Motor control circuit system of treadmill

Abstract

The invention discloses a treadmill motor control circuit system. The treadmill motor control circuit system comprises a main control module, a motor driving module, a phase current acquisition unit and a motor, the motor driving module comprises a three-phase driving unit and a driving control unit, the phase current acquisition unit is electrically connected with the three-phase driving unit and the main control module, the driving control unit is electrically connected with the main control module and the three-phase driving unit, and the three-phase driving unit is electrically connected with the motor; each phase driving unit of the three-phase driving unit comprises an upper bridge arm circuit and a lower bridge arm circuit. When a user exercises on the running machine, the rotating speed of the motor is changed compared with the rotating speed of the motor when the running machine is no-load, so that the phase current of the motor is changed, the main control module obtains the running speed state of the user by monitoring the phase current of the motor, and then the set duty ratio is sent to the motor driving module; the motor driving module controls the running state of the motor, the rotating speed of the motor is adjusted in real time according to different running speeds of a user, and meanwhile the use safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a treadmill motor control circuit system. Background Art

[0002] In recent years, with the enhancement of people's health awareness and the improvement of living standards, electric treadmills have gradually become popular among consumers.

[0003] The common treadmill speed adjustment methods on the market are generally the following:

[0004] 1. Multi-speed adjustment

[0005] The user can adjust the speed of the treadmill belt by selecting different gears. Although this can achieve a similar speed-changing effect, it has poor flexibility and cannot achieve real-time automatic adjustment.

[0006] 2. Timing speed regulation

[0007] The user can gradually increase or decrease the speed of the treadmill within the set time by selecting a time period and increasing or decreasing gears. The flexibility is improved, but it cannot adapt to the actual running speed changes of the user, so the experience is relatively poor.

[0008] The above speed adjustment methods cannot well meet the different running habits of users, and may also cause safety accidents due to insufficient response.

[0009] In summary, an object of the present invention is to provide a treadmill motor control circuit system that can solve at least one of the above problems. Summary of the invention

[0010] The purpose of the present invention is to provide a treadmill motor control circuit system designed to solve the deficiencies of the above-mentioned technology.

[0011] A treadmill motor control circuit system designed by the present invention comprises a main control module, a motor drive module, a phase current acquisition unit and a motor, wherein the motor drive module comprises a three-phase drive unit and a drive control unit, wherein the phase current acquisition unit is electrically connected to the three-phase drive unit and the main control module respectively, wherein the drive control unit is electrically connected to the main control module and the three-phase drive unit respectively, and wherein the three-phase drive unit is electrically connected to the motor;

[0012] Each phase drive unit of the three-phase drive unit comprises an upper bridge arm circuit and a lower bridge arm circuit, the upper bridge arm circuit comprises a first resistor, a second resistor, a first diode, and a first switch tube, and the lower bridge arm circuit comprises a third resistor, a fourth resistor, a fifth resistor, a second diode, and a second switch tube;

[0013] The anode of the first diode is electrically connected to the control electrode of the first switch tube through the first resistor, the cathode of the first diode is electrically connected to the drive control unit, the cathode of the first diode is also electrically connected to the control electrode of the first switch tube through the second resistor, the first end of the first switch tube is electrically connected to the anode of the first power supply end, and the second end of the first switch tube is electrically connected to the corresponding winding of the motor; the anode of the second diode is electrically connected to the control electrode of the second switch tube through the third resistor, the cathode of the second diode is electrically connected to the drive control unit, the cathode of the second diode is also electrically connected to the control electrode of the second switch tube through the fourth resistor, the first end of the second switch tube is electrically connected to the second end of the first switch tube, and the second end of the second switch tube is electrically connected to the ground end through the fifth resistor;

[0014] The phase current acquisition unit is electrically connected to the second end of the second switch tube of each lower bridge arm circuit, and is used to collect the motor phase current at the current moment and send it to the main control module;

[0015] The main control module is used to compare the collected phase current of the motor at the current moment with the preset current when the motor is running, obtain the corresponding set duty cycle according to the comparison result, and send the set duty cycle to the drive control unit. The drive control unit controls the running state of the motor according to the set duty cycle signal.

