Resistance-adjustable fitness device and resistance control method therefor

Abstract

Disclosed in the present invention are a resistance-adjustable fitness device and a resistance control method therefor. The fitness device comprises an operation portion, a connection portion, a connection portion adjustment module and a motor module. The operation portion is used by a user to operate. The connection portion is connected to the operation portion, and the connection portion adjustment module is used for correspondingly adjusting a release length of the connection portion when the user operates the operation portion. The motor module controls the connection portion adjustment module on the basis of the release length. When it is determined that the release length is less than a critical length value, the motor module controls the connection portion adjustment module according to a predetermined torque, so that the connection portion generates a fixed resistance. When it is determined that the release length is greater than or equal to the critical length value, the motor module controls the connection portion adjustment module according to a variable torque, so that the connection portion generates a variable resistance.

Description

Adjustable resistance fitness equipment and its resistance control methods Invention Field

[0001] This invention relates to a fitness device and its control method, and more particularly to a fitness device with adjustable resistance and its resistance control method. Background Technology

[0002] Compared to stable resistance training, unstable resistance training can stimulate more muscle groups in the body at the same time, so more and more athletes are starting to try unstable resistance training to improve training efficiency.

[0003] When athletes perform unstable resistance training, they need to attach resistance bands to bar plates or kettlebells and then suspend the bands from the bar. Furthermore, athletes must adjust the weight of the bar plates or kettlebells based on their performance to achieve effective training. Therefore, athletes need to prepare various weights of bar plates and kettlebells and have sufficient indoor space to store them for unstable resistance training, which is not very convenient.

[0004] Invention Overview

[0005] The technical problem to be solved by the present invention is to provide an adjustable resistance fitness device and its resistance control method, which addresses the shortcomings of the prior art.

[0006] To address the aforementioned technical problems, one technical solution adopted by this invention is to provide an adjustable resistance fitness device. The fitness device includes an operating unit, a connecting unit, a connecting unit adjustment module, and a motor module. The operating unit is for user operation. The connecting unit is connected to the operating unit, and the connecting unit adjustment module adjusts the release length of the connecting unit accordingly when the user operates the operating unit. The motor module controls the connecting unit adjustment module based on the release length. When the motor module determines that the release length is less than a length threshold, it controls the connecting unit adjustment module with a predetermined torque to generate fixed resistance in the connecting unit. When the motor module determines that the release length is greater than or equal to the length threshold, it controls the connecting unit adjustment module with a variable torque to generate variable resistance in the connecting unit.

[0007] One of the beneficial effects of the present invention is that the adjustable resistance fitness equipment and its resistance control method provided by the present invention allow athletes to perform unstable resistance training anytime and anywhere without the need to prepare bar plates and kettlebells of various weights or the indoor space to place the bar plates and kettlebells.

[0008] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0009] Figure 1 is a functional block diagram of the adjustable resistance fitness device of the present invention.

[0010] Figure 2 is a schematic diagram of the fitness equipment of the present invention in use.

[0011] Figure 3 shows the circuit diagram of the motor module.

[0012] Figure 4A shows the relationship between the U-phase voltage and the mechanical angle of the motor of the present invention.

[0013] Figure 4B is a graph showing the relationship between the V-phase voltage and the mechanical angle of the motor of the present invention.

[0014] Figure 4C is a graph showing the relationship between the W-phase voltage and the mechanical angle of the motor of the present invention.

[0015] Figure 5A shows the relationship between the U-phase voltage and electrical angle of the motor of the present invention.

[0016] Figure 5B shows the relationship between the V-phase voltage and electrical angle of the motor of the present invention.

[0017] Figure 5C is a graph showing the relationship between the W-phase voltage and electrical angle of the motor of the present invention.

[0018] Figure 6 is a timing diagram of the first embodiment of the fitness device of the present invention that generates unstable resistance.

[0019] Figure 7 is a timing diagram of a second embodiment of the fitness device of the present invention that generates unstable resistance.

