Treadmill safety control method

Abstract

The application relates to the technical field of treadmill control, and particularly discloses a safety control method for a treadmill, which comprises the following steps: during running, a lower computer of the treadmill interacts with an upper computer and executes a running program; the lower computer collects three-dimensional acceleration data in running and pulse current data and average current data of a motor of a running belt, calculates and judges running posture dynamic parameters of left and right feet of a user, and interacts with the upper computer; when a real-time parameter difference of the left and right feet of the user exceeds a preset threshold, it is determined that the steps are abnormal; when the number of accumulated abnormal steps exceeds a preset value, it is determined that the running state is abnormal; the lower computer reduces the speed of the motor of the running belt and sends an alarm message to the upper computer. The application can detect the overall performance of the body state of the user in real time, control the running drive of the treadmill in the running program execution process, ensure the exercise effect, and maximize the exercise safety.

Description

Technical Field

[0001] This invention relates to the field of treadmill control technology, and more specifically to a treadmill safety control method. Background Technology

[0002] Electric treadmills, as a type of aerobic fitness equipment unaffected by weather and allowing for convenient control of exercise intensity through speed and incline adjustments, are increasingly entering homes to meet the needs of home fitness. However, as a type of fitness equipment that involves passive exercise, electric treadmills pose certain safety risks, especially in a home environment. Without a professional coach to assess and guide exercise intensity and monitor the running process, situations such as excessive or insufficient exercise intensity, incorrect running posture, or poor physical condition often occur, leading to poor exercise results or sports injuries. Although some publicly available technologies pre-assess exercise capabilities and create running plans, automatically adjusting running speed and incline through heart rate monitoring to address the issue of exercise intensity control, these technologies are one-sided. This is because exercise heart rate only reflects the body's internal response to exercise intensity, not a comprehensive feedback of the body's overall condition. There are certain risks involved in the automatic adjustment of exercise intensity during the assessment process or when executing an exercise plan. Summary of the Invention

[0003] The purpose of this invention is to provide a treadmill safety control method that can detect the overall performance of the user's physical condition in real time, control the operation of the treadmill during the execution of the running program, and ensure exercise effectiveness while maximizing exercise safety.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] Treadmill safety control methods include:

[0006] During running, the lower-level treadmill interacts with the upper-level treadmill and executes the running program. The lower-level treadmill collects three-dimensional acceleration data, as well as pulsating current data and average current data of the running belt motor, to calculate and judge the dynamic parameters of the user's left and right foot running posture and exchange them with the upper-level treadmill.

[0007] When the real-time parameter difference between the user's left and right feet exceeds the preset threshold, it is determined to be an abnormal step. When the cumulative number of abnormal steps exceeds the preset value, it is determined to be an abnormal running state. The lower-level machine reduces the speed of the running belt motor and sends an alarm message to the upper-level machine.

[0008] Furthermore, during running, the treadmill's host computer acquires running-related body status data input from external devices, including one or more of the following: heart rate, body temperature, blood oxygen saturation, dynamic blood pressure, and electrocardiogram.

[0009] Furthermore, the lower-level machine is connected to a pulsating current acquisition circuit and an average current acquisition circuit. The pulsating current data is input to the lower-level machine through the pulsating current acquisition circuit, and the average current data is input to the lower-level machine through the average current acquisition circuit. The average current acquisition circuit automatically adjusts the gain of the pulsating current acquisition circuit to ensure accurate acquisition of the pulsating current data of the footsteps touching the ground.

[0010] Preferably, the positive terminal of the treadmill motor is electrically connected to a sampling resistor, and the pulsating current acquisition circuit and the average current acquisition circuit are connected in parallel between the positive terminal of the treadmill motor and the sampling resistor. The pulsating current acquisition circuit includes a first resistor, a programmable gain amplifier, and a first analog-to-digital converter. The first resistor is electrically connected between the sampling resistor and the positive terminal of the treadmill motor, and the other end of the first resistor is electrically connected to the programmable gain amplifier. The output terminal 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 terminal of the lower-level machine. 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 terminal of the treadmill motor, and the second analog-to-digital converter is electrically connected to the input terminal of the lower-level machine and the programmable gain amplifier.

