Treadmill and safety control circuit thereof

Abstract

The utility model relates to a safety control circuit of a running machine, which comprises a single chip microcomputer, a pulsating current acquisition circuit and an average current acquisition circuit. The pulsating current acquisition circuit and the average current acquisition circuit are connected in parallel between the positive electrode of the first motor and the sampling resistor, and the output ends of the two acquisition circuits are electrically connected with the single-chip microcomputer. The pulsating current acquisition circuit comprises a program control gain amplifier, and the output end of the average current acquisition circuit is further electrically connected with the program control gain amplifier. The output end of the average current acquisition circuit is connected with the single-chip microcomputer and a program control gain amplifier in the pulsating current acquisition circuit, the average current data acquisition circuit automatically adjusts the gain of the pulsating current data acquisition circuit, accurate acquisition of ground-touching pulsating current data of sports feet is guaranteed, the running performance state is monitored in real time, and the running safety is improved. And the speed of the running belt is adjusted and reduced in time in an abnormal state, so that the safety of executing a running exercise scheme is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of treadmills, in particular to a treadmill and a safety control circuit thereof. Background Art

[0002] As an aerobic fitness equipment that is not affected by weather and can easily control the intensity of exercise by adjusting speed and slope, electric treadmills are increasingly entering households to meet the needs of home fitness. However, as a fitness equipment for people to exercise passively, electric treadmills have certain safety risks, especially in a home environment, where there is no professional coach to evaluate and guide the intensity of exercise and monitor the running process. Excessive exercise intensity, too low exercise intensity, incorrect running posture, poor physical condition, etc. often cause poor exercise results or sports injuries; although there are some public technologies that evaluate exercise ability in advance and formulate running plans, and automatically adjust the running speed and slope through heart rate monitoring during the process to solve the problem of exercise intensity control; however, these technologies are one-sided, because the exercise heart rate only reflects the body's reaction to the internal state of exercise intensity, and is not a comprehensive feedback of the body's state. There are certain risks in the automatic adjustment of exercise intensity during the evaluation process or the execution of the exercise plan. Utility Model Content

[0003] The utility model aims to provide a treadmill and a safety control circuit thereof, which can monitor the dynamic parameters of the user's running posture in real time, and ensure the sports safety to the maximum extent while ensuring the sports effect.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] A treadmill safety control circuit is used to control the first motor that drives the treadmill belt to operate. The safety control circuit includes a single-chip microcomputer, a first motor drive circuit, a pulsating current acquisition circuit and an average current acquisition circuit. The positive pole of the first motor is electrically connected to a sampling resistor, and the other end of the sampling resistor is electrically connected to the single-chip microcomputer through the first motor drive circuit. The pulsating current acquisition circuit and the average current acquisition circuit are connected in parallel between the positive pole of the first motor and the sampling resistor, and the output end of the pulsating current acquisition circuit and the output end of the average current acquisition circuit are both electrically connected to the single-chip microcomputer; the pulsating current acquisition circuit includes a programmable gain amplifier, and the output end of the average current acquisition circuit is also electrically connected to the programmable gain amplifier.

[0006] Preferably, the first motor drive circuit includes a first motor control circuit and a first power tube, the first motor control circuit is electrically connected to a single-chip microcomputer, the gate of the first power tube is electrically connected to the output end of the first motor control circuit, the emitter of the first power tube is electrically connected to a sampling resistor, and a resistor and a capacitor are also electrically connected between the collector and emitter of the first power tube.

[0007] Preferably, the first motor drive circuit also includes a motor protection circuit, which includes a filter resistor, a third capacitor and two freewheeling fast recovery diodes, one end of the filter resistor and the third capacitor are connected in parallel to the negative electrode of the first motor, the other end of the filter resistor and the third capacitor are connected in parallel to the positive electrode of the first motor, the positive electrodes of the two freewheeling fast recovery diodes are electrically connected to the negative electrode of the first motor, and the negative electrodes of the two freewheeling fast recovery diodes are electrically connected to the positive electrode of the first motor through a sampling resistor.