[0016] Furthermore, when the motor needs to perform a braking operation, the drive control unit controls the first switch tube in each upper bridge arm circuit to turn off, and the drive control unit controls the second switch tube in each lower bridge arm circuit to turn on, so that the three windings of the motor are short-circuited.

[0017] Furthermore, it also includes a total current acquisition unit for collecting the three-phase total current; one end of the total current acquisition unit is electrically connected to the drive control unit, and the other end of the total current acquisition unit is electrically connected to the second end of each of the second switch tubes through a third diode;

[0018] The drive control unit is used to determine whether the motor is overcurrent based on the total current collected by the total current collection unit at the current moment when the motor is running. If it is determined that there is overcurrent, the drive control unit feeds back the overcurrent information to the main control module, and the main control module stops outputting PWM.

[0019] Furthermore, it also includes a bootstrap circuit unit, which includes a sixth resistor, a seventh resistor, a fourth diode, a first capacitor, and a second capacitor;

[0020] The first capacitor is connected in parallel to both ends of the driving control unit, the second capacitor is connected in parallel to both ends of the first capacitor, the first end of the sixth resistor and the first end of the seventh resistor are electrically connected to the second power supply end respectively, the second end of the sixth resistor is electrically connected to the second end of the seventh resistor, the second end of the sixth resistor is electrically connected to one end of the first capacitor through a fourth diode, the other end of the first capacitor is electrically connected to the second end of the first switching tube, and each phase driving unit corresponds to a fourth diode, a first capacitor, and a second capacitor.

[0021] Furthermore, it also includes a back-EMF collection unit corresponding to each phase driving unit, and the back-EMF collection unit includes a fifth diode, an eighth resistor, and a ninth resistor;

[0022] The cathode of the fifth diode is electrically connected to one end of the second capacitor, the anode of the fifth diode is sequentially connected to the eighth resistor and the ninth resistor and then electrically connected to the corresponding winding of the motor, and the anode of the fifth diode is respectively electrically connected to the second end of the first switching tube and the first end of the second switching tube of the same phase drive unit.

[0023] Furthermore, the phase current acquisition unit includes a reference voltage generating circuit, a voltage follower circuit, three current sampling resistors, and three comparison circuits;

[0024] The input end of each current sampling resistor is electrically connected to the second end of the second switch tube of the corresponding lower bridge arm circuit, the output end of each current sampling resistor is electrically connected to the first input end of the corresponding comparison circuit, the input end of the reference voltage generating circuit is electrically connected to the third power supply end, the output end of the reference voltage generating circuit is electrically connected to the first input end of the voltage follower circuit, the output end and the second input end of the voltage follower circuit are respectively electrically connected to the second input end of the corresponding comparison circuit, the output end of each comparison circuit is electrically connected to the main control module, and the first power supply end of the comparison circuit is electrically connected to the third power supply end.

[0025] Furthermore, it also includes a power supply circuit, the power supply circuit includes a first power supply end, a second power supply end and a third power supply end; a power-on buffer unit is provided between the power supply circuit and the AC input end, and the power-on buffer unit is also connected to the main control module;

[0026] The power-on buffer unit includes a relay, a tenth resistor, a third switch tube, and a sixth diode. The movable contact of the relay is electrically connected to the AC input end through a thermistor, the movable contact of the relay is electrically connected to the power supply circuit, the first end of the relay power-on coil is electrically connected to the second power supply end through the tenth resistor, the sixth diode is connected in series between the first end and the second end of the relay power-on coil, the second end of the relay power-on coil is electrically connected to the first end of the third switch tube, the control electrode of the third switch tube is electrically connected to the main control module through the seventeenth resistor, and the second end of the third switch tube is electrically connected to the ground end.

[0027] Furthermore, a first protection resistor is provided between the control electrode of the first switch tube and the second end thereof, and a second protection resistor is provided between the control electrode of the second switch tube and the second end thereof.

[0028] Furthermore, a first filtering unit is provided between the control electrode of the first switch tube and the second end thereof, and between the control electrode of the second switch tube and the second end thereof, respectively.

