A loss of power active safety control system

Abstract

The application discloses a kind of power-off active safety control systems, including battery pack, battery pack is connected with first resistance, first resistance is connected with the collector of first tetrode, the base of first tetrode is connected with in-vehicle software.The power-off active safety control system is closed by key ignition switch, monitors key ignition switch voltage, and the software "power-off maintenance enable" signal is pulled high by in-vehicle software, and first tetrode is opened, after power-on is completed, the voltage of second tetrode is opened by the voltage division effect of second resistance and third resistance, so that NMOS transistor is in closed state, at this time, it is in normal working condition, after key ignition switch line is unexpectedly powered off, second tetrode is in closed state, battery pack voltage flows through first resistance and opens NMOS transistor, so that battery pack voltage flows through inductance L after filtering, through NMOS transistor again through NTC resistance, continuously power supply module is powered, and it can prevent vehicle out of control due to key ignition switch line disconnection.

Description

Technical Field

[0001] This invention relates to the field of electric forklift technology, and in particular to an active safety control system for power failure. Background Technology

[0002] Electric forklifts use batteries as a power source and convert electrical energy into mechanical energy through a motor to drive the forklift to move and convert electrical energy into hydraulic energy to drive the working device. Electric forklifts are characterized by small power unit size, simple and flexible operation, low noise, and no exhaust emissions.

[0003] CN109019443A discloses a forklift control system, including a brake-steering assist component and a main functional component. It also includes an auxiliary drive control unit connected to the brake-steering assist component to enable braking and steering functions, and a main functional drive control unit connected to the main functional component to enable lifting, tilting, and lateral movement functions. The brake-steering assist component and the main functional component are driven independently by the auxiliary drive control unit and the main functional drive control unit, respectively. This satisfies the low energy requirements of the auxiliary drive control unit while simultaneously meeting the high energy requirements of the main functional component. This allows for the use of a large and a small motor configuration, ensuring full utilization of the motor's output energy and avoiding energy waste caused by using the same motor for both the brake-steering assist component and the main functional component, thus contributing to energy conservation. The invention also provides a forklift with a low-cost forklift control system.

[0004] The auxiliary power supply of the motor controller in the aforementioned conventional low-voltage system vehicle is drawn from the power battery and forms a power supply circuit through the key ignition switch. During vehicle operation, especially when driving downhill, if the key ignition switch circuit is broken or the key ignition switch signal is accidentally disconnected by the user, the auxiliary power supply of the controller will be lost, the controller will stop working, and the vehicle will be out of control, posing a significant safety hazard. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an active safety control system for power failure, comprising a battery pack, wherein the battery pack is connected to a first resistor, the first resistor is connected to the collector of a first transistor, the base of the first transistor is connected to in-vehicle software, the emitter of the first transistor is connected to the collector of a second transistor, the base of the second transistor is connected to a second resistor and a third resistor, and the second resistor is connected to a key ignition switch; An NMOS transistor, wherein the gate of the NMOS transistor is connected to the first transistor, the drain of the NMOS transistor is connected to the auxiliary power module, the auxiliary power module is connected to the second resistor, and the auxiliary power module is used to drive the controller to work; An inductor L, one end of which is connected to the source (S) terminal of the NMOS transistor, and the other end of which is connected to the battery pack.

[0006] As a further description of the above technical solution: the second resistor and the second transistor are connected in parallel with the inductor L, the emitter of the second transistor is grounded, and one end of the third resistor is grounded.

[0007] As a further description of the above technical solution: a first diode is provided between the battery pack and the first resistor and the inductor L, the P terminal of the first diode is connected to the battery pack, and the N terminal of the first diode is connected to the first resistor and the inductor L.

[0008] As a further description of the above technical solution: a second diode is provided between the second resistor and the key ignition switch, the P terminal of the second diode is connected to the key ignition switch, and the N terminal of the second diode is connected to the second resistor.

[0009] As a further description of the above technical solution: an NTC resistor is provided between the second resistor and the NMOS transistor and the auxiliary power supply module.

[0010] As a further description of the above technical solution: the key ignition switch is connected to one end of the fourth resistor, and the fourth resistor is connected in parallel with the second diode.

[0011] As a further description of the above technical solution: the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is grounded.

