Blade rotation control circuit, safety protection system, and lawn mowing robot

Abstract

This invention provides a blade disc operation control circuit, a safety protection system, and a lawnmower robot, relating to the field of power electronics technology. The circuit includes: a control module that acquires voltage signals from electronic devices and determines the current circuit state based on these signals; a drive module; a three-phase bridge module; and a brake protection module, including a first brake protection submodule or a second brake protection submodule. If the current circuit state is open-circuit, the control module outputs a brake signal to the drive module. Upon receiving the brake signal, the drive module drives the three-phase bridge module to send a first braking signal to the blade disc motor. If the current circuit state is short-circuit, the brake protection module sends a second braking signal to the blade disc motor. This invention can react quickly to open-circuit or short-circuit faults, causing the blade disc to stop rapidly, thus meeting the functional safety requirements of the lawnmower and reducing the risk of safety accidents.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more specifically, to a cutter head operation control circuit, a safety protection system, and a lawn mowing robot. Background Technology

[0002] The intelligent lawnmower can perform fully automatic mowing, with the blade motor operating at approximately 2500-4000 rpm / min. When the circuit system is working normally, if a rapid stop of the blade motor is required, the MCU can issue a blade brake command, and the blade will stop within 2-3 seconds. However, when the circuit system malfunctions, such as a sudden open circuit or short circuit to ground in the battery power supply, the blade motor will lose control of the MCU due to power loss. The blade will then continue to rotate for a long time before finally stopping, posing a safety risk when moving the lawnmower under these conditions. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a blade disc operation control circuit, a safety protection system, and a lawn mowing robot.

[0004] The embodiments of this application include the following:

[0005] In a first aspect, this application provides a tool turret rotation control circuit, applied to an electronic device, the circuit comprising:

[0006] The control module acquires the voltage signal of the electronic device and determines the current circuit state based on the voltage signal;

[0007] The drive module is communicatively connected to the control module;

[0008] The three-phase bridge module is electrically connected to the drive module and the cutter head motor.

[0009] The brake protection module is electrically connected to the three-phase bridge module and includes a first brake protection submodule or a second brake protection submodule.

[0010] If the current circuit state is open, the control module outputs a braking signal to the drive module; upon receiving the braking signal, the drive module drives the three-phase bridge module to send a first braking signal to the cutter head motor.

[0011] If the current circuit state is a short circuit, the brake protection module sends a second braking signal to the cutter head motor.

[0012] In one embodiment, the three-phase bridge module includes a first switching unit, a second switching unit, and a third switching unit;

[0013] The first control terminal of the three-phase bridge module includes the first control terminal of the first switch unit, the first control terminal of the second switch unit, and the first control terminal of the third switch unit; the second control terminal of the three-phase bridge module includes the second control terminal of the first switch unit, the second control terminal of the second switch unit, and the second control terminal of the third switch unit.

[0014] The first output terminal of the first switching unit is electrically connected to the first output terminal of the second switching unit, the first output terminal of the second switching unit is electrically connected to the first output terminal of the third switching unit, the second input terminal of the first switching unit is electrically connected to the second input terminal of the second switching unit, and the second input terminal of the second switching unit is electrically connected to the second input terminal of the third switching unit.

[0015] The first input terminal of the first switch unit is electrically connected to the second output terminal of the first switch unit, the first input terminal of the second switch unit is electrically connected to the second output terminal of the second switch unit, and the first input terminal of the third switch unit is electrically connected to the second output terminal of the third switch unit.

[0016] In one embodiment, when the drive module receives the braking signal, the drive module outputs a first switching signal to the first control terminal of the three-phase bridge module and a second switching signal to the second control terminal of the three-phase bridge module; the first switching signal is at a low level and the second switching signal is at a high level.

[0017] In one embodiment, the first switching unit includes a first MOSFET and a second MOSFET, the second switching unit includes a third MOSFET and a fourth MOSFET, and the third switching unit includes a fifth MOSFET and a sixth MOSFET.

[0018] The gate of the first MOSFET serves as the first control terminal of the first switching unit, the gate of the second MOSFET serves as the second control terminal of the first switching unit, the source of the first MOSFET serves as the first input terminal of the first switching unit, the drain of the first MOSFET serves as the first output terminal of the first switching unit, the source of the second MOSFET serves as the second input terminal of the first switching unit, and the drain of the second MOSFET serves as the second output terminal of the first switching unit.