[0029] A treadmill motor control circuit system designed by the present invention, when the user exercises on the treadmill, the motor speed changes compared to when the treadmill is unloaded, causing the motor phase current to change, so that the main control module obtains the user's running speed state by monitoring the motor phase current, and then sends the set duty cycle to the motor drive module, so that the motor drive module controls the running state of the motor, realizes real-time adjustment of the motor speed according to the different running speeds of the user, and at the same time improves the safety of use, can provide customized services for users, and also helps to improve the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural principle block diagram of a treadmill motor control circuit system disclosed in the present invention;

[0031] Figure 2 It is a circuit schematic diagram of the connection between the power supply circuit, the power-on buffer unit and the main control module;

[0032] Figure 3 It is the circuit schematic diagram of the phase current acquisition unit;

[0033] Figure 4 It is the circuit schematic diagram of the motor drive module, the bootstrap circuit unit, the back EMF acquisition unit, and the total current acquisition unit;

[0034] Figure 5 This is the circuit schematic diagram of the main control module.

[0035] In the figure: 1. main control module; 2. motor drive module; 21. three-phase drive unit; 22. drive control unit; 3. phase current acquisition unit; 31. voltage follower circuit; 32. current sampling circuit; 33. differential amplifier circuit; 4. motor; 5. total current acquisition unit; 6. bootstrap circuit unit; 7. back electromotive force acquisition unit; 8. power supply circuit; 9. AC input terminal; 10. power-on buffer unit; 11. first filter unit. DETAILED DESCRIPTION

[0036] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0037] Embodiment 1:

[0038] like Figure 1 , 4 As shown, a treadmill motor control circuit system described in this embodiment includes a main control module 1, a motor drive module 2, a phase current acquisition unit 3 and a motor 4. The motor drive module 2 includes a three-phase drive unit 21 and a drive control unit 22. The phase current acquisition unit 3 is electrically connected to the three-phase drive unit 21 and the main control module 1 respectively. The drive control unit 22 is electrically connected to the main control module 1 and the three-phase drive unit 21 respectively. The three-phase drive unit 21 is electrically connected to the motor 4. The main control module 1 is connected to the host computer through an optical coupling isolation circuit to achieve signal isolation, improve anti-interference ability, and isolate primary and secondary high voltages.

[0039] Each phase drive unit of the three-phase drive unit 21 includes an upper bridge arm circuit 211 and a lower bridge arm circuit 212, wherein the upper bridge arm circuit 211 includes a first resistor (R91, R95, R99), a second resistor (R92, R96, R100), a first diode (D11, D13, D15), and a first switch tube (Q5, Q7, Q9), and the lower bridge arm circuit 212 includes a third resistor (R93, R97, R101), a fourth resistor (R94, R98, R102), a fifth resistor (R112, R113, R114), a second diode (D12, D14, D15), and a second switch tube (Q6, Q8, Q10). Among them, Q5-Q10 are all IGBT tubes.

[0040] Taking the circuit connection relationship of the driving unit of the W-phase winding as an example, the positive electrode of the first diode D11 is electrically connected to the control electrode of the first switch tube Q5 through the first resistor R91, the negative electrode of the first diode D11 is electrically connected to the drive control unit 22, and the negative electrode of the first diode D11 is also electrically connected to the control electrode of the first switch tube Q5 through the second resistor R92. The first end of the first switch tube Q5 is electrically connected to the positive electrode of the first power supply end, wherein the first power supply end is V+; the second end of the first switch tube Q5 is electrically connected to the W-phase winding of the motor 4.

[0041] The anode of the second diode D12 is electrically connected to the control electrode of the second switch tube Q6 through the third resistor R93, the cathode of the second diode D12 is electrically connected to the drive control unit 22, the cathode of the second diode D12 is also electrically connected to the control electrode of the second switch tube Q6 through the fourth resistor R94, the first end of the second switch tube Q6 is electrically connected to the second end of the first switch tube Q5, and the second end of the second switch tube Q6 is electrically connected to the ground end through the fifth resistor R112.