[0008] Preferably, the pulsating current acquisition circuit also includes a first resistor and a first analog-to-digital converter, the first resistor is electrically connected between the sampling resistor and the positive pole of the first motor, and the other end of the first resistor is electrically connected to the programmable gain amplifier, the output end of the programmable gain amplifier is electrically connected to the first analog-to-digital converter, and the first analog-to-digital converter is electrically connected to the input end of the microcontroller.

[0009] Preferably, the average current acquisition circuit includes a second resistor, a third resistor, a first capacitor, a first amplifier and a second analog-to-digital converter connected in sequence, one end of the second resistor is electrically connected between the sampling resistor and the positive pole of the first motor, and the second analog-to-digital converter is electrically connected to the input end of the microcontroller and the programmable gain amplifier.

[0010] Preferably, the safety control circuit also includes a voltage comparison circuit, which includes a comparator, a fourth resistor, a fifth resistor, and a variable resistor. The fourth resistor is electrically connected to the output end of the first amplifier and the input end of the comparator, the common end of the fifth resistor and the variable resistor is electrically connected to the other input end of the comparator, and the other end of the variable resistor is grounded. The output end of the comparator is electrically connected to the relay drive circuit, the relay drive circuit is electrically connected to the coil of the relay, and the normally open contact of the relay is electrically connected between the power supply circuit and the AC input end of the rectifier bridge.

[0011] Preferably, the safety control circuit also includes a voltage acquisition circuit, which includes a sixth resistor, a seventh resistor, a second capacitor, a voltage zener diode and a third analog-to-digital converter, the third analog-to-digital converter is electrically connected to the input end of the single-chip microcomputer, one end of the sixth resistor is electrically connected to the third analog-to-digital converter and the other end is electrically connected to the negative electrode of the first motor, one end of the second capacitor, the seventh resistor and the voltage zener diode are connected in parallel between the sixth resistor and the third analog-to-digital converter, and the other ends of the second capacitor, the seventh resistor and the voltage zener diode are all grounded.

[0012] The utility model also provides a treadmill, comprising the above-mentioned safety control circuit.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] The utility model connects a sampling resistor to the positive pole of the first motor and connects a pulsating current acquisition circuit and an average current acquisition circuit in parallel between the positive pole of the first motor and the sampling resistor. The output end of the average current acquisition circuit is connected to a single-chip microcomputer and a programmable gain amplifier in the pulsating current acquisition circuit. The average current data acquisition circuit automatically adjusts the gain of its pulsating current data acquisition circuit to ensure accurate acquisition of pulsating current data of the footsteps touching the ground, monitors the running performance status in real time, and timely adjusts the running belt speed in an abnormal state until it stops, so as to achieve the safety of executing the running exercise plan.

[0015] The average current acquisition circuit of the utility model acquires and converts the average current data of the first motor, and transmits it to the control input end of the programmable gain amplifier and the input end of the single-chip microcomputer: when the average current data is large, the gain of the programmable gain amplifier is automatically reduced; when the average current data is small, the gain of the programmable gain amplifier is automatically increased. In this way, by automatically raising and lowering the gain of the programmable gain amplifier, the voltage drop generated by the collected pulsating current of the first motor is amplified in the linear range of the programmable gain amplifier, reflecting the pulsating current trend of the user's footsteps on the treadmill with high fidelity, and converting it into pulsating current data through the first analog-to-digital converter and inputting it into the single-chip microcomputer. The single-chip microcomputer combines the pulsating current data and the average current data to obtain the real-time ground contact time, impact force peak, step frequency, flight time and other dynamic parameters of the alternating left and right foot steps. When the difference in real-time parameters between the running left foot and the right foot exceeds a preset threshold, it is determined to be an abnormal step. When the accumulated number of abnormal steps exceeds a preset value, it is determined to be an abnormal running state, that is, the user's physical fitness is not able to keep up with the running rhythm of the treadmill. At this time, the speed of the first motor of the treadmill is reduced to ensure that the user is in a safe exercise state. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the general diagram of the safety control circuit of the utility model.

[0017] Figure 2 This is a circuit diagram of the first motor drive circuit of the utility model.

[0018] Figure 3 The utility model is a circuit diagram of a pulsating current collection circuit.