[0019] The gate of the third MOS transistor serves as the first control terminal of the second switching unit, the gate of the fourth MOS transistor serves as the second control terminal of the second switching unit, the source of the third MOS transistor serves as the first input terminal of the second switching unit, the drain of the third MOS transistor serves as the first output terminal of the second switching unit, the source of the fourth MOS transistor serves as the second input terminal of the second switching unit, and the drain of the fourth MOS transistor serves as the second output terminal of the second switching unit.

[0020] The gate of the fifth MOS transistor serves as the first control terminal of the third switching unit, the gate of the sixth MOS transistor serves as the second control terminal of the third switching unit, the source of the fifth MOS transistor serves as the first input terminal of the third switching unit, the drain of the fifth MOS transistor serves as the first output terminal of the third switching unit, the source of the sixth MOS transistor serves as the second input terminal of the third switching unit, and the drain of the sixth MOS transistor serves as the second output terminal of the third switching unit.

[0021] In one embodiment, the first brake protection submodule includes a first transistor, a second transistor, and a third transistor;

[0022] The base of the first transistor is electrically connected to the battery, the base of the first transistor is also electrically connected to the base of the second transistor, and the base of the second transistor is also electrically connected to the base of the third transistor.

[0023] The emitter of the first transistor is electrically connected to the emitter of the second transistor, and the emitter of the second transistor is also electrically connected to the emitter of the third transistor.

[0024] The collector of the first transistor is electrically connected to the second input terminal of the first switching unit, the collector of the second transistor is electrically connected to the second input terminal of the second switching unit, and the collector of the third transistor is electrically connected to the second input terminal of the third switching unit.

[0025] In one embodiment, the first brake protection submodule further includes an energy storage unit, the first end of which is electrically connected to the emitter of the first transistor, and the second end of which is grounded.

[0026] In one embodiment, the second brake protection submodule includes a first relay and a second relay. The second pin of the first relay is electrically connected to the first input terminal of the first switching unit, the seventh pin of the first relay is electrically connected to the first input terminal of the second switching unit, and the second pin of the second relay is electrically connected to the first input terminal of the third switching unit.

[0027] In one embodiment, the circuit further includes a connection terminal, wherein a first pin of the connection terminal is electrically connected to a first input terminal of the first switching unit, a second pin of the connection terminal is electrically connected to a first input terminal of the second switching unit, and a third pin of the connection terminal is electrically connected to a first input terminal of the third switching unit;

[0028] The first pin of the connection terminal is electrically connected to the U phase of the cutter head motor, the second pin of the connection terminal is electrically connected to the V phase of the cutter head motor, and the third pin of the connection terminal is electrically connected to the W phase of the cutter head motor.

[0029] In one embodiment, the fourth pin of the connection terminal is electrically connected to the W phase of the cutter head motor, the fifth pin of the connection terminal is electrically connected to the V phase of the cutter head motor, and the sixth pin of the connection terminal is electrically connected to the U phase of the cutter head motor.

[0030] Secondly, this application provides a safety protection system, which includes the cutter head operation control circuit as described in the first aspect.

[0031] Thirdly, this application provides a lawnmower robot, which includes the safety protection system described in the first aspect.

[0032] The blade disc operation control circuit proposed in this application can react quickly when an open circuit or short circuit fault occurs in the circuit, so as to stop the blade disc quickly, thereby meeting the functional safety requirements of the lawnmower and reducing the risk of safety accidents. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of one module of the cutter head rotation control circuit provided in this application;

[0035] Figure 2 A circuit diagram of the driving module provided in this application;

[0036] Figure 3 A circuit diagram of the three-phase bridge module provided in this application;

[0037] Figure 4 A circuit diagram of the first brake protection submodule provided in this application;

[0038] Figure 5 One of the circuit diagrams of the second brake protection submodule provided in this application;

[0039] Figure 6 A second circuit diagram of the second brake protection submodule provided in this application;

[0040] Figure 7 A partial circuit diagram of the cutter head rotation control circuit provided in this application;

[0041] Figure 8 A circuit diagram of the connection terminals provided in this application.