[0042] A first protection resistor R80 is further provided between the control electrode and the second end of the first switch tube Q5, and a second protection resistor R81 is further provided between the control electrode and the second end of the second switch tube Q6. A first filtering unit 11 is further provided between the control electrode and the second end of the first switch tube Q5 and between the control electrode and the second end of the second switch tube Q6, that is, a resistor R79 and a capacitor C22 are provided at both ends of the first protection resistor R80 and are connected in series with each other, and a similar filtering unit is also provided between the control electrode and the second end of the second switch tube Q6.

[0043] When the driving control unit 22 outputs a high level to the upper bridge arm 211 circuit of the W-phase winding, the current flows to the first switch tube Q5 through the second resistor R92 to turn it on; when the driving control unit 22 immediately outputs a low level to the upper bridge arm 211 circuit of the W-phase winding, the first switch tube Q5 is turned off, one current flows through the second resistor R92, and the other current flows out from the first resistor R91 through the first diode D11, thereby realizing the normal opening and accelerated shutdown of the switch tube.

[0044] By setting a protective resistor between the control electrode and the second end of the switch tube, the switch tube can be prevented from being accidentally turned on due to static electricity generated in the air when the switch tube is turned off, thereby ensuring that the switch tube is stably and reliably turned off, ensuring the control state of the switch tube, and at the same time, discharging energy through the protective resistor when the switch tube is turned off.

[0045] The phase current acquisition unit 3 is electrically connected to the second end of the second switch tube Q6 of each lower bridge arm circuit 212, and is used to collect the current phase current of the motor 4 and send it to the main control module 1, so as to judge the speed of the user's walking. The main control module 1 is used to compare the collected phase current of the motor 4 at the current moment with the preset current when the motor 4 is running, obtain the corresponding set duty cycle according to the comparison result, and send the set duty cycle to the drive control unit 22, and the drive control unit 22 controls the running state of the motor 4 according to the set duty cycle signal. Current sampling provides real-time motor 4 phase current information, which is used for feedback control, adjusting the running state of the motor 4, and ensuring that the motor 4 works according to the preset parameters.

[0046] When the user walks normally on the treadmill belt, the phase current generated will be less than the no-load current of the motor 4. To adapt to the user's running state, the duty cycle will be increased to increase the speed of the motor 4. At this time, the loaded current of the motor 4 will be greater than the no-load current. As the user's running speed increases further, the object of comparison should be adjusted to the loaded current, and the duty cycle needs to be further increased to increase the speed of the motor 4; if the user's running speed decreases, the duty cycle needs to be reduced to reduce the speed of the motor 4.

[0047] Therefore, in order to facilitate precise control of the rotation speed of motor 4 according to user needs, the duty cycle can be customized according to the size of the input voltage of motor 4, the usage status of the treadmill, and the user's running status and running habits. For example, when the collected phase current is less than 1A, the usage status of the treadmill is judged to be no-load state, and the corresponding duty cycle is set to 10%; when the collected phase current is greater than 1A and less than 1.5A, the user's running status is judged to be slow walking, and the corresponding duty cycle is set to 11%-20%; when the collected phase current is greater than 1.5A and less than 2.5A, the user's running status is judged to be jogging, and the corresponding duty cycle is set to 21%-35%; when the collected phase current is greater than 2.5A and less than 5A, the user's running status is judged to be sprinting, and the corresponding duty cycle is set to 36%-60%. The specific setting range of the preset current and the value of the duty cycle can be adjusted according to user needs. For example, when the input voltage of motor 4 (i.e., the first power supply end) is large, the duty cycle is set to increase; when the input voltage of motor 4 is small, the duty cycle is set to decrease; or if the user's running habit is jogging, the duty cycle should not be set too large; if the user's running habit is fast running, the duty cycle should not be set too small; the set current and the set duty cycle can also be further subdivided according to the user's needs.

[0048] When the motor 4 needs to perform a braking operation, the drive control unit 22 controls the first switch tube Q5 in each upper bridge arm circuit 211 to turn off, and the drive control unit 22 controls the second switch tube Q6 in each lower bridge arm circuit 212 to turn on, so that the three windings of the motor 4 (i.e., the W phase winding, the V phase winding, and the U phase winding) are short-circuited.