[0019] Figure 4 The utility model is a circuit diagram of an average current acquisition circuit and a voltage comparison circuit.

[0020] Figure 5 The utility model is a circuit diagram of a voltage acquisition circuit.

[0021] Figure 6 The utility model is a circuit diagram of a relay driving circuit.

[0022] Markings in the figure: 100, first motor; 10, single chip microcomputer; 11, rectifier bridge; 12, interface circuit; 21, sampling resistor; 22, first power tube; 23, first motor control circuit; 24, resistor; 25, capacitor; 26, filter resistor; 27, third capacitor; 28, freewheeling fast recovery diode; 31, first resistor; 32, programmable gain amplifier; 33, first analog-to-digital converter; 41, second resistor; 42, third resistor; 43, first capacitor; 44, first amplifier; 45. second analog-to-digital converter; 51. comparator; 52. fourth resistor; 53. fifth resistor; 54. variable resistor; 55. relay drive circuit; 56. relay; 61. sixth resistor; 62. seventh resistor; 63. second capacitor; 64. voltage stabilizing diode; 65. third analog-to-digital converter; 71. eighth resistor; 72. ninth resistor; 73. tenth resistor; 74. eleventh resistor; 75. first transistor; 76. second transistor; 77. third transistor; 78. optocoupler. DETAILED DESCRIPTION

[0023] In order to make the above features and advantages of the present invention more obvious and understandable, embodiments are given below with reference to the accompanying drawings for detailed description as follows.

[0024] like Figure 1-Figure 5 As shown, this embodiment provides a treadmill safety control circuit for controlling a first motor 100 that drives a treadmill running belt. The safety control circuit includes a single-chip microcomputer 10, a first motor driving circuit, a pulsating current acquisition circuit, and an average current acquisition circuit. The positive pole of the first motor 100 is electrically connected to a sampling resistor 21, and the other end of the sampling resistor 21 is electrically connected to the single-chip microcomputer 10 through the first motor driving circuit. The pulsating current acquisition circuit and the average current acquisition circuit are connected in parallel between the positive pole of the first motor 100 and the sampling resistor 21, and the output end of the pulsating current acquisition circuit and the output end of the average current acquisition circuit are both electrically connected to the single-chip microcomputer 10.

[0025] The single-chip microcomputer 10 of the present embodiment has a built-in program storage medium, and the program storage medium includes a safety control software module, a first motor control software module, an operation software module and an exception handling module. The single-chip microcomputer 10 collects the pulsating current data of the first motor 100 through a pulsating current acquisition circuit and collects the average current data of the first motor 100 through an average current acquisition circuit, and then uses the built-in operation software module of the single-chip microcomputer 10 to process the pulsating current data and the average current data to obtain running posture dynamic parameters such as the real-time ground contact time, impact force peak, step frequency, and flight time of alternating left and right foot steps, as well as average running posture parameters and average current data.

[0026] In this embodiment, the first motor drive circuit includes a first motor control circuit 23 and a first power tube 22, the first motor control circuit 23 is electrically connected to the output end of the single-chip microcomputer 10, the collector of the first power tube 22 is electrically connected to the positive output end of the rectifier bridge 11, the gate of the first power tube 22 is electrically connected to the output end of the first motor control circuit 23, the emitter of the first power tube 22 is electrically connected to the sampling resistor 21, and a resistor 24 and a capacitor 25 are also electrically connected between the collector and the emitter of the first power tube 22, and the negative electrode of the first motor 100 is electrically connected to the negative output end of the rectifier bridge 11, so that the single-chip microcomputer 10 drives and adjusts the speed of the first motor 100 through the first motor drive circuit. In addition, an electrolytic capacitor is also electrically connected between the positive output end and the negative output end of the rectifier bridge 11 for power supply filtering.