[0020] Figure 8 is a timing diagram of the third embodiment of the fitness device of the present invention generating unstable resistance.

[0021] Figure 9 is a timing diagram of the fourth embodiment of the fitness device of the present invention generating unstable resistance.

[0022] Figure 10 is a flowchart of the resistance control method of the fitness equipment according to the first embodiment of the present invention.

[0023] Figure 11 is a flowchart of the resistance control method of the fitness equipment according to the second embodiment of the present invention.

[0024] Figure 12 is a flowchart of the resistance control method of the fitness equipment according to the third embodiment of the present invention.

[0025]

Symbol Explanation

[0026] Detailed description of the invention

[0027] Figure 1 is a functional block diagram of the adjustable resistance fitness device of the present invention. The fitness device includes an operation unit 1, a connecting unit 2, a connecting unit adjustment module 3, a motor module 4, a rotational position sensor 5, and a feedback resistor circuit 6. The operation unit 1 is used for user operation, and the connecting unit 2 connects the operation unit 1 and the connecting unit adjustment module 3.

[0028] The motor module 4 includes a motor driver 41, a switching circuit 42, and a motor 43. The motor driver 41 includes a microcontroller unit 411 connected to a gate driver 412. The microcontroller unit 411 is connected to the gate driver 412. The switching circuit 42 is connected between the gate driver 412 and the motor 43. The motor 43 is connected between the switching circuit 42 and the connection adjustment module 3.

[0029] The microcontroller unit 411 outputs a switch control signal to the gate driver 412. When the state of the switch control signal changes, the duration for which the switch circuit 42 is in the conducting state also changes. When the duration for which the switch circuit 42 is in the conducting state changes, the output torque of the motor 43 also changes.

[0030] For example, the switching control signal of the microcontroller unit 411 can be a pulse width modulation (PWM) signal. When the duty cycle of the PWM signal increases, the duration of the on-state of the switching circuit 42 increases, thereby increasing the output torque of the motor 43. Conversely, when the duty cycle of the PWM signal decreases, the duration of the on-state of the switching circuit 42 decreases, thereby decreasing the output torque of the motor 43.

[0031] For example, the microcontroller unit 411 can also directly output a changing analog voltage signal. When the voltage value of the analog voltage signal increases, the output torque of the motor 43 increases. Conversely, when the voltage value of the analog voltage signal decreases, the output torque of the motor decreases.

[0032] The rotary position sensor 5 is connected between the motor 43 and the microcontroller unit 411. The rotary position sensor 5 includes, for example, an amplifier circuit, an analog-to-digital conversion circuit, a bandpass filter, a phase-locked loop angle detection circuit, a zero-crossing angle detection circuit, and an averaging filter, and can be used with other related circuit components and firmware to achieve the following functions.

[0033] When the rotor of motor 43 rotates, the rotation position sensor 5 detects the rotation position of the rotor of motor 43. The microcontroller unit 411 determines the release length of the connection part 2 based on the rotation position of the rotor of motor 43, and the microcontroller unit 411 determines whether to change the state of the switch control signal based on the release length of the connection part 2.

[0034] For example, the rotary position sensor 5 detects the mechanical angle of the rotor of the motor 43 and converts the mechanical angle into an electrical angle. The microcontroller unit 411 determines the release length L of the connection part 2 based on the electrical angle, and determines whether to change the duty cycle of the pulse width modulation signal based on the release length.

[0035] When the microcontroller unit 411 determines that the release length of the connection part 2 is less than the length threshold, the duty cycle of the switch control signal of the microcontroller unit 411 is a fixed value. When the duty cycle of the switch control signal remains fixed, the duration for which the switch circuit 42 is in the conducting state is a fixed value.

[0036] When the switching circuit 42 is in the conducting state for a fixed duration, the motor 43 drives the connecting part adjustment module 3 to rotate at a fixed speed with a predetermined torque (i.e., fixed torque). When the connecting part adjustment module 3 rotates at a fixed speed, a stable resistance is generated on the connecting part 2.