[0049] Since the second switch tubes Q6 of the three windings are all turned on and the resistance of the fifth resistor R112 is small, the corresponding windings of the motor 4 are connected to the ground terminal through the fifth resistor R112 (R113, R114), forming a short-circuit state. At this time, the rotation speed of the motor 4 slows down. When the short-circuit state to the ground is released, the rotation speed of the motor 4 is restored.

[0050] When encountering some abnormal situations (for example, the motor 4 rotates forward while the user is running but pushes backward), the rotor position changes abnormally, resulting in the current not passing through the winding and causing a sudden change in current. The phase current acquisition unit 3 collects the phase current of each phase respectively, and the main control module 1 obtains the total current based on the phase current of each phase. When it is detected that the total current exceeds the set current threshold, the main control module 1 controls to turn off the PWM output to avoid damaging the switch tube in the three-phase drive unit 21, thereby realizing software overcurrent protection.

[0051] When the user wants to stop running or runs slower and slower, the collected motor phase current decreases, and the speed of motor 4 drops to the minimum set speed by outputting the corresponding set duty cycle, that is, running at the set duty cycle in the no-load state.

[0052] like Figure 4 As shown, it also includes a total current acquisition unit 5 for collecting the three-phase total current; one end of the total current acquisition unit 5 is electrically connected to the drive control unit 22, and the other end of the total current acquisition unit 5 is electrically connected to the second end of each second switch tube (Q6, Q8, Q10) through a third diode (D1, D2, D3); the total current acquisition unit 5 also includes a second filtering unit, and the second filtering unit includes a resistor R20 and a capacitor C12.

[0053] The drive control unit 22 has hardware current protection inside. The total current collected by the total current acquisition unit 5 is compared with the set current threshold through the pin 9 port of the drive control unit 22. When the three-phase total current is detected to be overcurrent, the pin 8 port of the drive control unit 22 feeds back the overcurrent signal to the main control module 1, and sends a control signal to the motor 4 to stop it from rotating, thereby preventing the switch tube from burning out due to a sudden change in current, thereby improving the safety of use and the response speed.

[0054] The drive control unit 22 is used to compare the total current collected by the total current collection unit 5 with the reference voltage set by the drive control unit 22 when the motor 4 is running, and then determine whether the motor 4 is overcurrent. When it is determined that there is overcurrent, the drive control unit 22 feeds back the overcurrent information to the main control module 1 and controls the motor 4 to stop rotating. When the second switch tube in the lower bridge arm circuit 222 is turned on, the current generates a voltage drop at the second end of the second switch tube, flows through the third diode and the sampling resistor R15 to enter the drive control unit 22 to determine whether there is overcurrent.

[0055] like Figure 4 As shown, it also includes a bootstrap circuit unit 6, which includes a sixth resistor R103, a seventh resistor R104, a fourth diode (D25, D26, D27), a first capacitor (C4, C6, C8), and a second capacitor (C5, C7, C9), and each phase drive unit corresponds to a fourth diode, a first capacitor, and a second capacitor.

[0056] Taking one of the phase drive units as an example, the first capacitor C4 is connected in parallel to both ends of the drive control unit 22, the second capacitor C7 is connected in parallel to both ends of the first capacitor C4, the first end of the sixth resistor R103 and the first end of the seventh resistor R104 are electrically connected to the second power supply end (i.e., 15V) respectively, the second end of the sixth resistor R103 is electrically connected to the second end of the seventh resistor R104, the second end of the sixth resistor R103 is electrically connected to one end of the first capacitor C4 through the fourth diode D25, and the other end of the first capacitor C4 is electrically connected to the second end of the first switch tube Q5.

[0057] Taking the U-phase winding drive unit as an example, when the second switch tube Q10 is turned on, the interface A6 is equivalent to being grounded. At this time, one end of the first capacitor C8 and the second capacitor C9 are both grounded, and the other end thereof is electrically connected to the second power supply end (i.e., 15V) through the diode D27 and the resistor R103. Then, the second switch tube Q10 is turned off. At this time, the voltage difference between the control electrode of the first switch tube Q9 and its second end is sufficient to turn on the first switch tube Q9.