[0027] In this embodiment, the first motor control circuit 23 can control the speed by using the conventional pulse width modulation PWM method. The first motor drive circuit also includes a motor protection circuit, which includes a filter resistor 26, a third capacitor 27 and two freewheeling fast recovery diodes 28. One end of the filter resistor 26 and the third capacitor 27 are connected in parallel to the negative electrode of the first motor 100, and the other end of the filter resistor 26 and the third capacitor 27 are connected in parallel to the positive electrode of the first motor 100. The positive electrodes of the two freewheeling fast recovery diodes 28 are electrically connected to the negative electrode of the first motor 100, and the negative electrodes of the two freewheeling fast recovery diodes 28 are electrically connected to the positive electrode of the first motor 100 through the sampling resistor 21. Since the first power tube 22 of the first motor drive circuit is in a closed state when the pulse width modulation PWM power supply is a voltage-free output cycle, the first motor 100 as an inductive load will generate a back electromotive force voltage, and its inductive current will be freewheeled through the two freewheeling fast recovery diodes 28, thereby protecting the first power tube 22 from damage caused by the back electromotive force voltage impact, and ensuring the first motor 100 to run at a stable speed.

[0028] In this embodiment, the pulsating current acquisition circuit includes a first resistor 31, a programmable gain amplifier 32 and a first analog-to-digital converter 33, wherein the first resistor 31 is electrically connected between the sampling resistor 21 and the positive electrode of the first motor 100, and the other end of the first resistor 31 is electrically connected to the programmable gain amplifier 32, the output end of the programmable gain amplifier 32 is electrically connected to the first analog-to-digital converter 33, and the first analog-to-digital converter 33 is electrically connected to the input end of the single-chip computer 10. The average current acquisition circuit includes a second resistor 41, a third resistor 42, a first capacitor 43, a first amplifier 44 and a second analog-to-digital converter 45 connected in sequence, wherein one end of the second resistor 41 is electrically connected between the sampling resistor 21 and the positive electrode of the first motor 100, and the second analog-to-digital converter 45 is electrically connected to the input end of the single-chip computer 10 and the programmable gain amplifier 32. The output end of the second analog-to-digital converter 45 is the output end of the average current acquisition circuit, and the output end of the first analog-to-digital converter 33 is the output end of the pulsating current acquisition circuit. It should be noted that the first analog-to-digital converter 33 , the second analog-to-digital converter 45 and the programmable gain amplifier 32 may be built into the single-chip microcomputer 10 , or may be externally disposed outside the single-chip microcomputer 10 .

[0029] The average current acquisition circuit acquires and converts the average current data of the first motor 100 , and transmits the average current data to the control input terminal of the programmable gain amplifier 32 and the input terminal of the single chip microcomputer 10 . When the average current data is large, the gain of the programmable gain amplifier 32 is automatically reduced; when the average current data is small, the gain of the programmable gain amplifier 32 is automatically increased; in this way, by automatically raising and lowering the gain of the programmable gain amplifier 32, the voltage drop generated by the collected pulsating current of the first motor 100 is amplified in the linear range of the programmable gain amplifier 32, and the pulsating current trend of the user's footsteps on the treadmill is reflected with high fidelity, and is converted into pulsating current data through the first analog-to-digital converter 33 and input into the single-chip microcomputer 10. The built-in calculation software module of the single-chip microcomputer 10 processes the pulsating current data and the average current data, and obtains the real-time ground contact time, impact force peak, step frequency, flight time and other running posture dynamic parameters of the alternating left and right feet, as well as the average running posture parameters and average current data, and sends the relevant parameter data to the console through the interface circuit 12 electrically connected to the single-chip microcomputer 10.

[0030] When the difference in real-time parameters between the left and right feet exceeds a preset threshold, it is determined as an abnormal step. When the accumulated number of abnormal steps exceeds a preset value, it is determined as an abnormal running state, that is, the user's physical fitness is not up to par with the running rhythm of the treadmill. At this time, the built-in exception handling program module of the single-chip microcomputer 10 works to reduce the rotation speed of the first motor 100 of the treadmill, thereby ensuring that the user is in a safe exercise state, and sends an alarm message to the upper console through the interface circuit 12.

