US20050239600A1

Movatterモバイル変換

Info

Publication number: US20050239600A1
Application number: US10/831,429
Authority: US
Inventors: Shin-Lung Liang; Ping-Ru Lee
Original assignee: LIANG HSIU-SHUN; LU SHU-LAN
Current assignee: LIANG HSIU-SHUN; LU SHU-LAN
Priority date: 2004-04-23
Filing date: 2004-04-23
Publication date: 2005-10-27

Abstract

An apparatus for providing a dynamically variable resistive load during exercise includes a wheel unit, a resistance generator, a torque transfer device, an angle measuring device, and a control unit. The wheel unit rotates in response to exertion of a user-applied force during an exercise stroke. The resistance generator generates a resistive torque for resisting rotation of the wheel unit when the user-applied force is exerted. The torque transfer device transfers a fraction of the resistive torque from the resistance generator to the wheel unit. The angle measuring device detects angular rotation of the wheel unit during each exercise stroke. The control unit, in accordance with the angular rotation of the wheel unit during a current exercise stroke, controls the torque transfer device to adjust the fraction of the resistive torque that is transferred to the wheel unit.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a load for exercise equipment, more particularly to a method and apparatus for providing a dynamically variable resistive load during exercise.

2. Description of the Related Art

A known apparatus for providing a resistive load during exercise includes a wheel unit, a resistance generator, an electrically controlled torque transfer device, and a control unit. The wheel unit is operable so as to rotate in response to exertion of a user-applied force during an exercise stroke. The resistance generator, such as an electric motor, is operable so as to generate a resistive torque for resisting rotation of the wheel unit when the user-applied force is exerted. The torque transfer device, such as an electromagnetic mechanical particle clutch, couples the resistance generator to the wheel unit, and is operable so as to transfer a fraction of the resistive torque from the resistance generator to the wheel unit. The control unit is coupled to the resistance generator so as to control activation of the resistance generator and direction of the resistive torque generated by the resistance generator. The control unit is further coupled to the torque transfer device, and controls operation of the torque transfer device in order to gradually increase the fraction of the resistive torque that is transferred to the wheel unit with reference to a predetermined load variation curve during each exercise stroke.

While the aforesaid known apparatus provides a variable resistive load during exercise, it does not take into account the actual physical condition of the user during exercise. As a result, when the resistive load is too heavy, the user is likely to get injured due to over-exertion.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a method and apparatus for providing a dynamically variable resistive load during exercise that can overcome the aforesaid drawback of the prior art.

According to one aspect of this invention, there is provided a method for providing a dynamically variable resistive load during exercise. The method is implemented using an apparatus which includes a wheel unit that is operable so as to rotate in response to exertion of a user-applied force during an exercise stroke, a resistance generator that is operable so as to generate a resistive torque for resisting rotation of the wheel unit when the user-applied force is exerted, and an electrically controlled torque transfer device that couples the resistance generator to the wheel unit and that is operable so as to transfer a fraction of the resistive torque from the resistance generator to the wheel unit. The method comprises the steps of:

- a) detecting angular rotation of the wheel unit during each exercise stroke; and
- b) in accordance with the detected angular rotation of the wheel unit during a current exercise stroke, controlling the torque transfer device to adjust the fraction of the resistive torque that is transferred to the wheel unit.

According to another aspect of this invention, there is provided an apparatus for providing a dynamically variable resistive load during exercise. The apparatus comprises a wheel unit, a resistance generator, an electrically controlled torque transfer device, an angle measuring device, and a control unit. The wheel unit is operable so as to rotate in response to exertion of a user-applied force during an exercise stroke. The resistance generator is operable so as to generate a resistive torque for resisting rotation of the wheel unit when the user-applied force is exerted. The torque transfer device couples the resistance generator to the wheel unit, and is operable so as to transfer a fraction of the resistive torque from the resistance generator to the wheel unit. The angle measuring device detects angular rotation of the wheel unit during each exercise stroke. The control unit is coupled to the torque transfer device and the angle measuring device. In accordance with the angular rotation of the wheel unit detected by the angle measuring device during a current exercise stroke, the control unit controls the torque transfer device to adjust the fraction of the resistive torque that is transferred to the wheel unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:

FIG. 1 is a schematic side view of a multi-function exercise machine that incorporates the preferred embodiment of an apparatus for providing a dynamically variable resistive load according to the present invention;