[0012] As a further description of the above technical solution: a key ignition switch voltage sampling interface is provided between the fourth resistor and the fifth resistor.

[0013] As a further description of the above technical solution: both the first transistor and the second transistor are NPN type transistors.

[0014] The above technical solution has the following advantages or beneficial effects: 1. This invention monitors the voltage of the ignition switch when it is closed, and raises the "power-off maintenance enable" signal in the vehicle software to turn on the first transistor. After power-on, the second transistor is turned on by the voltage division of the second and third resistors, thus turning off the NMOS transistor. At this time, it is in normal working condition. When the ignition switch circuit is unexpectedly de-energized, the second transistor is turned off, and the battery voltage flows through the first resistor to turn on the NMOS transistor. The battery voltage flows through the inductor L for filtering, and then through the NMOS transistor and the NTC resistor to continuously supply power to the auxiliary power module. This can prevent the vehicle from losing control due to the disconnection of the ignition switch circuit.

[0015] 2. The present invention prevents the battery pack voltage from flowing to the key ignition switch voltage sampling interface by using a second diode, thus avoiding the software's inability to determine whether the key ignition switch 7 circuit has been accidentally de-energized, and prevents the key ignition switch 7 voltage from flowing to the battery pack by using a first diode.

[0016] 3. This invention connects to the key ignition switch 7 via the fourth and fifth resistors. By checking the voltage sampling interface of the key ignition switch, it can detect whether the key ignition switch circuit is de-energized. When the in-vehicle software detects that the voltage of the key ignition switch 7 is 0V through the key ignition switch voltage sampling interface, if the vehicle is running and has speed, it will perform emergency braking and report the "key ignition circuit disconnected" fault information to the instrument panel to remind the driver and improve safety. Attached Figure Description

[0017] Figure 1 This is a circuit diagram of an embodiment of the active safety control system for power failure according to the present invention.

[0018] Legend: 1. Battery pack; 2. First resistor; 3. First transistor; 4. Second transistor; 5. Second resistor; 6. Third resistor; 7. Key ignition switch; 8. NMOS transistor; 9. Auxiliary power module; 10. Inductor L; 11. First diode; 12. Second diode; 13. NTC resistor; 14. Fourth resistor; 15. Fifth resistor; 16. Key ignition switch voltage sampling interface. Detailed Implementation

[0019] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: like Figure 1 As shown, a power failure active safety control system of the present invention includes a battery pack 1, which is connected to a first resistor 2. The first resistor 2 is connected to the collector of a first transistor 3, the base of the first transistor 3 is connected to in-vehicle software, the emitter of the first transistor 3 is connected to the collector of a second transistor 4, the base of the second transistor 4 is connected to a second resistor 5 and a third resistor 6, and the second resistor 5 is connected to a key ignition switch 7; an NMOS transistor 8, whose gate (G) is connected to the first transistor 3, and whose drain (D) is connected to an auxiliary power module 9. The auxiliary power module 9 is connected to the second resistor 5 and is used for... The drive controller operates; inductor L10, one end of which is connected to the source (S) terminal of NMOS transistor 8, and the other end of which is connected to battery pack 1; by controlling the auxiliary power module 9, the drive controller operates. Two circuits are implemented through NMOS transistor 8: one is that when the ignition switch 7 is closed, NMOS transistor 8 does not operate, and the auxiliary power module 9 drives the drive controller to operate, which is the normal operating state; the other is that when the ignition switch 7 circuit is unexpectedly de-energized, NMOS transistor 8 controls the auxiliary power 9 to operate, which can prevent the vehicle from losing control due to the disconnection of the ignition switch circuit.