[0042] Icons: 110 - Control module; 120 - Drive module; 130 - Three-phase bridge module; 140 - Brake protection module; 200 - Battery; 300 - Cutter head motor; U2 - First switching unit; U3 - Second switching unit; U4 - Third switching unit; Q1 - First MOSFET; Q2 - Second MOSFET; Q3 - Third MOSFET; Q4 - Fourth MOSFET; Q5 - Fifth MOSFET; Q6 - Sixth MOSFET; Q7 - First transistor; Q8 - Second transistor; Q9 - Third transistor; J1 - Connection terminal; J2 - First relay; J3 - Second relay. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0046] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0047] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0048] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0049] Example 1

[0050] The intelligent lawnmower can perform fully automatic mowing, with the blade motor 300 operating at approximately 2500-4000 rpm / min. When the circuit system is working normally, if a rapid stop of the blade motor 300 is required, the MCU can issue a blade brake command, and the blade will stop within 2-3 seconds. However, if the circuit system malfunctions, such as a sudden open circuit or short circuit to ground in the battery 200, the MCU will lose power, and the blade motor 300 will lose the MCU's control command. The blade will then continue to rotate for a considerable time before finally stopping. During this time, the MCU loses its safety monitoring, posing a risk of accidents when moving the lawnmower.

[0051] Based on this, this embodiment provides a cutter head operation control circuit, which can brake the cutter head motor 300 in a timely manner in the event of a sudden open circuit or short circuit to ground in the power supply of the battery 200, so as to stop the cutter head quickly.

[0052] For details, please refer to Figure 1 , Figure 1 A system block diagram of a cutter head rotation control circuit provided in an embodiment of this application, the circuit comprising:

[0053] The control module 110 acquires the voltage signal of the electronic device and determines the current circuit state based on the voltage signal;

[0054] The drive module 120 is communicatively connected to the control module 110;

[0055] The three-phase bridge module 130 is electrically connected to the drive module 120 and the cutter head motor 300;

[0056] Brake protection module 140 is electrically connected to the three-phase bridge module 130 and includes a first brake protection submodule or a second brake protection submodule.

[0057] If the current circuit state is open, the control module 110 outputs a braking signal to the drive module 120; upon receiving the braking signal, the drive module 120 drives the three-phase bridge module 130 to send a first braking signal to the cutter head motor 300.

[0058] If the current circuit state is a short circuit, the brake protection module 140 sends a second braking signal to the cutter head motor 300.

[0059] When the electronic device's circuitry is operating normally, battery 200 supplies power to control module 110 via DC-DC converter through battery voltage signal VBAT. Control module 110 outputs a speed control PWM signal to drive module 120. Simultaneously, drive module 120, based on the detected three-phase Hall effect signals from the motor, outputs corresponding motor control signals to drive three-phase bridge module 130, ensuring normal motor operation. Control module 110 also detects the motor speed feedback signal FG and adjusts the duty cycle of the PWM signal to achieve closed-loop speed control.

[0060] When braking is required, the control module 110 sends a braking signal BRAKE to the drive module 120. The drive module 120 controls its output to turn off the upper transistors and turn on the lower transistors of each switching unit in the three-phase bridge module 130, causing a short circuit in the three-phase UVW of the cutter head motor 300. The motor generates a reverse braking torque, thereby achieving the function of quickly stopping the cutter head. Figure 1 In this context, BLADE_FG represents the feedback signal, BLADE_PWM represents the PWM signal, BLADE_BRAKEZ represents the brake signal, and BLADE_DIR represents the motor direction signal, which is responsible for controlling the forward and reverse rotation of the motor.

[0061] For example, the control module 110 can be a microcontroller such as an MCU, the cutter head motor 300 can be a brushless DC motor (BLDC), and the core component of the drive module 120 is the drive IC, U1. For example, the model of U1 is a brushless DC motor driver MS4931 with built-in stall protection and self-starting low power mode.

[0062] When VBAT is open in the circuit, and the cutter head is running, the control module 110 will monitor the VBAT voltage in real time. When the VBAT voltage suddenly drops by 5V, it is considered that VBAT is open. At this time, the principle of generating the first braking signal is similar to controlling the brake of the cutter head motor during normal circuit operation: the control module 110 controls the brake signal BRAKE to a low level, and the drive module 120 controls its output to turn off the upper transistors and turn on the lower transistors of each switching unit in the three-phase bridge module 130, sending the first braking signal to the cutter head motor, causing the three-phase UVW of the cutter head motor 300 to be short-circuited. For example, the MCU's operating voltage is 3.3V, the driver IC's operating voltage is 8-35V, and the VBAT voltage is set to 18-25V, so that even when the VBAT voltage suddenly drops by 5V, the MCU and driver IC can still work normally.