[0037] When the microcontroller unit 411 determines that the release length L of the connection part 2 is greater than or equal to the length threshold, the duty cycle of the switch control signal of the microcontroller unit 411 is a variable value. When the duty cycle of the switch control signal is a variable value, the duration for which the switch circuit 42 is in the conducting state is also a variable value.

[0038] When the duration of the conducting state of the switching circuit 42 is variable, the output torque of the motor 43 varies with time, thereby driving the connecting part adjustment module 3 to rotate at a variable speed. When the connecting part adjustment module 3 rotates at a variable speed, unstable resistance is generated on the connecting part 2.

[0039] Feedback resistor circuit 6 is connected between switching circuit 42 and microcontroller unit 411. When switching circuit 42 outputs voltage to motor 43, a corresponding current is generated in feedback resistor circuit 6. The larger the current detected by microcontroller unit 411 in feedback resistor circuit 6, the greater the current output torque of motor 43. Conversely, the smaller the current detected by microcontroller unit 411 in feedback resistor circuit 6, the smaller the current output torque of motor 43.

[0040] Figure 2 is a schematic diagram of the fitness equipment of the present invention in use. Referring to Figures 1 and 2 together, the operating part 1 is a rod, the connecting part 2 is a rope, and the connecting part adjustment module 3 is a cable reel. The two ends of the rope are connected to the rod and the cable reel, respectively. When the user supports the rod in a squatting position, the release length L of the rope is less than the length critical value, and the motor 43 drives the cable reel to rotate at a fixed speed with a predetermined torque. When the cable reel rotates at a fixed speed, a fixed tension is generated on the rope, and the user must overcome the fixed tension on the rope to stably support the rod. When the user gradually changes from a squatting position to a standing position, the release length L of the rope gradually increases and drives the cable reel to rotate, and the rotation of the cable reel drives the rotor of the motor 43 to rotate. When the rotor of the motor 43 rotates, the rotation position sensor 5 detects the mechanical angle of the rotor and converts the mechanical angle into an electrical angle. The microcontroller unit 411 calculates the number of rotations and the direction of rotation of the rotor based on the electrical angle of the rotor of the motor 43, and calculates the release length L of the rope based on the number of rotations and the direction of rotation of the rotor of the motor 43.

[0041] For example, the rotor of motor 43 can be connected to the cable reel via a reduction gear, so there is a fixed ratio between the number of rotations of the rotor of motor 43 and the number of rotations of the cable reel. The microcontroller unit 411 calculates the number of rotations of the cable reel based on the number of rotations of the rotor of motor 43. Since the length of rope released by the cable reel in one rotation is fixed, the microcontroller unit 411 calculates the release length L of the rope based on the number of rotations of the cable reel.

[0042] When the microcontroller unit 411 determines that the release length L of the rope is greater than or equal to the critical length value, the motor 43 drives the reel to rotate at a variable speed with varying torque. When the reel rotates at a variable speed, a variable tension is generated on the rope. The user must adjust the tension to stably support the rod. In this way, the user can achieve the effect of unstable resistance training.

[0043] Figure 3 shows the circuit diagram of motor module 4. The switching circuit 42 includes three upper-bridge switches SW1, SW2, and SW3, and three lower-bridge switches SW4, SW5, and SW6. The upper-bridge switches SW1, SW2, and SW3, and the lower-bridge switches SW4, SW5, and SW6 are metal-oxide-semiconductor field-effect transistors (MOSFETs). Upper-bridge switch SW1 is connected between the voltage source VDD and output node N1, while lower-bridge switch SW4 is connected between output node N1 and ground. Upper-bridge switch SW2 is connected between the voltage source VDD and output node N2, while lower-bridge switch SW5 is connected between output node N2 and ground. Upper-bridge switch SW3 is connected between the voltage source VDD and output node N3, and lower-bridge switch SW6 is connected between output node N3 and ground.