[0011] Furthermore, the lower-level machine is also connected to a voltage comparison circuit. When the average current data exceeds a threshold during running, the power supply is automatically disconnected through the voltage comparison circuit to stop the running belt motor.

[0012] Preferably, the voltage comparison circuit includes a comparator, a fourth resistor, a fifth resistor, and a variable resistor. The fourth resistor is electrically connected to the output terminal of the first amplifier and the input terminal of the comparator. The common terminal of the fifth resistor and the variable resistor is electrically connected to the other input terminal of the comparator. The other end of the variable resistor is grounded. The output terminal of the comparator is electrically connected to a relay drive circuit. The relay drive circuit is electrically connected to the coil of the relay. The normally open contact of the relay is electrically connected between the power supply circuit and the AC input terminal of the rectifier bridge.

[0013] Furthermore, the lower-level machine is also connected to a voltage acquisition circuit. During running, the voltage acquisition circuit acquires the real-time voltage of the treadmill motor. The lower-level machine combines the voltage data and average current data of the treadmill motor to calculate the real-time speed of the treadmill motor, thereby monitoring the operating status of the treadmill motor.

[0014] Furthermore, the positive and negative terminals of the treadmill motor are connected to a diode freewheeling circuit, which ensures the stable speed operation of the treadmill motor.

[0015] Preferably, the running posture dynamic parameters include the real-time ground contact duration of alternating left and right feet, peak impact force, cadence, and airtime. The method for calculating the running posture dynamic parameters by the lower-level computer is as follows:

[0016] When the pulsating current data exceeds the average current data after the n1th step falls, timing Tn1.0 and counting Cn begin. When the pulsating current data reaches its peak value after the step falls, timing Tn1.1 begins. When both feet leave the ground, the pulsating current data decreases to its trough value, timing Tn1.2 begins. The peak pulsating current data is proportionally calculated with a preset constant to obtain the peak impact force Pn1.

[0017] When the pulsating current data exceeds the average current data after the n2th step falls, timing Tn2.0 and counting Cn+1 begin. When the pulsating current data reaches its peak value during the step fall, timing Tn2.1 begins. When both feet leave the ground, the pulsating current data decreases to its trough value, timing Tn2.2 begins. The peak pulsating current data is proportionally calculated with a preset constant to obtain the peak impact force Pn2.

[0018] When the pulsating current data exceeds the average current data after the n3rd step, timing Tn3.0 and counting Cn+2 begin. When the pulsating current data reaches its peak value during the step, timing Tn3.1 begins. When both feet leave the ground, the pulsating current data decreases to its trough value, timing Tn3.2 begins. The peak pulsating current data is proportionally calculated with a preset constant to obtain the peak impact force Pn3.

[0019] Calculation of ground contact time per step:

[0020] The duration of foot n1's contact with the ground = Tn1.1 - Tn1.0

[0021] The duration of foot n2's contact with the ground = Tn2.2 - Tn2.0

[0022] The duration of foot n3's contact with the ground = Tn3.2 - Tn3.0

[0023] The duration of foot n's contact with the ground = Tni.2 - Tni.0

[0024] Average ground contact time = (ground contact time of the n1st foot + ground contact time of the n2nd foot + ground contact time of the n3rd foot + ... + ground contact time of the nith foot) / i;

[0025] Calculation of airtime for each step:

[0026] The duration of the n2th foot in the air = Tn2.0 - Tn1.2

[0027] The duration of the n3rd foot in the air = Tn3.0 - Tn2.2

[0028] The duration of the n4th foot in the air = Tn4.0 - Tn3.2

[0029] The (ni+1)th foot's time in the air = Tni+1.0 - Tni.2

[0030] Average flight time = (flight time of the n2nd foot + flight time of the n3rd foot + flight time of the n4th foot + ... + flight time of the ni+1th foot) / i;

[0031] Step frequency calculation: Step frequency = (count Cn+i) / (Tni.0–Tn1.0).