[0063] When VBAT is short-circuited in the circuit, the power supply to the control module 110 and drive module 120 will drop rapidly and cease normal operation, and the GATE drive stage of the switching unit in the three-phase bridge module 130 will become high-impedance. At this time, the brake protection module 140 intervenes and sends a second braking signal to the cutter head motor. The first and second brake protection submodules operate on different principles, but their ultimate goal is to short-circuit the three phases of the cutter head motor 300 to generate braking torque, thereby stopping its operation. The specific principle of rapidly stopping the cutter head will be explained in detail later in conjunction with the specific circuit structures of the three-phase bridge module 130 and the brake protection module 140.

[0064] Please see Figure 2 and Figure 3 , Figure 2 This is a circuit diagram of the driving module 120 provided in an embodiment of this application. Figure 2 The winning bid identified several different signals sent by the driver module 120; Figure 3 A circuit diagram of a three-phase bridge module 130 provided in an embodiment of this application; in one embodiment, the three-phase bridge module 130 includes a first switching unit U2, a second switching unit U3, and a third switching unit U4;

[0065] In one embodiment, the drive module 120 is configured to output a first switch signal to the first control terminal of the three-phase bridge module 130 when the drive module 120 receives the brake signal, and the drive module 120 is also configured to output a second switch signal to the second control terminal of the three-phase bridge module 130, wherein the first switch signal is at a low level and the second switch signal is at a high level.

[0066] The first control terminal of the three-phase bridge module 130 includes the first control terminal of the first switch unit U2, the first control terminal of the second switch unit U3, and the first control terminal of the third switch unit U4; the second control terminal of the three-phase bridge module 130 includes the second control terminal of the first switch unit U2, the second control terminal of the second switch unit U3, and the second control terminal of the third switch unit U4.

[0067] The first output terminal of the first switch unit U2 is electrically connected to the first output terminal of the second switch unit U3, the first output terminal of the second switch unit U3 is electrically connected to the first output terminal of the third switch unit U4, the second input terminal of the first switch unit U2 is electrically connected to the second input terminal of the second switch unit U3, and the second input terminal of the second switch unit U3 is electrically connected to the second input terminal of the third switch unit U4.

[0068] The first input terminal of the first switch unit U2 is electrically connected to the second output terminal of the first switch unit U2, the first input terminal of the second switch unit U3 is electrically connected to the second output terminal of the second switch unit U3, and the first input terminal of the third switch unit U4 is electrically connected to the second output terminal of the third switch unit U4.

[0069] The first switching unit U2 includes a first MOSFET Q1 and a second MOSFET Q2; the second switching unit U3 includes a third MOSFET Q3 and a fourth MOSFET Q4; and the third switching unit U4 includes a fifth MOSFET Q5 and a sixth MOSFET Q6.

[0070] The gate of the first MOSFET Q1 serves as the first control terminal of the first switching unit U2, the gate of the second MOSFET Q2 serves as the second control terminal of the first switching unit U2, the source of the first MOSFET Q1 serves as the first input terminal of the first switching unit U2, the drain of the first MOSFET Q1 serves as the first output terminal of the first switching unit U2, the source of the second MOSFET Q2 serves as the second input terminal of the first switching unit U2, and the drain of the second MOSFET Q2 serves as the second output terminal of the first switching unit U2.

[0071] The gate of the third MOSFET Q3 serves as the first control terminal of the second switching unit U3, the gate of the fourth MOSFET Q4 serves as the second control terminal of the second switching unit U3, the source of the third MOSFET Q3 serves as the first input terminal of the second switching unit U3, the drain of the third MOSFET Q3 serves as the first output terminal of the second switching unit U3, the source of the fourth MOSFET Q4 serves as the second input terminal of the second switching unit U3, and the drain of the fourth MOSFET Q4 serves as the second output terminal of the second switching unit U3.

[0072] The gate of the fifth MOSFET Q5 serves as the first control terminal of the third switching unit U4, the gate of the sixth MOSFET Q6 serves as the second control terminal of the third switching unit U4, the source of the fifth MOSFET Q5 serves as the first input terminal of the third switching unit U4, the drain of the fifth MOSFET Q5 serves as the first output terminal of the third switching unit U4, the source of the sixth MOSFET Q6 serves as the second input terminal of the third switching unit U4, and the drain of the sixth MOSFET Q6 serves as the second output terminal of the third switching unit U4.

