPM range along with the selected pedal assist mode (e.g., Eco, Normal, Tour, Power, or Boost) to determine the appropriate motor assistance level required. The processing module (208) may calculate the precise amount of motor assistance configured to the rider's real-time cadence requirements within the determined RPM range. By correlating the motor assistance with the rider's cadence, the assembly ensures a more intuitive and natural riding experience while optimizing energy efficiency. The processing module (208) controls the motor (214), which is likely housed within the gearbox housing (111) or another suitable enclosure. The motor (214) is driven with the determined assistance level, providing the necessary rotational output to the rear wheel through the gearbox, drivetrain, and other components.
The cadence sensor assembly may include or may be connected to one or more switches (211) to control the motor (214). These gate drivers (209) with one or more switches (211) are preferably high-frequency switches selected from, but not limited to, power transistors, silicon-controlled rectifiers (SCRs), metal-oxide-semiconductor field-effect transistors (MOSFETs), or insulated-gate bipolar transistors (IGBTs) or combination thereof. The processing module (208) in the cadence sensor assembly may play a crucial role in triggering the gate driver (209) with one or more switches (not shown) to control the motor (214) based on the determined motor assistance level. The processing module (208) then generates the appropriate control signals or gate signals to trigger the switching devices responsible for regulating the power supply to the motor (214). These switching devices act as electronic switches, controlling the flow of current or voltage to the motor windings. After determining the motor assistance level based on the rider's cadence RPM range and the selected pedal assist mode, the processing module (208) calculates the required amount of current or voltage to be supplied to the electric motor. This calculation considers factors such as the electrical characteristics of the motor (214), torque requirements, and the desired rotational speed.
Additionally, the electric bicycle may have an electric braking assembly with a lever and a user interface (212). The lever is configured to pull a brake wire (not shown) or cable, thereby actuating brake pads or calipers to engage with the wheel rim or disc brake rotor, allowing the rider to slow down or stop the bicycle which also acts as a kill switch to stop the motor while braking. The user interface (212) may include one or more components selected from, but not limited to, push buttons, switches, toggle switches, a display or combination thereof. The display may be selected from, but not limited to, LED, LCD, or touch enabled display. The user interface (212) may be configured to input one or more instructions to the processing module (208) such as, but not limited, initiating calibration process, pedal assist mode, or emergency shutting electric motor off.
The cadence sensor assembly (100) may also include other components, such as a noise filter (206) to remove electromagnetic interference from the frequency signal, a gate driver (209) to control power transistors that supply power to the motor (214) based on the determined motor assistance level, and a pedal assist mode selector (not shown) to allow the rider to choose the desired pedal assist mode (Eco, Normal, Tour, Power, or Boost). This assembly combines the compact and lightweight cadence sensor assembly (100) with a 750-watt BLDC motor or PMSMs motor and other necessary components to provide an efficient and intuitive electric bicycle riding experience. The adaptive motor assistance based on the rider's cadence RPM range ensures optimal energy efficiency while delivering a natural and responsive riding experience.
The invention has various advantages.
Compact and lightweight design: The cadence sensor assembly (100) achieves a compact and lightweight form factor by streamlining the architecture and reducing unnecessary components. This compact configuration may allow seamless integration with the mid-drive motor, improving overall bike ergonomics, handling, and reducing weight, which enhances performance and efficiency.
Simplicity and reduced components: By prioritizing simplicity in configuration and minimizing the number of components, the invention may lead to enhanced reliability and durability. Fewer components also may result in easier assembly, reduced manufacturing complexity, and lower production costs, making the assembly more cost-effective compared to traditional cadence sensors.
Minimal latency in data acquisition: The invention may achieve minimal latency in detecting and processing pedal motion through meticulous engineering and optimization of signal processing algorithms. This minimal latency may ensure real-time responsiveness and seamless coordination between the rider's input and the motor's assistance, improving the overall riding experience.
Adaptive motor assistance based on cadence RPM: Unlike traditional assemblies that provide a predefined assistance level based on the pedal assist mode, the invention may determine the motor assistance level based on the rider's actual cadence RPM range. The adaptive approach may improve energy efficiency by providing the right amount of assistance configured to the rider's needs, reducing unnecessary energy waste and extending the range of the electric bicycle. Improved overall riding experience: By correlating the motor assistance with the rider's real-time cadence requirements, the assembly may provide a more intuitive and natural riding experience. The motor assistance seamlessly may adapt to the rider's pedaling rate, enhancing the overall riding dynamics and user satisfaction.
Enhanced energy efficiency: The invention may achieve enhanced energy efficiency through precise calibration and segmentation of the cadence RPM into different ranges. By determining the optimal motor assistance level for each RPM range, the assembly may reduce unnecessary energy consumption, leading to improved battery life and extended range for the electric bicycle.
Reduced manufacturing complexity: The streamlined assembly requirements and minimized number of components may lead to improved manufacturing efficiency. The simplified design may reduce the complexity of the manufacturing process, resulting in cost savings and improved scalability for mass production.
Improved reliability and durability: The simplified configuration and reduced complexity of the cadence sensor assembly (100) may enhance its overall robustness and longevity. With fewer components and optimized integration, the assembly may be less susceptible to failures, ensuring reliable and consistent performance over an extended period.