[0058] like Figure 4 As shown, it also includes a back-EMF collection unit 7 corresponding to each phase drive unit, and the back-EMF collection unit 7 includes a fifth diode D5, an eighth resistor R108, and a ninth resistor R107; the cathode of the fifth diode D5 is electrically connected to one end of the second capacitor C7, the anode of the fifth diode D5 is sequentially connected to the eighth resistor R108 and the ninth resistor R107, and then electrically connected to the corresponding winding of the motor 4, and the anode of the fifth diode D5 is respectively electrically connected to the second end of the first switch tube and the first end of the second switch tube of the same phase drive unit.

[0059] Since the first switch tube in the upper bridge arm 211 of the three-phase drive unit 21 adopts a suspended drive mode, the main control module 1 cannot directly control it. Therefore, when the motor 4 is started, the main control module 1 is powered by 3.3V and outputs PWM to the drive control unit 22. The drive control unit 22 is powered by 15V and sends the conduction control signal of the corresponding winding of the motor 4 to the three-phase drive unit 21, so that the corresponding winding is energized, and the rotor position is determined by the collected back electromotive force, thereby controlling the working state of the motor 4.

[0060] like Figure 3 As shown, the phase current acquisition unit 3 includes a reference voltage generating circuit 31 , a voltage follower circuit 32 , three current sampling resistors 33 , and three comparison circuits 34 .

[0061] The input end of each current sampling resistor 33 is electrically connected to the second end of the second switch tube of the corresponding lower bridge arm circuit 212, the output end of each current sampling resistor 33 is electrically connected to the first input end of the corresponding comparison circuit 34, the input end of the reference voltage generating circuit 31 is electrically connected to the third power supply end (i.e., VCC), the output end of the reference voltage generating circuit 31 is electrically connected to the first input end of the voltage following circuit 31, the output end and the second input end of the voltage following circuit 32 are electrically connected to the second input end of the corresponding comparison circuit 34, the output end of each comparison circuit 34 is electrically connected to the main control module 1, and the first power supply end of the comparison circuit 34 is electrically connected to the third power supply end (i.e., VCC). Wherein, the voltage following circuit 32 includes a voltage follower U5D.

[0062] The first switch in the upper bridge arm circuit 211 is turned on, and the current passes through the corresponding winding and enters the second switch in the lower bridge arm circuit 212 of the other winding, generating a voltage drop when it hits the ground, which is collected by the phase current collection unit 3. The voltage follower circuit 31 uses a resistor to divide the voltage to output 1.65V, and outputs a stable reference voltage to the current collection circuit 32 through an operational amplifier, and then the signal is amplified by the differential amplifier circuit 33 and transmitted to the main control module 1 for processing.

[0063] Resistors R47 and R49 divide the voltage of the third power supply terminal into a reference voltage, and improve the load capacity after passing through the voltage follower U5D. The reference voltage is compared with the voltage signal converted from the collected motor phase current, and the comparison circuit 34 outputs the comparison result to the main control module 1.

[0064] like Figure 2As shown, the power supply circuit 8 is also included. The power supply circuit 8 includes a first power supply terminal, a second power supply terminal and a third power supply terminal, that is, V+, 15V, and VCC. In this embodiment, V+ is 220V and VCC is 3V. The output voltage of the power supply circuit 8 can be adjusted according to the actual needs of the user. By setting a voltage regulator D19 in the power supply circuit 8, the voltage of VCCB is stabilized within a set range.

[0065] like Figure 5 As shown, a power-on buffer unit 10 is provided between the power supply circuit 8 and the AC input terminal 9, and the power-on buffer unit 10 is also connected to the main control module 1. Among them, the interface A1 is connected to the live wire of the AC input terminal 9, the interface A2 is connected to the neutral wire of the AC input terminal 9, and the interface A3 is grounded.