[0021] like Figure 1 As shown, furthermore, NMOS transistor 8 is an NMOS transistor, and both the first transistor 3 and the second transistor 4 are NPN transistors. An NTC resistor 13 is provided between the second resistor 5 and NMOS transistor 8 and the auxiliary power supply module 9. NMOS is an N-type metal-oxide semiconductor. On a P-type silicon substrate with a low doping concentration (providing a large number of movable holes), two highly doped N+ regions are fabricated (the N+ regions contain a large number of electron sources that provide free electrons for current flow), and two electrodes are led out with aluminum metal, serving as the drain (D) and source (S), respectively. Then, a very thin silicon dioxide (SiO2) insulating layer is covered on the semiconductor surface, and an aluminum electrode (usually polysilicon) is mounted on the insulating layer between the drain and source as the gate (G). An electrode B is also led out on the substrate, thus forming an N-channel enhancement-mode MOSFET. The source and substrate of the MOSFET are usually connected together (most transistors are pre-connected at the factory), and its gate is insulated from other electrodes. The resistance of the NTC thermistor 13 decreases as the temperature increases. This characteristic can be used to make temperature measurement, temperature compensation, and temperature control components, as well as power components to suppress inrush current in circuits. This is because the NTC thermistor has a rated zero-power resistance value. When it is connected in series in the power supply circuit, it can effectively suppress the start-up inrush current. After suppressing the inrush current, the resistance of the NTC thermistor decreases to a very small degree due to the continuous effect of the current.

[0022] like Figure 1 As shown, a second diode 12 is disposed between the second resistor 5 and the key ignition switch 7. The P-terminal of the second diode 12 is connected to the key ignition switch 7, and the N-terminal of the second diode 12 is connected to the second resistor 5. An NTC resistor 13 is disposed between the second resistor 5, the NMOS transistor 8, and the auxiliary power module 9. The base of the first transistor 3 is connected to the in-vehicle software at the "power-off sustain enable" signal terminal. By closing the key ignition switch 7, the voltage of the key ignition switch is monitored. The in-vehicle software raises the "power-off sustain enable" signal, turning on the first transistor 3. After power-on, the second transistor 4 is turned on by the voltage division effect of the second resistor 5 and the third resistor 6, thereby turning off the NMOS transistor 8. In this state, the current from battery pack 1 passes through the first resistor 2, the first transistor 3, the second transistor 4, the second resistor 5, and the NTC resistor 13 in sequence to control the auxiliary power supply 9. When the ignition switch line 7 is unexpectedly de-energized, the second transistor 4 is in the off state. The voltage flow from battery pack 1 passes through the first resistor 2 to turn on the NMOS transistor 8. After the voltage flow from battery pack 1 is filtered by inductor L10, it passes through the NMOS transistor 8 and then through the NTC resistor 13 to continuously supply power to the auxiliary power supply module 9. After the vehicle stops and stabilizes, the software pulls down the power-off maintenance enable signal, turns off the first transistor 3, and the NMOS transistor 8 will also be in the off state, which can prevent the vehicle from losing control due to the disconnection of the ignition switch line.

[0023] Example 2: like Figure 1 As shown, based on Embodiment 1, the present invention provides a technical solution: a second resistor 5 and a second transistor 4 are connected in parallel with an inductor L10, the emitter of the second transistor 4 is grounded, one end of a third resistor 6 is grounded, a first diode 11 is provided between the battery pack 1 and the first resistor 2 and the inductor L10, the P-terminal of the first diode 11 is connected to the battery pack 1, and the N-terminal of the first diode 11 is connected to the first resistor 2 and the inductor L10, a second diode 12 is provided between the second resistor 5 and the key ignition switch 7, the P-terminal of the second diode 12 is connected to the key ignition switch 7, and the N-terminal of the second diode 12 is connected to the second resistor 5; the second diode 12 prevents the voltage of the battery pack 1 from flowing to the voltage sampling interface 16 of the key ignition switch, thus preventing the software from being unable to determine whether the circuit of the key ignition switch 7 has been accidentally de-energized, and the first diode 11 prevents the voltage of the key ignition switch 7 from flowing to the battery pack 1.

[0024] like Figure 1As shown, the ignition switch 7 is connected to one end of the fourth resistor 14, the fourth resistor 14 is connected in parallel with the second diode 12, the fourth resistor 14 is connected to one end of the fifth resistor 15, and the other end of the fifth resistor 15 is grounded. A key ignition switch voltage sampling interface 16 is provided between the fourth resistor 14 and the fifth resistor 15. By connecting the fourth resistor 14 and the fifth resistor 15 to the key ignition switch 7, the presence or absence of voltage at the key ignition switch voltage sampling interface 16 can detect whether the key ignition switch 7 circuit is de-energized. After the vehicle software samples that the voltage of the key ignition switch 7 is 0V through the key ignition switch voltage sampling interface 16, if the vehicle is running and has speed, it will perform emergency braking and report the "key ignition circuit disconnected" fault information to the instrument panel to remind the driver and improve safety.