[0073] When the first control terminal of the three-phase bridge module 130 receives a low level and the second control terminal of the three-phase bridge module 130 receives a high level, the first MOSFET Q1, the third MOSFET Q3 and the fifth MOSFET Q5 are turned off, and the second MOSFET Q2, the fourth MOSFET Q4 and the sixth MOSFET Q6 are turned on.

[0074] Please see Figure 2 and Figure 3 GHA2, GHB2, and GHC2 represent the first switching signals, GLA2, GLB2, and GLC2 represent the second switching signals, and SHA2, SHB2, and SHC2 are connected to the U, V, and W phases of the cutter head motor, respectively. When the cutter head motor is operating normally, one of GHA2, GHB2, and GHC2 is at a high level, and one of GLA2, GLB2, and GLC2 is at a high level, but GHA and GLA cannot be high simultaneously; the same applies to groups B and C. The upper transistors (including the first MOSFET Q1, the third MOSFET Q3, and the fifth MOSFET Q5) and the lower transistors (the second MOSFET Q2, the fourth MOSFET Q4, and the sixth MOSFET Q6) periodically alternately conduct, allowing current to flow in different directions through the three phases (UVW) of the motor, thus enabling normal motor operation. When the drive module 120 receives the braking signal, GHA2, GHB2, and GHC2 go low, while GLA2, GLB2, and GLC2 go high. At this time, the first MOSFET Q1, the third MOSFET Q3, and the fifth MOSFET Q5 are turned off, while the second MOSFET Q2, the fourth MOSFET Q4, and the sixth MOSFET Q6 are turned on. SHA2, SHB2, and SHC2 have the same potential, therefore the U, V, and W phase potentials of the cutter head motor connected to SHA2, SHB2, and SHC2 are also the same, generating the first braking signal. This causes a three-phase short circuit in the cutter head motor, thus generating braking torque. Furthermore, in Figures 2-7 In this context, all signals with the same label indicate that their locations are actually connected, which will not be elaborated further below.

[0075] Figure 2Resistors R9, R10, R11, R12, R13, R15, R17, R21, R25, R16, R17, R18, R19, R20, R21, R22, R23, R26, R27, and R29 are current-limiting protection resistors for the driver IC. The RC filter network composed of capacitors C12, C13, C14, C15, and C22, as well as capacitor C21 and resistors R30 and R31, and the filter network composed of capacitors C18, C19, C20, resistor R14, and transient suppression diode D4, all serve to filter and prevent transient high voltages from damaging the circuit and critical components such as the driver IC.

[0076] Figure 3 In the first switching unit U2, pin 2 represents the first control terminal, pin 4 represents the second control terminal, pins 7 and 8 (connected in parallel) represent the first output terminal, pin 1 represents the first input terminal, pins 5 and 6 (connected in parallel) represent the second output terminal, and pin 3 represents the second input terminal. The second switching unit U3 and the third switching unit U4 are similar and will not be described in detail here. Figure 3 C1 is a decoupling capacitor, C2 is a coupling capacitor, and C1, C2, and R1 together form a filter and electromagnetic isolation for the reference ground PGND. C5, C6, C7, R8, and C11 have similar functions.

[0077] Please see Figure 4 In one embodiment, the first brake protection submodule includes a first transistor Q7, a second transistor Q8, and a third transistor Q9;

[0078] The base of the first transistor Q7 is electrically connected to the battery 200, the base of the first transistor Q7 is also electrically connected to the base of the second transistor Q8, and the base of the second transistor Q8 is also electrically connected to the base of the third transistor Q9.

[0079] The emitter of the first transistor Q7 is electrically connected to the emitter of the second transistor Q8, and the emitter of the second transistor Q8 is also electrically connected to the emitter of the third transistor Q9.

[0080] The collector of the first transistor Q7 is electrically connected to the second input terminal of the first switching unit U2, the collector of the second transistor Q8 is electrically connected to the second input terminal of the second switching unit U3, and the collector of the third transistor Q9 is electrically connected to the second input terminal of the third switching unit U4.

[0081] When the first transistor Q7, the second transistor Q8, and the third transistor Q9 are turned on, the first brake protection submodule outputs a high level to the second control terminal of the three-phase bridge module 130.