[0066] The power-on buffer unit 10 includes a relay K1, a tenth resistor R5, a third switch tube Q2, and a sixth diode D7. The movable contact of the relay K1 is electrically connected to the AC input terminal 9 through the thermistor RT1 and interfaces A1 and A2. The movable contact of the relay K1 is electrically connected to the power supply circuit 8. The first end of the power-on coil of the relay K1 is electrically connected to the second power supply terminal through the tenth resistor R5. The sixth diode D7 is connected in series between the first end and the second end of the power-on coil of the relay K1. The second end of the power-on coil of the relay K1 is electrically connected to the first end of the third switch tube Q2. The control electrode of the third switch tube Q2 is electrically connected to the main control module 1 through the eleventh resistor R21. The second end of the third switch tube Q2 is electrically connected to the ground terminal. Among them, the third switch tube Q2 is a field effect tube.

[0067] When the system is powered on, relay K1 is in the disconnected state, and current flows from interface A1 through thermistor RT1 into the power circuit 8; when the input voltage of the main control module 1 reaches the set value, the main control module 1 outputs a high level to the third switch tube Q2 to turn it on, and then relay K1 is energized to short-circuit the thermistor RT1.

[0068] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A treadmill motor control circuit system, characterized in that: The invention comprises a main control module (1), a motor drive module (2), a phase current acquisition unit (3) and a motor (4); the motor drive module (2) comprises a three-phase drive unit (21) and a drive control unit (22); the phase current acquisition unit (3) is electrically connected to the three-phase drive unit (21) and the main control module (1), respectively; the drive control unit (22) is electrically connected to the main control module (1) and the three-phase drive unit (21), respectively; and the three-phase drive unit (21) is electrically connected to the motor (4); Each phase drive unit of the three-phase drive unit (21) comprises an upper bridge arm circuit (211) and a lower bridge arm circuit (212), the upper bridge arm circuit (211) comprises a first resistor, a second resistor, a first diode, and a first switch tube, and the lower bridge arm circuit (212) comprises a third resistor, a fourth resistor, a fifth resistor, a second diode, and a second switch tube; The positive electrode of the first diode is electrically connected to the control electrode of the first switch tube through a first resistor, the negative electrode of the first diode is electrically connected to the drive control unit (22), the negative electrode of the first diode is also electrically connected to the control electrode of the first switch tube through a second resistor, the first end of the first switch tube is electrically connected to the positive electrode of the first power supply end, and the second end of the first switch tube is electrically connected to the corresponding winding of the motor (4); the positive electrode of the second diode is electrically connected to the control electrode of the second switch tube through a third resistor, the negative electrode of the second diode is electrically connected to the drive control unit (22), the negative electrode of the second diode is also electrically connected to the control electrode of the second switch tube through a fourth resistor, the first end of the second switch tube is electrically connected to the second end of the first switch tube, and the second end of the second switch tube is electrically connected to the ground end through a fifth resistor; The phase current acquisition unit (3) is electrically connected to the second end of the second switch tube of each lower bridge arm circuit (212), and is used to acquire the phase current of the motor (4) at the current moment and send it to the main control module (1); The main control module (1) is used to compare the collected phase current of the motor (4) at the current moment with the preset current when the motor (4) is running, obtain the corresponding set duty cycle according to the comparison result, and send the set duty cycle to the drive control unit (22), and the drive control unit (22) controls the running state of the motor (4) according to the set duty cycle signal.

2. The treadmill motor control circuit system according to claim 1, characterized in that: When the motor (4) needs to perform a braking operation, the drive control unit (22) controls the first switch tube in each upper bridge arm circuit (211) to be turned off, and the drive control unit (22) controls the second switch tube in each lower bridge arm circuit (212) to be turned on, so that the three windings of the motor (4) are short-circuited.

3. The treadmill motor control circuit system according to claim 1, characterized in that: It also includes a total current acquisition unit (5) for acquiring a three-phase total current; one end of the total current acquisition unit (5) is electrically connected to the drive control unit (22), and the other end of the total current acquisition unit (5) is electrically connected to the second end of each of the second switch tubes via a third diode; The drive control unit (22) is used to determine whether the motor (4) has an overcurrent according to the total current at the current moment collected by the total current collection unit (5) when the motor (4) is running; when it is determined that there is an overcurrent, the drive control unit (22) feeds back the overcurrent information to the main control module (1), and the main control module (1) stops outputting PWM.