[0025] Working principle: The operator controls the auxiliary power module 9 to drive the drive controller. Two circuits are implemented via NMOS transistor 8: In one normal operation, when the ignition switch 7 is closed, NMOS transistor 8 is inactive, and the auxiliary power module 9 drives the drive controller; in the other operation, if the ignition switch 7 circuit is unexpectedly de-energized, NMOS transistor 8 controls the auxiliary power module 9 to operate, preventing vehicle loss of control due to a disconnected ignition switch circuit. The auxiliary power module 9 is connected to the ignition switch 7 via resistors 14 and 15, and is powered by the ignition switch circuit. The presence of voltage at the voltage sampling interface 16 can detect whether the ignition switch 7 circuit is de-energized. If the vehicle software detects a 0V voltage at the ignition switch 7 via the voltage sampling interface 16, and the vehicle is in motion with speed, it will perform emergency braking and report a "key ignition circuit disconnected" fault message to the instrument panel to alert the driver and improve safety. The second diode 12 prevents voltage from flowing from the battery pack 1 to the voltage sampling interface 16, thus preventing the software from being unable to determine whether the ignition switch 7 circuit has been unexpectedly de-energized. The first diode 11 prevents voltage from flowing from the ignition switch 7 to the battery pack 1.

[0026] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power failure active safety control system for electric forklifts, characterized in that: Includes a battery pack (1), the battery pack (1) is connected to a first resistor (2), the first resistor (2) is connected to the collector of a first transistor (3), the base of the first transistor (3) is connected to in-vehicle software, the emitter of the first transistor (3) is connected to the collector of a second transistor (4), the base of the second transistor (4) is connected to a second resistor (5) and a third resistor (6), and the second resistor (5) is connected to a key ignition switch (7); NMOS transistor (8), the gate of the NMOS transistor (8) is connected to the first transistor (3), the drain of the NMOS transistor (8) is connected to the auxiliary power module (9), the auxiliary power module (9) is connected to the second resistor (5), and the auxiliary power module (9) is used to drive the controller to work. Inductor L (10), one end of which is connected to the source (S) terminal of the NMOS transistor (8), and the other end of which is connected to the battery pack (1); A first diode (11) is provided between the battery pack (1), the first resistor (2), and the inductor L (10). The P terminal of the first diode (11) is connected to the battery pack (1), and the N terminal of the first diode (11) is connected to the first resistor (2) and the inductor L (10). When the key ignition switch (7) is closed, the NMOS transistor (8) does not work, and the auxiliary power module (9) is driven by the key ignition switch (7) to drive the drive controller. Another method is that after the key ignition switch (7) circuit is accidentally de-energized, the NMOS transistor (8) controls the auxiliary power module (9) to work, which can prevent the vehicle from losing control due to the key ignition switch circuit being disconnected.

2. The active safety control system for power failure according to claim 1, characterized in that: The second resistor (5) and the second transistor (4) are connected in parallel with the inductor L (10), the emitter of the second transistor (4) is grounded, and one end of the third resistor (6) is grounded.

3. The active safety control system for power failure according to claim 1, characterized in that: A second diode (12) is provided between the second resistor (5) and the key ignition switch (7). The P terminal of the second diode (12) is connected to the key ignition switch (7), and the N terminal of the second diode (12) is connected to the second resistor (5).

4. The active safety control system for power failure according to claim 1, characterized in that: An NTC resistor (13) is provided between the second resistor (5) and the NMOS transistor (8) and the auxiliary power module (9).

5. The active safety control system for power failure according to claim 1, characterized in that: The key ignition switch (7) is connected to one end of the fourth resistor (14), and the fourth resistor (14) is connected in parallel with the second diode (12).

6. The active safety control system for power failure according to claim 5, characterized in that: The fourth resistor (14) is connected to one end of the fifth resistor (15), and the other end of the fifth resistor (15) is grounded.

7. The active safety control system for power failure according to claim 6, characterized in that: A key ignition switch voltage sampling interface (16) is provided between the fourth resistor (14) and the fifth resistor (15).

8. The active safety control system for power failure according to claim 1, characterized in that: Both the first transistor (3) and the second transistor (4) are NPN type transistors.

Images