[0082] Figure 4 VB_COM represents the base voltage of the transistor. It should be noted that although GLA2, GLB2, and GLC2 are connected to the driver IC at this time, the driver IC is actually powered off. Therefore, the signals of GLA2, GLB2, and GLC2 are provided by the brake protection module.

[0083] In one embodiment, the first brake protection submodule further includes an energy storage unit. The first end of the energy storage unit is electrically connected to the emitter of the first transistor Q7, and the second end of the energy storage unit is grounded. The energy storage unit is used to supply power to the first transistor Q7, the second transistor Q8, and the third transistor Q9 when the first transistor Q7, the second transistor Q8, and the third transistor Q9 are turned on.

[0084] In this embodiment, the energy storage unit includes a second energy storage capacitor C24 and a third energy storage capacitor C25. These are electrolytic capacitors, whose main function is to store electrical energy to drive the lower transistors of the three-phase bridge, namely Q2, Q4, and Q6, to conduct. In actual use, only one of them can be used, with the other as a backup.

[0085] When VBAT is short-circuited in the circuit system, the power supply to the MCU and driver IC will drop rapidly and cease normal operation, and the gate drive stage of the upper and lower transistors of the three-phase bridge will become high-impedance. At this time, either the first braking protection submodule or the second braking protection submodule can be used.

[0086] When the first brake protection submodule is used, the lower transistor of the three-phase bridge is turned on, thereby achieving the function of rapid stop of the cutter head. This scheme uses transistors and energy storage capacitors, which has the characteristics of low cost. The circuit operation process is as follows:

[0087] When VBAT is normal, transistors Q7, Q8, and Q9 are all off, and the GLA2 / GLB2 / GLC2 signals are normally controlled by the driver IC.

[0088] When VBAT is short-circuited, transistors Q7, Q8, and Q9 are turned on, and the GLA2 / GLB2 / GLC2 signals all output high voltages stored in the energy storage unit. The lower transistors of the three-phase bridge (second MOSFET Q2, fourth MOSFET Q4, and sixth MOSFET Q6) are turned on, and SHA2, SHB2, and SHC2 have the same potential. Therefore, the U, V, and W phase potentials of the cutter head motor connected to SHA2, SHB2, and SHC2 are also the same, generating a second braking signal to achieve three-phase short-circuit braking of the motor.

[0089] Please see Figure 5 and Figure 6In one embodiment, the second brake protection submodule includes a first relay J2 and a second relay J3. The second pin of the first relay J2 is electrically connected to the first input terminal of the first switching unit U2, the seventh pin of the first relay J2 is electrically connected to the first input terminal of the second switching unit U3, and the second pin of the second relay J3 is electrically connected to the first input terminal of the third switching unit U4.

[0090] The second brake protection submodule directly sends a second braking signal to the cutter head motor via a relay, causing a three-phase short circuit in the UVW phases of the cutter head motor, thus achieving rapid braking. The circuit operation process is as follows:

[0091] When VBAT is normal, the coils of the first relay J2 and the second relay J3 are energized and engaged. The SHA2 / SHB2 / SHC2 signals are connected to the NO pin of the relay and are in a floating state. The driver IC normally controls the three-phase bridge circuit to drive the motor.

[0092] When VBAT is short-circuited, the coils of the first relay J2 and the second relay J3 are de-energized, and the SHA2 / SHB2 / SHC2 signals are instantly switched to the NC pin of the relays. At this time, the SHA2 / SHB2 / SHC2 signal points are the same, and the U, V, and W phase potentials of the cutter head motor connected to SHA2, SHB2, and SHC2 are also the same, thus achieving braking.

[0093] In addition, the second brake protection submodule also includes a Schottky diode D5, a transistor Q4, capacitors C16 and C17, a ferrite bead FB, resistors R24 and R28, and a Schottky diode D6 connected to the first relay J2. It also includes a Schottky diode D8, a transistor Q8, a capacitor C23, resistors R34 and R37, and a Schottky diode D10 connected to the second relay J3.

[0094] Schottky diodes D5 and D8 protect the relay from damage caused by reverse voltage pulses resulting from a sudden interruption of current in the relay. Transistors Q4 and Q8 conduct when VBAT is short-circuited in the circuit system, enabling the second brake protection submodule to operate. Resistors, capacitors, ferrite beads, and diodes in the circuit perform current limiting, filtering, and circuit stabilization functions for the second brake protection submodule.