[0032] Furthermore, the safety control method also includes: before running, the treadmill's host computer collects the user's basic exercise and health data and automatically generates a running program.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] This invention utilizes a lower-level computer to collect pulsating current and average current data of the treadmill belt motor during running, and combines this with three-dimensional acceleration data analysis to obtain dynamic parameters of the running posture of the left and right feet, thereby monitoring running performance in real time. Simultaneously, the upper-level computer combines the user's real-time physical status information to comprehensively control the operation and drive of the treadmill during aerobic running ability assessment and personalized running program execution. In abnormal states, the exercise intensity is adjusted in a timely manner, and in extreme abnormal situations, the treadmill belt speed is gradually reduced until it stops, thereby ensuring the safety of executing aerobic running ability assessment and personalized running exercise programs.

[0035] This invention connects a sampling resistor to the positive terminal of the treadmill motor, and connects a pulsating current acquisition circuit and an average current acquisition circuit in parallel between the positive terminal of the treadmill motor and the sampling resistor. The output of the average current acquisition circuit is connected to the lower-level computer and the 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 the pulsating current data of the footsteps touching the ground, monitors the running performance status in real time, and adjusts the treadmill speed in time until it stops in abnormal conditions, so as to achieve the safety of executing the running exercise plan.

[0036] The average current acquisition circuit of the present invention acquires and converts the average current data of the treadmill motor, and sends it to the control input terminal of the programmable gain amplifier and the input terminal of the lower-level machine: when the average current data is large, the gain of the programmable gain amplifier automatically decreases; when the average current data is small, the gain of the programmable gain amplifier automatically increases. By automatically adjusting the gain of the programmable gain amplifier, the voltage drop generated by the pulsating current of the treadmill motor is amplified within the linear range of the programmable gain amplifier, thus faithfully reflecting the pulsating current trend of the user's footsteps on the treadmill. This data is then converted into pulsating current data by the first analog-to-digital converter and input to the lower-level machine. The lower-level machine combines the pulsating current data and the average current data to obtain dynamic running posture parameters such as the real-time ground contact time, peak impact force, cadence, and airtime of the alternating left and right feet. When the real-time parameter difference between the left and right feet exceeds a preset threshold, it is determined to be an abnormal footstep. When the cumulative number of abnormal feet exceeds a preset value, it is determined to be an abnormal running state, i.e., the user's physical fitness is not keeping up with the treadmill's pace. At this time, the speed of the treadmill motor is reduced and the speed / incline parameters of the running program are updated to ensure the user is in a safe exercise state. Attached Figure Description

[0037] Figure 1 This is a circuit diagram of the safety control circuit and the lower-level machine of the present invention.

[0038] Figure 2 This is a circuit diagram of the treadmill motor drive circuit of the present invention.

[0039] Figure 3 This is a circuit diagram of the pulsating current acquisition circuit of the present invention.

[0040] Figure 4 This is a circuit diagram of the average current acquisition circuit and voltage comparison circuit of the present invention.

[0041] Figure 5 This is a circuit diagram of the voltage acquisition circuit of the present invention.

[0042] Figure 6 This is a circuit diagram of the relay driving circuit of the present invention.

[0043] Figure 7 This is a schematic diagram of the treadmill safety control method of the present invention.

[0044] In the diagram, the markings are as follows: 100, treadmill belt motor; 200, incline adjustment motor; 10, lower-level machine; 11, rectifier bridge; 12, lower interface circuit; 13, three-dimensional acceleration sensor module; 14, incline adjustment motor drive circuit; 21, sampling resistor; 22, first power transistor; 23, treadmill belt 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, the... 43. First resistor; 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. Zener 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 Implementation

[0045] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation.