FIG. 2 is a schematic block diagram of the preferred embodiment;

FIG. 3 is a schematic side view of the preferred embodiment;

FIG. 4 is a flowchart to illustrate operation of a control unit of the preferred embodiment; and

FIG. 5 is a flowchart to illustrate operation of a modified control unit of the preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1, the preferred embodiment of anapparatus3 for providing a dynamically variable resistive load according to the present invention is shown to be incorporated in amulti-function exercise machine2 that includes a knownpull unit21, a knownleg extension unit22, and a knowntread unit23. Atransmission device24 is provided to couple theapparatus3 to each of thepull unit21, theleg extension unit22 and thetread unit23. Thetransmission device24 includes rope means241 coupled to thepull unit21 and theleg extension unit22, belt means242 coupled to thetread unit23, and a set ofpulleys243 for controlling transmission direction of the rope and belt means241,242.

With further reference toFIGS. 2 and 3, theapparatus3 of this embodiment includes awheel unit51, aresistance generator7, an electrically controlledtorque transfer device8, anangle measuring device52, and acontrol unit6.

Thewheel unit51 is coupled to the rope means241 and the belt means242 of thetransmission device24. Thewheel unit51 is thus operable so as to rotate in response to exertion of a user-applied force on any one of thepull unit21, theleg extension unit22 and thetread unit23 during exercise. In this embodiment, thewheel unit51 includes awheel shaft512 mounted rotatably on theexercise machine2, and anoptical encoder wheel510 mounted co-rotatably on thewheel shaft512 and formed with a plurality of angularly displacedradial slots511.

Theresistance generator7 is mounted on theexercise machine2, and includes anelectric motor72 that is operable so as to generate a resistive torque for resisting rotation of thewheel unit51 when the user-applied force is exerted. A knowntransmission unit73, which includes two

transmission wheels

731,732 and atransmission belt733 trained on the

transmission wheels

731,732, is used to transmit the resistive torque generated by themotor72 to thetorque transfer device8.

Thetorque transfer device8 couples thetransmission unit73 of theresistance generator7 to thewheel shaft512 of thewheel unit51, and is operable so as to transfer a fraction of the resistive torque from theresistance generator7 to thewheel unit51. In this embodiment, thetorque transfer device8 includes a conventional electromagnetic mechanical particle clutch. Since the feature of the invention does not reside in the specific construction of the knowntorque transfer device8, details of the same are omitted herein for the sake of brevity.

Theangle measuring device52 is mounted on theexercise machine2 proximate to thewheel unit51, and serves to detect angular rotation of thewheel unit51 during each exercise stroke when thepull unit21 or theleg extension unit22 is in use. In this embodiment, theangle measuring device52 includes a known photoelectric sensor associated operably with theoptical encoder wheel510 of thewheel unit51. Preferably, theradial slots511 of theoptical encoder wheel510 are formed at 10-degree intervals.

Thecontrol unit6 is coupled to thetorque transfer device8, theangle measuring device52 and theresistance generator7, and includes acontrol panel61 for inputting user settings, aprocessor62 connected to thecontrol panel61 and theangle measuring device52, amotor driver65 connected to theprocessor52 and theelectric motor72 of theresistance generator7 for controlling activation of theelectric motor72 and direction of the resistive torque generated by theelectric motor72, a digital-to-analog (D/A)converter63 connected to theprocessor62, and acurrent controller64 connected to the D/A converter63 and thetorque transfer device8 for controlling operation of thetorque transfer device8.

Thecontrol panel61 can be operated to select the type of exercise to be performed by the user, i.e., which one of thepull unit21, theleg extension unit22 and thetread unit23 is intended to be used, and a target resistive force value for the exercise to be performed by the user. Thecontrol panel61 can be disposed in front of the pull and

leg extension units

21,22, or in front of thetread unit23 to facilitate user operation.

Depending on the type of exercise to be performed, theprocessor62 controls activation of theelectric motor72 of theresistance generator7 through themotor driver65 such that the resistive torque generated by theresistance generator7 can resist rotation of thewheel unit51 due to application of the user-exerted force on the selected one of thepull unit21, theleg extension unit22, and thetread unit23.