[0095] Please see Figure 8 In one embodiment, the circuit further includes a connection terminal J1, the first pin of which is electrically connected to the first input terminal of the first switching unit U2, the second pin of which is electrically connected to the first input terminal of the second switching unit U3, and the third pin of which is electrically connected to the first input terminal of the third switching unit U4.

[0096] The first pin of the connection terminal J1 is also electrically connected to the U phase of the cutter head motor 300, the second pin of the connection terminal J1 is also electrically connected to the V phase of the cutter head motor 300, and the third pin of the connection terminal J1 is also electrically connected to the W phase of the cutter head motor 300.

[0097] In one embodiment, the fourth pin of the connection terminal J1 is also electrically connected to the W phase of the cutter head motor 300, and the fourth pin of the connection terminal J1 is used to receive the first Hall feedback signal HALL2_HC of the cutter head motor 300 phase. The fifth pin of the connection terminal J1 is also electrically connected to the V phase of the cutter head motor 300, and the fifth pin of the connection terminal J1 is used to receive the second Hall feedback signal HALL2_HB of the cutter head motor 300 phase. The sixth pin of the connection terminal J1 is also electrically connected to the U phase of the cutter head motor 300, and the sixth pin of the connection terminal J1 is used to receive the third Hall feedback signal HALL2_HA of the cutter head motor 300 phase.

[0098] Pins 1, 2, and 3 of the connection terminal are used to transmit SHA1, SHB1, and SHC1 signals; these directly control the U, V, and W phases of the cutter head motor. When the cutter head motor is operating normally, the driver IC sends a PWM signal to it. Pins 4, 5, and 6 of the connection terminal are used to receive Hall feedback signals from the W, V, and U phases of the cutter head motor. The driver IC combines the Hall feedback signals and the PWM signal to drive the three-phase bridge module, allowing the cutter head motor to operate normally. Simultaneously, the MCU detects the motor speed's FG signal and adjusts the duty cycle of the PWM signal to achieve closed-loop speed control.

[0099] Figure 7 The filter and electrostatic discharge (ESD) suppression components between the cutter head motor and other modules include an RC filter network consisting of resistors R5, R6, R7, R2, R3, R4, C3, C4, C8, C9, and C10, as well as ferrite beads (FB) and ESD protection diodes (D1, D2, and D3). This effectively prevents interference between other modules and between ground and electrodes. For example, the resistor in this application is a 0603 packaged resistor.

[0100] Tests have shown that the blade disc operation control circuit proposed in this application can quickly stop the blade disc within 4 seconds in the event of a sudden open circuit or short circuit to ground during the operation of the intelligent lawnmower blade disc.

[0101] The blade disc operation control circuit proposed in this application can react quickly when an open circuit or short circuit fault occurs in the circuit, so as to stop the blade disc quickly, thereby meeting the functional safety requirements of the lawnmower and reducing the risk of safety accidents.

[0102] Example 2

[0103] This embodiment also provides a safety protection system, which includes the cutter head rotation control circuit as described in any of the above embodiments.

[0104] Example 3

[0105] This embodiment also provides a lawnmower robot, which includes a safety protection system as described in any of the above embodiments.

[0106] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cutter head rotation control circuit, applied in electronic equipment, characterized in that, The circuit includes: The control module acquires the voltage signal of the electronic device and determines the current circuit state based on the voltage signal; The drive module is communicatively connected to the control module; The three-phase bridge module is electrically connected to the drive module and the cutter head motor. The three-phase bridge module includes a first switching unit, a second switching unit and a third switching unit. The first control terminal of the three-phase bridge module includes the first control terminal of the first switch unit, the first control terminal of the second switch unit, and the first control terminal of the third switch unit; the second control terminal of the three-phase bridge module includes the second control terminal of the first switch unit, the second control terminal of the second switch unit, and the second control terminal of the third switch unit. The first output terminal of the first switching unit is electrically connected to the first output terminal of the second switching unit, the first output terminal of the second switching unit is electrically connected to the first output terminal of the third switching unit, the second input terminal of the first switching unit is electrically connected to the second input terminal of the second switching unit, and the second input terminal of the second switching unit is electrically connected to the second input terminal of the third switching unit. The first input terminal of the first switch unit is electrically connected to the second output terminal of the first switch unit, the first input terminal of the second switch unit is electrically connected to the second output terminal of the second switch unit, and the first input terminal of the third switch unit is electrically connected to the second output terminal of the third switch unit. The brake protection module is electrically connected to the three-phase bridge module and includes a first brake protection submodule or a second brake protection submodule. If the current circuit state is open, the control module outputs a braking signal to the drive module; upon receiving the braking signal, the drive module drives the three-phase bridge module to send a first braking signal to the cutter head motor, including: when the drive module receives the braking signal, the drive module outputs a first switching signal to the first control terminal of the three-phase bridge module and a second switching signal to the second control terminal of the three-phase bridge module; the first switching signal is low level and the second switching signal is high level; If the current circuit state is a short circuit, the brake protection module sends a second braking signal to the cutter head motor; The connection terminal has a first pin electrically connected to the first input terminal of the first switching unit, a second pin electrically connected to the first input terminal of the second switching unit, and a third pin electrically connected to the first input terminal of the third switching unit. The first pin of the connection terminal is electrically connected to the U phase of the cutter head motor, the second pin of the connection terminal is electrically connected to the V phase of the cutter head motor, and the third pin of the connection terminal is electrically connected to the W phase of the cutter head motor.