[0046] like Figure 7 As shown, this embodiment provides a safety control method for a treadmill. The treadmill includes an upper computer and a lower computer 10. The safety control method includes: before running, the upper computer collects the user's basic exercise and health data and automatically generates a running program; during running, the lower computer 10 interacts with the upper computer and executes the running program. The lower computer 10 collects three-dimensional acceleration data and pulsating current data and average current data of the running belt motor 100 to calculate and judge the dynamic parameters of the user's left and right foot running posture and exchanges them with the upper computer; when the real-time parameter difference between the user's left and right feet exceeds a preset threshold, it is determined to be an abnormal step; when the cumulative number of abnormal steps exceeds a preset value, it is determined to be an abnormal running state. The lower computer 10 reduces the speed of the running belt motor 100 and sends an alarm message to the upper computer; after receiving the alarm message, the upper computer updates the running program, reduces the speed and / or incline parameters to adjust the exercise intensity, and the lower computer 10 then executes the updated running program. If the user still cannot keep up with the running program, the program is cyclically adjusted and gradually reduced in speed until the machine stops.

[0047] The host computer is connected to a touch control circuit, a display circuit, a voice broadcast circuit, an external communication circuit, and an upper interface circuit. During running, the host computer connects to external devices such as heart rate monitoring devices and electrocardiogram monitoring devices through the external communication circuit and acquires body status data input from these devices, such as heart rate, body temperature, blood oxygen saturation, dynamic blood pressure, and electrocardiogram. The lower computer 10 has a built-in program storage medium, which includes a safety control software module, a treadmill belt motor control software module, an incline adjustment motor control software module, a calculation software module, and an exception handling module. The lower computer 10 is also connected to a power supply circuit, a safety control circuit, a lower interface circuit 12, an incline adjustment motor drive circuit 14, and a three-dimensional acceleration sensor module 13.

[0048] The host computer interacts with the user through display circuits, touch circuits, and voice playback circuits to acquire basic sports and health data, including basic user information (such as gender, age, height, weight, etc.), exercise history data, physical condition data, and exercise goal data. When the user selects an aerobic running ability test, the treadmill executes an aerobic running ability program. The host computer calculates the maximum oxygen uptake (VO2 max) based on the user's basic information and test results. Combining the user's VO2 max, physical condition information, exercise history information, and exercise goal information, the host computer generates a personalized running program for the user. The speed of the running belt motor 100 and the incline of the incline adjustment motor 200 are used to change the exercise intensity at each stage of the running program. The host computer, in conjunction with the user's real-time physical condition information, collaborates with the safety control circuits and methods of the lower-level computer 10 to evaluate the user's internal and external physical condition, playing a crucial role throughout the running exercise process to ensure user safety.

[0049] Specifically, such as Figures 1-6 As shown, the safety control circuit includes a treadmill motor drive circuit, a pulsating current acquisition circuit, an average current acquisition circuit, a voltage comparison circuit, a voltage acquisition circuit, and a diode freewheeling circuit. The positive terminal of the treadmill motor 100 is electrically connected to a sampling resistor 21. The pulsating current acquisition circuit and the average current acquisition circuit are connected in parallel between the positive terminal of the treadmill motor 100 and the sampling resistor 21.

[0050] The treadmill motor drive circuit includes a treadmill motor control circuit 23 and a first power transistor 22. The treadmill motor control circuit 23 is electrically connected to the output terminal of the lower-level machine 10. The treadmill motor control circuit 23 can control the speed using the conventional pulse width modulation (PWM) method. The collector of the first power transistor 22 is electrically connected to the positive output terminal of the rectifier bridge 11, the gate of the first power transistor 22 is electrically connected to the output terminal of the treadmill motor control circuit 23, and the emitter of the first power transistor 22 is electrically connected to the sampling resistor 21. A resistor 24 and a capacitor 25 are also electrically connected between the collector and emitter of the first power transistor 22. The negative terminal of the treadmill motor 100 is electrically connected to the negative output terminal of the rectifier bridge 11. In this way, the lower-level machine 10 drives and adjusts the speed of the treadmill motor 100 through the treadmill motor drive circuit.