[0031] In addition, the safety control circuit also includes a voltage comparison circuit, which includes a comparator 51, a fourth resistor 52, a fifth resistor 53, and a variable resistor 54. The fourth resistor 52 is electrically connected to the output end of the first amplifier 44 and the input end of the comparator 51, the common end of the fifth resistor 53 and the variable resistor 54 is electrically connected to the other input end of the comparator 51, and the other end of the variable resistor 54 is grounded. The output end of the comparator 51 is electrically connected to the relay drive circuit 55, and the relay drive circuit 55 is electrically connected to the coil of the relay 56. The normally open contact of the relay 56 is electrically connected between the AC2 end of the power supply circuit and the AC input end of the rectifier bridge 11, and the other AC input end of the rectifier bridge 11 is connected to the AC1 end of the power supply circuit through a fuse. When the average current exceeds the limit, the voltage output by the first amplifier 44 exceeds the threshold, and the reverse potential at the output end of the comparator 51 triggers the relay drive circuit 55, turning off the relay 56, thereby cutting off the power supply of the first motor 100 to prevent the first power tube 22 of the first motor drive circuit from overcurrent, overheating, burning out and short-circuiting, thereby avoiding the short-circuit causing the first motor 100 to speed too fast and cause the user to fall.

[0032] The relay drive circuit 55 includes an eighth resistor 71, a ninth resistor 72, a tenth resistor 73, an eleventh resistor 74, a first transistor 75, a second transistor 76, a third transistor 77 and an optocoupler 78. The output end of the comparator 51 is connected to the base of the first transistor 75 through the eighth resistor 71, the collector of the first transistor 75 is connected to the positive input end of the optocoupler 78, and the emitter of the first transistor 75 is connected to the ninth resistor 72; the single chip computer 10 is connected to the base of the first transistor 75 through the tenth resistor 73 is connected to the base of the second transistor 76, the collector of the second transistor 76 is connected to the negative input terminal of the optocoupler 78 and the emitter of the second transistor 76 is grounded; the emitter of the output terminal of the optocoupler 78 is connected to the base of the third transistor 77 through the eleventh resistor 74, the emitter of the third transistor 77 is grounded and the collector of the third transistor 77 is connected to one end of the coil of the relay 56, and the other end of the coil of the relay 56 is connected to the collector of the output terminal of the optocoupler 78, as shown in FIG. Figure 6 As shown, relay 56 is initially closed when the treadmill is started normally, and is disconnected when the treadmill is shut down or the average current exceeds the limit.

[0033] Further, the safety control circuit also includes a voltage acquisition circuit, the voltage acquisition circuit includes a sixth resistor 61, a seventh resistor 62, a second capacitor 63, a voltage zener diode 64 and a third analog-to-digital converter 65, the third analog-to-digital converter 65 is electrically connected to the input end of the single-chip microcomputer 10, one end of the sixth resistor 61 is electrically connected to the third analog-to-digital converter 65 and the other end is electrically connected to the negative electrode of the first motor 100, the second capacitor 63, the seventh resistor 62 and one end of the voltage zener diode 64 are connected in parallel between the sixth resistor 61 and the third analog-to-digital converter 65, and the other ends of the second capacitor 63, the seventh resistor 62 and the voltage zener diode 64 are all grounded. In this embodiment, the real-time voltage of the first motor 100 is acquired by the voltage acquisition circuit, and converted into the voltage data of the first motor 100 by the third analog-to-digital converter built in the single-chip microcomputer 10, and the calculation software module built in the single-chip microcomputer 10 combines the voltage data and average current data of the first motor 100 to calculate the real-time speed of the first motor 100, so as to monitor the running state of the first motor 100 as a safety control auxiliary factor.

[0034] The above shows and describes the basic principles, main features and advantages of the invention. Those skilled in the art should understand that the invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the invention. Without departing from the spirit and scope of the invention, the invention may have various changes and improvements, which shall fall within the scope of the invention to be protected. The scope of protection of the invention shall be defined by the attached claims and their equivalents.