[0044] The microcontroller unit 411 outputs six pulse width modulation (PWM) signals to the gate driver 412. The six outputs of the gate driver 412 are respectively connected to the three gates of the upper bridge switches SW1, SW2, and SW3, and the three gates of the lower bridge switches SW4, SW5, and SW6. The microcontroller unit 411 controls the duration of conduction of each of the upper bridge switches SW1, SW2, and SW3, and the duration of conduction of each of the lower bridge switches SW4, SW5, and SW6 by controlling the duty cycle of each PWM signal.

[0045] The motor 43 includes a U-phase winding 431, a V-phase winding 432, and a W-phase winding 433, which are respectively connected to the output nodes N1, N2, and N3 of the switching circuit 42.

[0046] The feedback resistor circuit 6 includes three resistors R, each with a first terminal and a second terminal. The three first terminals of the three resistors R are connected to output nodes N1, N2, and N3, respectively, while the three second terminals of the three resistors R are connected to the microcontroller unit 411. When a node voltage is generated on output node N1, N2, or N3, a corresponding current is generated in resistor R. When the microcontroller unit 411 detects a larger current in resistor R, it indicates that the current output torque of motor 43 is greater. Conversely, when the microcontroller unit 411 detects a smaller current in resistor R, it indicates that the current output torque of motor 43 is smaller.

[0047] Figure 4A is a graph showing the relationship between the U-phase voltage and mechanical angle of the motor of the present invention. Figure 4B is a graph showing the relationship between the V-phase voltage and mechanical angle of the motor of an embodiment of the present invention. Figure 4C is a graph showing the relationship between the W-phase voltage and mechanical angle of the motor of an embodiment of the present invention. Figure 5A is a graph showing the relationship between the U-phase voltage and electrical angle of the motor of an embodiment of the present invention. Figure 5B is a graph showing the relationship between the V-phase voltage and electrical angle of the motor of an embodiment of the present invention. Figure 5C is a graph showing the relationship between the W-phase voltage and electrical angle of the motor of an embodiment of the present invention. Referring to Figures 4A-4C and 5A-5C, the motor 43 is a three-phase three-pole brushless DC motor. When the mechanical angle of the rotor of the motor 43 increases from 0 degrees to 20 degrees, the electrical angle of the rotor of the motor 43 increases from 0 degrees to 60 degrees. The voltage of the U-phase winding 431 is positive, the voltage of the V-phase winding 432 is zero, and the voltage of the W-phase winding 433 switches from positive to zero. When the mechanical angle of the rotor of motor 43 increases from 20 degrees to 40 degrees, the electrical angle of the rotor of motor 43 increases from 60 degrees to 120 degrees. The voltage of U-phase winding 431 is positive, the voltage of V-phase winding 432 switches from zero to positive, and the voltage of W-phase winding 433 is zero. When the mechanical angle of the rotor of motor 43 increases from 40 degrees to 60 degrees, the electrical angle of the rotor of motor 43 increases from 120 degrees to 180 degrees. The voltage of U-phase winding 431 switches from positive to zero, the voltage of V-phase winding 432 is positive, and the voltage of W-phase winding 433 is zero, and so on.

[0048] When the duration of the on-state of the upper or lower bridge switch of the switching circuit 42 increases, the voltage values ​​of the U-phase winding 431, V-phase winding 432, or W-phase winding 433 increase relatively, thereby increasing the output torque of the motor 43. Conversely, when the duration of the on-state of the upper or lower bridge switch of the switching circuit 42 decreases, the voltage values ​​of the U-phase winding 431, V-phase winding 432, or W-phase winding 433 decrease relatively. This alters the output torque of the motor 43.