[0051] The diode freewheeling circuit 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 terminal of the treadmill motor 100, and the other end of the filter resistor 26 and the third capacitor 27 are connected in parallel to the positive terminal of the treadmill motor 100. The positive terminals of the two freewheeling fast recovery diodes 28 are electrically connected to the negative terminal of the treadmill motor 100, and the negative terminals of the two freewheeling fast recovery diodes 28 are electrically connected to the positive terminal of the treadmill motor 100 through a sampling resistor 21. Since the first power transistor 22 of the treadmill motor drive circuit is in the off state when the pulse width modulation (PWM) power supply is in a no-voltage output cycle, the treadmill motor 100, as an inductive load, will generate a back electromotive force (EMF) voltage. Its induced current will freewheel through the two freewheeling fast recovery diodes 28, thereby protecting the first power transistor 22 from damage caused by the back EMF voltage and ensuring the stable speed operation of the treadmill motor 100.

[0052] The pulsating current data is input to the lower-level machine 10 through the pulsating current acquisition circuit. The pulsating current acquisition circuit includes a first resistor 31, a programmable gain amplifier 32, and a first analog-to-digital converter 33. The first resistor 31 is electrically connected between the sampling resistor 21 and the positive terminal of the treadmill motor 100, and the other end of the first resistor 31 is electrically connected to the programmable gain amplifier 32. The output terminal 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 terminal of the lower-level machine 10.

[0053] The average current data is input to the lower-level machine 10 through the average current acquisition circuit. 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. One end of the second resistor 41 is electrically connected between the sampling resistor 21 and the positive terminal of the running belt motor 100. The second analog-to-digital converter 45 is electrically connected to the input terminal of the lower-level machine 10 and the programmable gain amplifier 32.

[0054] The average current acquisition circuit acquires and converts the average current data of the treadmill motor 100, and sends it to the control input terminal of the programmable gain amplifier 32 and the input terminal of the lower-level machine 10. The average current acquisition circuit automatically adjusts the gain of the pulsating current acquisition circuit to ensure accurate acquisition of the pulsating current data of the footsteps touching the ground. Specifically: when the average current data is large, the gain of the programmable gain amplifier 32 automatically decreases; when the average current data is small, the gain of the programmable gain amplifier 32 automatically increases. In this way, by automatically adjusting the gain of the programmable gain amplifier 32, the voltage drop generated by the pulsating current of the treadmill motor 100 is amplified in the linear range of the programmable gain amplifier 32, so as to reflect the pulsating current trend of the user's footsteps on the treadmill with high fidelity. The data is converted into pulsating current data by the first analog-to-digital converter 33 and input to the lower computer 10. The computing software module built into the lower computer 10 processes the pulsating current data and the average current data to obtain dynamic parameters of running posture such as the real-time ground contact time of the left and right feet, peak impact force, cadence, and airtime, as well as average running posture parameters and average current data. At the same time, the relevant parameter data is sent to the upper computer through the lower interface circuit 12 electrically connected to the lower computer 10.

[0055] The method by which the lower-level computer 10 calculates the dynamic parameters of running posture is as follows:

[0056] When the pulsating current data exceeds the average current data after the n1th step falls, timing Tn1.0 and counting Cn begin. When the pulsating current data reaches its peak value after the step falls, timing Tn1.1 begins. When both feet leave the ground, the pulsating current data decreases to its trough value, timing Tn1.2 begins. The peak pulsating current data is proportionally calculated with a preset constant to obtain the peak impact force Pn1.

[0057] When the pulsating current data exceeds the average current data after the n2th step falls, timing Tn2.0 and counting Cn+1 begin. When the pulsating current data reaches its peak value during the step fall, timing Tn2.1 begins. When both feet leave the ground, the pulsating current data decreases to its trough value, timing Tn2.2 begins. The peak pulsating current data is proportionally calculated with a preset constant to obtain the peak impact force Pn2.