2. The cutter head rotation control circuit according to claim 1, characterized in that, The first switching unit includes a first MOSFET and a second MOSFET, the second switching unit includes a third MOSFET and a fourth MOSFET, and the third switching unit includes a fifth MOSFET and a sixth MOSFET; The gate of the first MOSFET serves as the first control terminal of the first switching unit, the gate of the second MOSFET serves as the second control terminal of the first switching unit, the source of the first MOSFET serves as the first input terminal of the first switching unit, the drain of the first MOSFET serves as the first output terminal of the first switching unit, the source of the second MOSFET serves as the second input terminal of the first switching unit, and the drain of the second MOSFET serves as the second output terminal of the first switching unit. The gate of the third MOS transistor serves as the first control terminal of the second switching unit, the gate of the fourth MOS transistor serves as the second control terminal of the second switching unit, the source of the third MOS transistor serves as the first input terminal of the second switching unit, the drain of the third MOS transistor serves as the first output terminal of the second switching unit, the source of the fourth MOS transistor serves as the second input terminal of the second switching unit, and the drain of the fourth MOS transistor serves as the second output terminal of the second switching unit. The gate of the fifth MOS transistor serves as the first control terminal of the third switching unit, the gate of the sixth MOS transistor serves as the second control terminal of the third switching unit, the source of the fifth MOS transistor serves as the first input terminal of the third switching unit, the drain of the fifth MOS transistor serves as the first output terminal of the third switching unit, the source of the sixth MOS transistor serves as the second input terminal of the third switching unit, and the drain of the sixth MOS transistor serves as the second output terminal of the third switching unit.

3. The cutter head rotation control circuit according to claim 1, characterized in that, The first brake protection submodule includes a first transistor, a second transistor, and a third transistor; The base of the first transistor is electrically connected to the battery, the base of the first transistor is also electrically connected to the base of the second transistor, and the base of the second transistor is also electrically connected to the base of the third transistor. The emitter of the first transistor is electrically connected to the emitter of the second transistor, and the emitter of the second transistor is also electrically connected to the emitter of the third transistor. The collector of the first transistor is electrically connected to the second input terminal of the first switching unit, the collector of the second transistor is electrically connected to the second input terminal of the second switching unit, and the collector of the third transistor is electrically connected to the second input terminal of the third switching unit.

4. The cutter head rotation control circuit according to claim 3, characterized in that, The first brake protection submodule also includes an energy storage unit. The first end of the energy storage unit is electrically connected to the emitter of the first transistor, and the second end of the energy storage unit is grounded.

5. The cutter head rotation control circuit according to claim 1, characterized in that, The second brake protection submodule includes a first relay and a second relay. The second pin of the first relay is electrically connected to the first input terminal of the first switching unit, the seventh pin of the first relay is electrically connected to the first input terminal of the second switching unit, and the second pin of the second relay is electrically connected to the first input terminal of the third switching unit.

6. The cutter head rotation control circuit according to claim 1, characterized in that, The fourth pin of the connection terminal is electrically connected to the W phase of the cutter head motor, the fifth pin of the connection terminal is electrically connected to the V phase of the cutter head motor, and the sixth pin of the connection terminal is electrically connected to the U phase of the cutter head motor.

7. A safety protection system, characterized in that, The system includes the cutter head rotation control circuit as described in any one of claims 1-6.

8. A lawnmower robot, characterized in that, The robot includes the safety protection system as described in claim 7.

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