[0049] Figure 6 is a timing diagram of a first embodiment of the fitness device of the present invention generating unstable resistance. As shown in Figure 6, before time point T1, since the release length L of the rope has not reached the length critical value, the motor driver 41 controls the motor 43 to rotate with a fixed torque. After time point T1, since the release length L of the rope is equal to or greater than the length critical value, the motor driver 41 controls the motor 43 to rotate with a variable torque. When the motor 43 of the fitness device rotates with a variable torque, unstable resistance is generated on the connection part 2 of the fitness device. In this embodiment, the variable torque varies with time within a first torque variation range according to a first frequency, wherein the first torque variation range includes a first torque upper limit VT1 and a first torque lower limit LT1.

[0050] Using the fitness equipment shown in Figure 6, users are not limited by location and can perform unstable weight training at any time. Because the fitness equipment can provide both stable and unstable resistance, users can stimulate more muscle groups in the body, thus improving training efficiency.

[0051] Figure 7 is a timing diagram of a second embodiment of the fitness device of the present invention generating unstable resistance. Referring to Figure 7, before time point T1, since the release length L of the rope has not reached the length critical value, the motor driver 41 controls the motor 43 to rotate with a fixed torque. After time point T1, since the release length L of the rope is equal to or greater than the length critical value, the motor driver 41 controls the motor 43 to rotate with a variable torque. When the motor 43 of the fitness device rotates with a variable torque, unstable resistance is generated on the connection part 2 of the fitness device. In this embodiment, after time point T1 and before time point T2, the variable torque varies with time within a torque variation range according to a first frequency. After time point T2, the motor driver 41 controls the variable torque to vary with time within a first torque variation range according to a second frequency, wherein the first torque variation range includes a first torque upper limit VT1 and a first torque lower limit LT1. When the user becomes accustomed to the first resistance variation, the frequency of resistance variation is increased. In this way, the user must adjust their force more quickly, improve the reaction speed of the body's muscle groups, and have higher training efficiency.

[0052] Figure 8 is a timing diagram of the third embodiment of the fitness device of the present invention generating unstable resistance. As shown in Figure 8, before time point T1, since the release length L of the rope is not greater than the length critical value, the motor driver 41 controls the motor 43 to rotate with a fixed torque. After time point T1, since the release length L of the rope is equal to or greater than the length critical value, the motor driver 41 controls the motor 43 to rotate with a variable torque. When the motor 43 of the fitness device rotates with a variable torque, unstable resistance is generated on the connection part 2 of the fitness device. In this embodiment, after time point T1 and before time point T3, the variable torque first varies with time within a first torque variation range according to a first frequency, wherein the first torque variation range includes a first torque upper limit VT1 and a first torque lower limit LT1. After time point T3, the motor driver 41 controls the variable torque to vary with time within a second torque variation range according to a first frequency, wherein the second torque variation range includes a second torque upper limit VT2 and a second torque lower limit LT2. The unstable resistance of the fitness device in Figure 8 varies in two variation ranges. Once the body becomes accustomed to the current range of resistance variation, increasing the range of resistance variation will provide greater stimulation to the user's muscle groups and promote muscle growth.

[0053] Figure 9 is a timing diagram of the fourth embodiment of the fitness device of the present invention generating unstable resistance. As shown in Figure 9, before time point T1, since the release length L of the rope has not reached the length critical value, the motor driver 41 controls the motor 43 to rotate with a fixed torque. After time point T1, since the release length L of the rope is equal to or greater than the length critical value, the motor driver 41 controls the motor 43 to rotate with a variable torque. When the motor 43 of the fitness device rotates with a variable torque, unstable resistance is generated on the connection part 2 of the fitness device. In this embodiment, after time point T1 and before time point T4, the variable torque first varies with time within a first torque variation range according to a first frequency, wherein the first torque variation range includes a first torque upper limit VT1 and a first torque lower limit LT1. After time point T4, the motor driver 41 controls the variable torque to vary with time within a second torque variation range according to a second frequency, wherein the second torque variation range includes a second torque upper limit VT2 and a second torque lower limit LT2. When the user becomes accustomed to the first type of resistance variation, the resistance variation range and the frequency of resistance variation are increased simultaneously. In this way, users must adjust their force more quickly, improve the speed of muscle group response, and achieve higher training efficiency.