[0058] When the pulsating current data exceeds the average current data after the n3rd step, timing Tn3.0 and counting Cn+2 begin. When the pulsating current data reaches its peak value during the step, timing Tn3.1 begins. When both feet leave the ground, the pulsating current data decreases to its trough value, timing Tn3.2 begins. The peak pulsating current data is proportionally calculated with a preset constant to obtain the peak impact force Pn3.

[0059] Calculation of ground contact time per step:

[0060] The duration of foot n1's contact with the ground = Tn1.1 - Tn1.0

[0061] The duration of foot n2's contact with the ground = Tn2.2 - Tn2.0

[0062] The duration of foot n3's contact with the ground = Tn3.2 - Tn3.0

[0063] The duration of foot n's contact with the ground = Tni.2 - Tni.0

[0064] Average ground contact time = (ground contact time of the n1st foot + ground contact time of the n2nd foot + ground contact time of the n3rd foot + ... + ground contact time of the nith foot) / i;

[0065] Calculation of airtime for each step:

[0066] The duration of the n2th foot in the air = Tn2.0 - Tn1.2

[0067] The duration of the n3rd foot in the air = Tn3.0 - Tn2.2

[0068] The duration of the n4th foot in the air = Tn4.0 - Tn3.2

[0069] The (ni+1)th foot's time in the air = Tni+1.0 - Tni.2

[0070] Average flight time = (flight time of the n2nd foot + flight time of the n3rd foot + flight time of the n4th foot + ... + flight time of the ni+1th foot) / i;

[0071] Step frequency calculation: Step frequency = (count Cn+i) / (Tni.0–Tn1.0).

[0072] The three-dimensional acceleration data is obtained through a three-dimensional acceleration sensor module 13, which is installed in the middle of the running platform perpendicular to the running belt direction. The three-dimensional acceleration sensor module 13 is electrically connected to the lower-level computer 10. The algorithm software module built into the lower-level computer 10 calculates and determines the left and right foot attributes of the running posture parameters based on the three-dimensional acceleration data. The upper-level computer receives the data transmitted by the lower interface circuit 12 of the lower-level computer 10 through the upper interface circuit. This includes dynamic running posture parameters such as the real-time ground contact time, peak impact force, cadence, and airtime of the left and right feet, as well as average running posture parameters. The data is displayed through text, pictures, videos, and voice, while also demonstrating the correct running posture method to guide the user in running correctly.

[0073] When the real-time parameter difference between the left and right feet exceeds a preset threshold, it is determined to be an abnormal step. When the cumulative number of abnormal steps exceeds a preset value, it is determined to be an abnormal running state, meaning the user's physical condition is not good and they cannot keep up with the treadmill's pace. At this time, the abnormal handling program module built into the lower-level machine 10 starts working, reducing the speed of the treadmill's running belt motor 100 to ensure the user's safe exercise state, and sending an alarm message to the upper-level machine through the lower interface circuit 12. After receiving the alarm message, the upper-level machine updates the running program, reducing the speed and / or incline parameters to adjust the exercise intensity and issuing sound and text prompts. The lower-level machine 10 then executes the updated running program. If the user still cannot keep up with the running program, the adjustment is repeated cyclically, gradually reducing the speed until the machine stops.