Theprocessor62 has predetermined load variation curves for the different types of exercise stored therein. Since the feature of the present invention does not reside in the load variation curves, which are obtained through known techniques, a detailed description of the same is omitted herein for the sake of brevity. Theprocessor62 receives the user settings inputted through thecontrol panel61, and calculates different resistive load values with reference to the user settings and the load variation curve for the type of exercise to be performed by the user. Thereafter, with further reference to the angular rotation of thewheel unit51 detected by theangle measuring device52, theprocessor62 generates varying torque control outputs that correspond to the calculated resistive load values.

The D/A converter63 receives the torque control output of theprocessor62, and converts the same into an analog control signal. Thecurrent controller64 subsequently converts the control signal into a control current that is supplied to an electromagnet (not shown) of thetorque control device8. In response to the control current, thetorque control device8 adjusts the fraction of the resistive torque that is transferred from theresistance generator7 to thewheel unit51, thereby resulting in a variable resistive load during exercise.

FIG. 4 is a flowchart to illustrate operation of a preferred implementation of thecontrol unit6. In the flowchart ofFIG. 4, it is assumed that theleg extension unit22 was selected by the user, and the user inputted 30 kilograms as his target resistive force value. During an exercise stroke, the user exerts a force to move theleg extension unit22 with the use of his legs such that the user's legs are moved from an initial position, where the user's legs stand uprightly on the ground, toward a fully extended position, i.e., the user's legs are substantially horizontal. Theangle measuring device52 detects the angular rotation of thewheel unit51 during each exercise stroke, and provides the detected information to theprocessor62. Theprocessor62 gradually increases the torque control output thereof with reference to the predetermined load variation curve for theleg extension unit22 in case of an increase in angular displacement of thewheel unit51 from an initial position, and gradually decreases the torque control output with reference to the same predetermined load variation curve for theleg extension unit22 in case of a decrease in the angular displacement of thewheel unit51 from the initial position. For instance, during an initial stage of a current exercise stroke, the torque control output of theprocessor62 can be set to 20% of the target resistive force value. The torque control output is then gradually increased to increase the fraction of the resistive force that is transferred to thewheel unit51 as the angular displacement of thewheel unit51 from its initial position increases. When the user's legs are at the fully extended position, the torque control output of theprocessor62 can be set to correspond to 120% of the target resistive force value, i.e., 36 kilograms. Thereafter, when the user's legs are moved from the fully extended position back to the initial position, theprocessor62 gradually decreases its torque control output from an initial value corresponding to 40% of the target resistive force value, i.e., 12 kilograms, to a value corresponding to 0% of the target resistive force value (which is the resistive force transferred to thewheel unit51 when the user's legs are at the initial position). Since the resistive load transferred to thewheel unit51 varies with the measured angular displacement of thewheel unit51, the risk of injury can be reduced to a minimum during exercise.

Preferably, theprocessor62 is configured to control thecontrol panel61 to show the current resistive load transferred to thewheel unit51 thereon for user monitoring purposes.

FIG. 5 is a flowchart to illustrate operation of another preferred implementation of thecontrol unit6. In the flowchart ofFIG. 5, the fraction of the resistive torque is increased upon detection that the time for thewheel unit51 to reach a predetermined angular displacement during the current exercise stroke is smaller than a first threshold, and is reduced upon detection that the time for thewheel unit51 to reach the predetermined angular displacement during the current exercise stroke is greater than a second threshold.

In the flowchart ofFIG. 5, it is assumed that theleg extension unit22 was selected by the user, and that the standard time period for completing a lifting action of an exercise stroke ranges from 1.6 to 2.4 seconds. During an initial exercise stroke, the torque control output of theprocessor62 can be set to correspond to a 20-kilogram resistive load. If the time that took for the user to move his legs from the initial position to the fully extended position is smaller than 1.6 seconds (the first threshold, t_min), this indicates that the resistive load is too small, and thecontrol unit6 controls thetorque transfer device8 to increase the resistive torque transferred to thewheel unit51 to 25 kilograms for the succeeding exercise stroke. On the other hand, if the time that took for the user to move his legs from the initial position to the fully extended position is greater than 2.4 seconds (the second threshold, t_max), this indicates that the resistive load is too heavy, and thecontrol unit6 controls thetorque transfer device8 to reduce the resistive force transferred to thewheel unit51 to 15 kilograms for the succeeding exercise stroke. As a result, the resistive load is dynamically varied according to the actual condition of the user during exercise in order to minimize the risk of injury.

Preferably, theprocessor62 of thecontrol unit6 is adapted to be coupled to anexternal computer620 to permit downloading of the load variation curves for the different types of exercise therefrom.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.