[0054] Figure 10 is a flowchart of the resistance control method of the fitness device according to the first embodiment of the present invention. Referring to Figure 10, in step S101, an operation unit 1 is configured for operation by the user. In step S102, a connecting part 2 is configured to connect to the operation unit 1. In step S103, a rotational position sensor 5 is configured between the motor 43 and the motor driver 41. In step S104, the rotational position sensor 5 detects the mechanical angle of the rotor of the motor 43 and converts the mechanical angle into an electrical angle. In step S105, the motor driver 41 determines whether the release length of the connecting part 2 is greater than or equal to a length threshold value based on the electrical angle of the rotor of the motor 43.

[0055] When the release length of the connecting part 2 is less than the length critical value, proceed to step S106. In step S106, the motor driver 41 controls the motor 43 to rotate with a fixed torque, so that the connecting part 2 generates stable resistance. When the release length of the connecting part 2 is greater than or equal to the length critical value, proceed to step S107. In step S107, the motor driver 41 controls the motor 43 to rotate with a variable torque, the variable torque varying according to a first frequency within a first torque variation range, so that the connecting part 2 generates unstable resistance.

[0056] Figure 11 is a flowchart of the resistance control method of the fitness equipment according to the second embodiment of the present invention. Referring to Figure 11, in step S201, the operation unit 1 is configured for operation by the user. In step S202, the connecting part 2 is configured to connect to the operation unit 1. In step S203, the rotational position sensor 5 is configured between the motor 43 and the motor driver 41. In step S204, the rotational position sensor 5 detects the mechanical angle of the rotor of the motor 43 and converts the mechanical angle into an electrical angle. In step S205, the motor driver 41 determines whether the release length of the connecting part 2 is greater than or equal to a length critical value based on the electrical angle of the rotor of the motor 43. When the release length of the connecting part 2 is less than the length critical value, the process proceeds to step S206. In step S206, the motor driver 41 controls the motor 43 to rotate with a fixed torque so that the connecting part 2 generates stable resistance. When the release length of the connecting part 2 is greater than or equal to the length critical value, the process proceeds to step S207. In step S207, the motor driver 41 controls the motor 43 to rotate with a variable torque. The variable torque varies within a first torque variation range according to a first frequency, causing unstable resistance to be generated at the connection part 2. In step S208, the motor driver 41 determines whether the time for which the torque of the motor 43 varies according to the first frequency has reached a time threshold. If the time for which the torque of the motor 43 varies according to the first frequency has reached the time threshold, proceed to step S209. In step S209, the motor driver 41 controls the torque of the motor 43 to vary within a second torque variation range according to the first frequency, causing unstable resistance to be generated at the connection part 2. If the time for which the torque of the motor 43 varies according to the first frequency has not reached the time threshold, return to step S207.

[0057] Figure 12 is a flowchart of the resistance control method of the fitness equipment according to the third embodiment of the present invention. Referring to Figure 12, in step S301, the operation unit 1 is configured for operation by the user. In step S302, the connecting part 2 is configured to connect to the operation unit 1. In step S303, the rotational position sensor 5 is configured between the motor 43 and the motor driver 41. In step S304, the rotational position sensor 5 detects the mechanical angle of the rotor of the motor 43 and converts the mechanical angle into an electrical angle. In step S305, the motor driver 41 determines whether the release length of the connecting part 2 is greater than or equal to a length critical value based on the electrical angle of the rotor of the motor 43. When the release length of the connecting part 2 is less than the length critical value, the process proceeds to step S1106. In step S306, the motor driver 41 controls the motor 43 to rotate with a fixed torque so that the connecting part 2 generates stable resistance. When the release length of the connecting part 2 is greater than or equal to the length critical value, the process proceeds to step S307. In step S307, the motor driver 41 controls the torque of the motor 43 to vary within a first torque variation range according to a first frequency, thereby generating unstable resistance in the connecting part 2. In step S308, the motor driver 41 determines whether the time for the torque of the motor 43 to vary according to the first frequency has reached a time threshold. If the time for the torque of the motor 43 to vary according to the first frequency has reached the time threshold, proceed to step S309. In step S309, the motor driver 41 controls the torque of the motor 43 to vary within the first torque variation range according to a second frequency, thereby generating unstable resistance in the connecting part 2. If the time for the torque of the motor 43 to vary according to the first frequency has not reached the time threshold, return to step S307.