[0074] During running, when the average current data exceeds a threshold, the power supply is automatically disconnected via a voltage comparison circuit to stop the running belt motor 100. The voltage comparison circuit 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 of the first amplifier 44 and the input of the comparator 51. The common terminal of the fifth resistor 53 and the variable resistor 54 is electrically connected to the other input of the comparator 51. The other end of the variable resistor 54 is grounded. The output of the comparator 51 is electrically connected to a relay drive circuit 55. The relay drive circuit 55 can use a conventional circuit module. The relay drive circuit 55 is electrically connected to the coil of a relay 56. The normally open contact of the relay 56 is electrically connected between the AC2 terminal of the power supply circuit and the AC input terminal of the rectifier bridge 11. The other AC input terminal of the rectifier bridge 11 is connected to the AC1 terminal of the power supply circuit via a fuse. When the average current exceeds the threshold, the voltage output by the first amplifier 44 exceeds the threshold. The reverse potential at the output of the comparator 51 triggers the relay drive circuit 55 to turn off the relay 56, thereby cutting off the power supply to the treadmill motor 100. This is to prevent the first power transistor 22 of the treadmill motor drive circuit from overheating and burning out, thus avoiding the risk of the treadmill motor 100 going too fast and causing the user to fall.

[0075] 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 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 of the optocoupler 78, and the emitter of the first transistor 75 is connected to the ninth resistor 72. The microcontroller 10 is connected to 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; the other end of the coil of the relay 56 is connected to the collector of the output terminal of the optocoupler 78, as follows. Figure 6 As shown, relay 56 closes when the treadmill is running normally, and opens when the machine stops or when the average current exceeds the limit.

[0076] The voltage acquisition circuit collects the real-time voltage of the treadmill motor 100. During operation, the lower-level computer 10 combines the voltage data and average current data of the treadmill motor 100 to calculate the real-time speed of the treadmill motor 100, thereby monitoring the operating status of the treadmill motor 100 and serving as an auxiliary factor for safety control. Figure 5 As shown, the voltage acquisition circuit includes a sixth resistor 61, a seventh resistor 62, a second capacitor 63, a Zener diode 64, and a third analog-to-digital converter 65. The third analog-to-digital converter 65 is electrically connected to the input terminal of the lower-level machine 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 terminal of the running belt motor 100. One end of the second capacitor 63, the seventh resistor 62, and the Zener diode 64 are connected in parallel between the sixth resistor 61 and the third analog-to-digital converter 65. The other ends of the second capacitor 63, the seventh resistor 62, and the Zener diode 64 are all grounded.

[0077] The foregoing has shown and described the basic principles, main features and advantages of this invention. Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are only illustrative of the principles of this invention. Various changes and modifications can be made to this invention without departing from the spirit and scope of this invention. All such changes and modifications fall within the scope of this invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method of safety control of a treadmill, characterized by: The method comprises: During running, the lower computer of the treadmill interacts with the upper computer and executes according to the running program, the lower computer collects three-dimensional acceleration data in running, pulsating current data and average current data of the running belt motor, calculates and judges the running posture dynamic parameters of the left foot and the right foot of the user and interacts with the upper computer; When the real-time parameter difference of the left foot and the right foot of the user exceeds the preset threshold value, it is determined that the footstep is abnormal, and when the number of accumulated abnormal footsteps exceeds the preset value, it is determined that the running state is abnormal, the lower computer reduces the speed of the running belt motor and sends an alarm information to the upper computer; The lower computer is connected with a pulsating current collection circuit and an average current collection circuit, the pulsating current data is input into the lower computer through the pulsating current collection circuit, the average current data is input into the lower computer through the average current collection circuit, the average current collection circuit automatically adjusts the gain of the pulsating current collection circuit to ensure accurate collection of the motion footstep touchdown pulsating current data; The positive electrode of the running belt motor is electrically connected with a sampling resistor, the pulsating current collection circuit and the average current collection circuit are connected in parallel between the positive electrode of the running belt motor and the sampling resistor; the pulsating current collection circuit comprises a first resistor, a program-controlled gain amplifier and a first analog-to-digital converter, the first resistor is electrically connected between the sampling resistor and the positive electrode of the running belt motor, and the other end of the first resistor is electrically connected with the program-controlled gain amplifier, the output end of the program-controlled gain amplifier is electrically connected with the first analog-to-digital converter, and the first analog-to-digital converter is electrically connected with the input end of the lower computer; the average current collection circuit comprises 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 electrode of the running belt motor, and the second analog-to-digital converter is electrically connected with the input end of the lower computer and the program-controlled gain amplifier.