Versatility: The cadence sensor assembly (100) may be adapted to various electric motor types, such as BLDC, IPM, PMSM, induction motors, or permanent-magnet DC motors. This versatility may allow flexibility in application and design, enabling the integration of the assembly with different electric bicycle configurations and motor technologies.
In general, the word “module”, as used herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, such as, for example, Java, C, embedded C or assembly. One or more software instructions in the modules may be embedded in firmware, such as an EPROM, EEPROM or flash memory. It will be appreciated that modules may comprise connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The modules described herein may be implemented as either software and/or hardware modules and may be stored in any type of computer-readable medium or other computer storage device.
Further, while one or more operations have been described as being performed by or otherwise related to certain modules, devices or entities, the operations may be performed by or otherwise related to any module, device or entity. As such, any function or operation that has been described as being performed by a module could alternatively be performed by a different server, by the cloud computing platform, or a combination thereof. It is implied that the techniques of the present disclosure might be implemented using a variety of technologies. For example, the methods described herein may be implemented by a series of computer-executable instructions residing on a suitable computer-readable medium. Suitable computer-readable media may include volatile (e.g., RAM) and/or non-volatile (e.g., ROM, disk) memory, carrier waves, and transmission media. Exemplary carrier waves may take the form of electrical, electromagnetic, or optical signals conveying digital data streams along a local network or a publicly accessible network such as the Internet.
It should also be understood that, unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “controlling” or “obtaining” or “computing” or “storing” or “receiving” or “determining” or the like, refer to the action and processes of a computer assembly, or similar electronic computing device, that processes and transforms data represented as physical (electronic) quantities within the computer assembly’s registers and memories into other data similarly represented as physical quantities within the computer assembly memories or registers or other such information storage, transmission or display devices.
Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and the appended claims. , Claims:We claim:
1. An electric bicycle adaptive pedal assist system using a cadence sensor assembly (100) having a pedal assembly with one or more pedals coupled to corresponding pedal shaft (106), a gearbox housing proximal to the pedal shaft (106), at least one wheel, and an electric motor configured to drive the at least one wheel, the pedal shaft (106) configured to rotate in response to pedaling motion on the one or more pedals; the complete assembly (100) comprising:
a magnet disc (1)4) coupled to the pedal shaft (106);
a cadence printed circuit board or cadence PCB (102) with at least one Hall sensor (1024) mounted in the gearbox housing; wherein at least one Hall sensor (1024) is positioned proximate to the magnet disc (104);
a processing module (208), wherein the processing module (208) is configured to:
receive a frequency signal corresponding to the rotation speed of the magnet disc (104) from at least one Hall sensor (1024);
calibrate the cadence sensor assembly (100) by mapping the frequency signal to predetermined cadence revolutions per minute or RPM to establish a calibration curve;
determine a cadence RPM range based on the calibrated frequency signal and the established calibration curve;
determine a motor assistance level based on the determined cadence RPM range and a selected pedal assist mode; wherein the motor assistance level is dynamically adjusted in real-time based on changes in the determined cadence RPM range during pedaling; and
trigger one or more switches that supply power to the electric motor to provide the determined motor assistance level to at least one wheel by adjusting a supply of power to the electric motor based on the determined motor assistance level.
2. The assembly (100) as claimed in claim 1, wherein for calibration, the processing module (208) is further configured to:
rotate the pedal shaft (106) at a predetermined cadence revolutions per minute or RPM; wherein the predetermined cadence revolutions per minute or RPM ranges from 2 to 110 revolutions per minute
measure the frequency signal from at least one Hall sensor (1024) during the rotation of the pedal shaft (106) at the predetermined cadence RPM;
map the measured frequency signal to the predetermined cadence RPM to establish a calibration curve; and
program and store the calibration curve for determining cadence RPM ranges based on received frequency signals during operation.
3. The assembly (100) as claimed in claim 1, wherein the magnet disc (104) pressed with magnets (108) is secured within a groove of the pedal shaft (106) by magnetic attraction.
4. The assembly (100) as claimed in claim 1, wherein the processing module (208) is further configured to calculate an amount of current required for the electric motor to provide the determined motor assistance level.
5. The assembly (100) as claimed in claim 1, further comprises a gate driver (209) coupled to the processing module (208) and configured to trigger one or more switches selected from power transistors, SCR, MOSFET, IGBT, or a combination thereof (211).
6. The assembly (100) as claimed in claim 1, further comprises a noise filter (206) configured to remove electromagnetic interference from the frequency signal received from at least one Hall sensor (1024).
7. The assembly (100) as claimed in claim 1, further comprises a selectable pedal assist mode selector or user interface (212) configured to allow the rider to select the pedal assist mode.
8. The assembly (100) as claimed in claim 1, wherein the pedal assist mode selected from Eco mode, Normal mode, Tour mode, Power mode and boost mode, wherein the processing module (208) determines the motor assistance level based on the detected cadence RPM range and the selected pedal assist mode.
9. The assembly (100) as claimed in claim 1, wherein the motor assistance level determined comprises a level of power or torque output provided by the motor (214) to assist the rider’s pedaling effort based on the detected cadence RPM and the selected pedal assist mode.
10. The assembly (100) as claimed in claim 1, wherein the cadence RPM ranges from a range of 30 RPM to 120 RPM based on the calibrated frequency signal and the established calibration curve.