[0058] One of the beneficial effects of the present invention is that the adjustable resistance fitness equipment and its resistance control method provided by the present invention allow athletes to perform unstable resistance training anytime and anywhere without the need to prepare bar plates and kettlebells of various weights or the indoor space to place the bar plates and kettlebells.

[0059] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification and drawings are included in the scope of the patent application of the present invention.

Claims

1. A fitness device with adjustable resistance, characterized in that, include: An operating unit for operation by a user; A connecting part is connected to the operating part; A connection adjustment module is used to adjust a release length of the connection corresponding to the user's operation of the operating unit; and A motor module controls the connection adjustment module according to the release length; When the motor module determines that the release length is less than a length threshold, it controls the connection adjustment module with a predetermined torque to generate a fixed resistance in the connection. When the motor module determines that the release length is greater than or equal to the length threshold, it controls the connection adjustment module with a variable torque to generate a variable resistance in the connection.

2. The adjustable resistance fitness equipment as described in claim 1, characterized in that, The motor module includes a motor driver, a switching circuit, and a motor. The motor driver is connected to the switching circuit, the switching circuit is connected to the motor, and the motor is connected to the connection adjustment module.

3. The adjustable resistance fitness equipment as described in claim 2, characterized in that, It further includes: a rotational position sensor connected to the motor and the motor driver, the rotational position sensor detecting a rotational position of the motor, and the motor driver determining the release length based on the rotational position.

4. The adjustable resistance fitness equipment as described in claim 1, characterized in that, The variable torque varies within a torque variation range according to a fixed frequency.

5. The adjustable resistance fitness device as described in claim 1, characterized in that the variable torque varies within a torque variation range according to a first frequency, and when the duration of continuous variation of the variable torque reaches a time threshold, the variable torque varies within the torque variation range according to a second frequency.

6. The adjustable resistance fitness equipment as described in claim 1, characterized in that, The variable torque varies within a first torque variation range at a fixed frequency. When the duration of the variable torque variation reaches a time threshold, the variable torque varies within a second torque variation range at the fixed frequency.

7. A resistance control method for fitness equipment, characterized in that, include: An operating unit is configured for operation by a user; A connecting part is configured to connect to the operating part; A motor module determines a release length of the connection portion; When the release length is less than a length threshold, the motor module outputs a predetermined torque to generate a fixed resistance at the connection; and When the release length is greater than or equal to the length threshold, the motor module outputs a variable torque, which causes a variable resistance to be generated on the connection part.

8. The resistance control method for fitness equipment as described in claim 7, characterized in that, Including: A rotary position sensor is configured; the rotary position sensor detects the rotational position of a motor in the motor module. The motor driver of the motor module determines the release length based on the rotational position.

9. The resistance control method for fitness equipment as described in claim 7, characterized in that, The variable torque varies within a first torque variation range at a fixed frequency. When the duration of the variable torque variation reaches a time threshold, the variable torque varies within a second torque variation range at the fixed frequency.

10. The resistance control method for the fitness equipment as described in claim 7, characterized in that, The variable torque varies within a torque variation range according to a first frequency. When the duration of the variable torque variation reaches a time threshold, the variable torque varies within the torque variation range according to a second frequency.

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