2. The method of claim 1, wherein: During running, the upper computer of the treadmill acquires the body state data in running input by the external device, and the body state data in running includes one or more of heart rate, body temperature, blood oxygen saturation, dynamic blood pressure and electrocardiogram.

3. The method of claim 1, wherein: The lower computer is also connected with a voltage comparison circuit, when the average current data exceeds the threshold value during running, the voltage comparison circuit automatically disconnects the power supply to stop the running belt motor.

4. The method of claim 3, wherein: The voltage comparison circuit comprises a comparator, a fourth resistor, a fifth resistor and a variable resistor, the fourth resistor is electrically connected with 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 with the other input end of the comparator, the other end of the variable resistor is grounded, the output end of the comparator is electrically connected with a relay driving circuit, the relay driving circuit is electrically connected with the coil of a 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.

5. The method of claim 1, wherein: The lower computer is also connected with a voltage collection circuit, the real-time voltage of the running belt motor is collected by the voltage collection circuit during running, and the lower computer calculates the real-time rotating speed of the running belt motor in combination with the voltage data and the average current data of the running belt motor to monitor the running state of the running belt motor.

6. The method of claim 1, wherein: The positive and negative poles of the running belt motor are connected with a diode freewheeling circuit, which ensures stable speed operation of the running belt motor.

7. The method of claim 1, wherein: The running posture dynamic parameters include the real-time ground contact time of the left foot and the right foot, the impact force peak value, the step frequency, and the flight time, and the method for calculating the running posture dynamic parameters by the lower computer is as follows: When the foot-falling pulse current data of the n1th step exceeds the average current data, the timing Tn1.0 and the count Cn are started, the foot-falling pulse current data reaches the peak value at the timing Tn1.1, the pulse current data decreases to the valley value at the timing Tn1.2 when the feet are off the ground, and the peak pulse current data is subjected to proportional operation with a preset constant to obtain the impact force peak value Pn1; When the foot-falling pulse current data of the n2th step exceeds the average current data, the timing Tn2.0 and the count Cn+1 are started, the foot-falling pulse current data reaches the peak value at the timing Tn2.1, the pulse current data decreases to the valley value at the timing Tn2.2 when the feet are off the ground, and the peak pulse current data is subjected to proportional operation with a preset constant to obtain the impact force peak value Pn2; When the foot-falling pulse current data of the n3th step exceeds the average current data, the timing Tn3.0 and the count Cn+2 are started, the foot-falling pulse current data reaches the peak value at the timing Tn3.1, the pulse current data decreases to the valley value at the timing Tn3.2 when the feet are off the ground, and the peak pulse current data is subjected to proportional operation with a preset constant to obtain the impact force peak value Pn3; The ground contact time of each step is calculated as follows: The ground contact time of the n1th foot = Tn1.1-Tn1.0 The ground contact time of the n2th foot = Tn2.2-Tn2.0 The ground contact time of the n3th foot = Tn3.2-Tn3.0 The ground contact time of the nthi foot = Tni.2-Tni.0 The average ground contact time = (the ground contact time of the n1th foot + the ground contact time of the n2th foot + the ground contact time of the n3th foot + … + the ground contact time of the nthi foot) / i The flight time of each step is calculated as follows: The flight time of the n2th foot = Tn2.0-Tn1.2 The flight time of the n3th foot = Tn3.0-Tn2.2 The flight time of the n4th foot = Tn4.0-Tn3.2 The flight time of the nthi+1 foot = Tni+1.0-Tni.2 The average flight time = (the flight time of the n2th foot + the flight time of the n3th foot + the flight time of the n4th foot + … + the flight time of the nthi+1 foot) / i The step frequency is calculated as follows: step frequency = (count Cn+i) / (Tni.0-Tn1.0).

8. The method of claim 1 to 7, wherein: The safety control method further includes that before running, the upper computer of the running machine collects user motion health basic data and automatically generates a running program.

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