Claims

1. Treadmill safety control circuit, used to control the first motor that drives the treadmill running belt, Features: The safety control circuit includes a single-chip microcomputer, a first motor drive circuit, a pulsating current acquisition circuit and an average current acquisition circuit. The positive pole of the first motor is electrically connected to a sampling resistor, and the other end of the sampling resistor is electrically connected to the single-chip microcomputer through the first motor drive circuit. The pulsating current acquisition circuit and the average current acquisition circuit are connected in parallel between the positive pole of the first motor and the sampling resistor, and the output end of the pulsating current acquisition circuit and the output end of the average current acquisition circuit are both electrically connected to the single-chip microcomputer; the pulsating current acquisition circuit includes a programmable gain amplifier, and the output end of the average current acquisition circuit is also electrically connected to the programmable gain amplifier.

2. The treadmill safety control circuit according to claim 1, Features: The first motor drive circuit includes a first motor control circuit and a first power tube. The first motor control circuit is electrically connected to a single-chip microcomputer. The gate of the first power tube is electrically connected to the output end of the first motor control circuit. The emitter of the first power tube is electrically connected to a sampling resistor. A resistor and a capacitor are also electrically connected between the collector and emitter of the first power tube.

3. The treadmill safety control circuit according to claim 2, Features: The first motor drive circuit also includes a motor protection circuit, which includes a filter resistor, a third capacitor and two freewheeling fast recovery diodes, one end of the filter resistor and the third capacitor are connected in parallel to the negative electrode of the first motor, the other end of the filter resistor and the third capacitor are connected in parallel to the positive electrode of the first motor, the positive electrodes of the two freewheeling fast recovery diodes are electrically connected to the negative electrode of the first motor, and the negative electrodes of the two freewheeling fast recovery diodes are electrically connected to the positive electrode of the first motor through a sampling resistor.

4. The treadmill safety control circuit according to claim 1, Features: The pulsating current acquisition circuit also includes a first resistor and a first analog-to-digital converter. The first resistor is electrically connected between the sampling resistor and the positive pole of the first motor, and the other end of the first resistor is electrically connected to the programmable gain amplifier. The output end of the programmable gain amplifier is electrically connected to the first analog-to-digital converter, and the first analog-to-digital converter is electrically connected to the input end of the microcontroller.

5. The treadmill safety control circuit according to claim 4, Features: The first analog-to-digital converter is built into the single-chip microcomputer or is externally arranged outside the single-chip microcomputer.

6. The treadmill safety control circuit according to claim 1, Features: The average current acquisition circuit includes a second resistor, a third resistor, a first capacitor, a first amplifier and a second analog-to-digital converter connected in sequence, one end of the second resistor is electrically connected between the sampling resistor and the positive pole of the first motor, and the second analog-to-digital converter is electrically connected to the input end of the single-chip microcomputer and the programmable gain amplifier.

7. The treadmill safety control circuit according to claim 6, Features: The second analog-to-digital converter is built in the single-chip microcomputer or is externally arranged outside the single-chip microcomputer.

8. The treadmill safety control circuit according to claim 6, Features: The safety control circuit also includes a voltage comparison circuit, which includes a comparator, a fourth resistor, a fifth resistor, and a variable resistor. The fourth resistor is electrically connected to the output end of the first amplifier and the input end of the comparator, the common end of the fifth resistor and the variable resistor is electrically connected to the other input end of the comparator, and the other end of the variable resistor is grounded. The output end of the comparator is electrically connected to the relay drive circuit, the relay drive circuit is electrically connected to the coil of the relay, and the normally open contact of the relay is electrically connected between the power supply circuit and the AC input end of the rectifier bridge.

9. The treadmill safety control circuit according to claim 1, Features: The safety control circuit also includes a voltage acquisition circuit, which includes a sixth resistor, a seventh resistor, a second capacitor, a voltage zener diode and a third analog-to-digital converter. The third analog-to-digital converter is electrically connected to the input end of the single-chip microcomputer, one end of the sixth resistor is electrically connected to the third analog-to-digital converter and the other end is electrically connected to the negative electrode of the first motor, one end of the second capacitor, the seventh resistor and the voltage zener diode are connected in parallel between the sixth resistor and the third analog-to-digital converter, and the other ends of the second capacitor, the seventh resistor and the voltage zener diode are all grounded.

10. Treadmill, Features: Comprising the safety control circuit as claimed in any one of claims 1 to 9.

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