4. The treadmill motor control circuit system according to claim 1, characterized in that: It also includes a bootstrap circuit unit (6), wherein the bootstrap circuit unit (6) includes a sixth resistor, a seventh resistor, a fourth diode, a first capacitor, and a second capacitor; The first capacitor is connected in parallel to both ends of the drive control unit (22), the second capacitor is connected in parallel to both ends of the first capacitor, the first end of the sixth resistor and the first end of the seventh resistor are respectively electrically connected to the second power supply end, the second end of the sixth resistor is electrically connected to the second end of the seventh resistor, the second end of the sixth resistor is respectively electrically connected to one end of the first capacitor through a fourth diode, the other end of the first capacitor is electrically connected to the second end of the first switch tube, and each phase drive unit corresponds to a fourth diode, a first capacitor, and a second capacitor.

5. The treadmill motor control circuit system according to claim 4, characterized in that: It also includes a back-electromotive force collection unit (7) corresponding to each phase drive unit, and the back-electromotive force collection unit (7) includes a fifth diode, an eighth resistor, and a ninth resistor; The cathode of the fifth diode is electrically connected to one end of the second capacitor, the anode of the fifth diode is connected in sequence to the eighth resistor and the ninth resistor and then electrically connected to the corresponding winding of the motor (4), and the anode of the fifth diode is electrically connected to the second end of the first switch tube and the first end of the second switch tube of the same phase drive unit respectively.

6. The treadmill motor control circuit system according to claim 1, characterized in that: The phase current acquisition unit (3) comprises a reference voltage generating circuit (31), a voltage follower circuit (32), three current sampling resistors (33), and three comparison circuits (34); The input end of each current sampling resistor (33) is electrically connected to the second end of the second switch tube of the corresponding lower bridge arm circuit (212); the output end of each current sampling resistor (33) is electrically connected to the first input end of the corresponding comparison circuit (34); the input end of the reference voltage generating circuit (31) is electrically connected to the third power supply end; the output end of the reference voltage generating circuit (31) is electrically connected to the first input end of the voltage follower circuit (32); the output end and the second input end of the voltage follower circuit (32) are respectively electrically connected to the second input end of the corresponding comparison circuit (34); the output end of each comparison circuit (34) is electrically connected to the main control module (1); and the first power supply end of the comparison circuit (34) is electrically connected to the third power supply end.

7. The treadmill motor control circuit system according to claim 1, characterized in that: It also includes a power supply circuit (8), the power supply circuit (8) including a first power supply end, a second power supply end and a third power supply end; a power-on buffer unit (10) is provided between the power supply circuit (8) and the AC input end (9), and the power-on buffer unit (10) is also connected to the main control module (1); The power-on buffer unit (10) comprises a relay, a tenth resistor, a third switch tube, and a sixth diode; the movable contact of the relay is electrically connected to the AC input terminal (9) through a thermistor; the movable contact of the relay is electrically connected to the power supply circuit (8); the first end of the relay power-on coil is electrically connected to the second power supply terminal through the tenth resistor; the sixth diode is connected in series between the first end and the second end of the relay power-on coil; the second end of the relay power-on coil is electrically connected to the first end of the third switch tube; the control electrode of the third switch tube is electrically connected to the main control module (1) through the eleventh resistor; and the second end of the third switch tube is electrically connected to the ground terminal.

8. The treadmill motor control circuit system according to any one of claims 1 to 7, characterized in that: A first protection resistor is provided between the control electrode of the first switch tube and the second end thereof, and a second protection resistor is provided between the control electrode of the second switch tube and the second end thereof.

9. The treadmill motor control circuit system according to claim 8, characterized in that: A first filtering unit (11) is provided between the control electrode of the first switch tube and its second end, and between the control electrode of the second switch tube and its second end.

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