Excavator controller and program protection method thereof

Abstract

The invention discloses an excavator controller and a program protection method thereof. The controller comprises a PCB integrated with a microswitch, a processor and a communication interface. A trigger point of the microswitch is higher than the surface of the PCB, and the shell is pressed to be closed when being assembled; the processor is used for detecting switch states; when it is continuously detected that the switch is switched off, it is judged that the shell is detached, specific data in a program storage area is modified immediately to achieve program locking, and the output power of an engine is reduced; and the locked program cannot run in the local machine and also fails when being copied to other processors. An instruction is sent by a special unlocking tool through a communication interface, so that the modified program data can be recovered, and the controller is recovered to be normal; according to the method, full-link protection from physical detection, active locking to safety recovery is achieved, the controller program is effectively prevented from being illegally stolen or tampered, and the method has high reliability, high safety and maintainability.

Description

Technical Field

[0001] This invention relates to an excavator controller and its program protection method, belonging to the field of electronic control technology for construction machinery. Background Technology

[0002] The excavator controller is the core control unit of the entire machine, storing key programs and data such as engine speed regulation algorithms and hydraulic system control logic. Once the controller is illegally disassembled, its internal programs may be read, copied, or tampered with, posing significant safety and economic risks to equipment manufacturers and users.

[0003] Existing protection methods have the following drawbacks: External mechanical switches rely on wire connections, which are easily cut or short-circuited, and are complex to assemble; Software encryption alone cannot defend against physical attacks; the firmware can be read simply by desoldering the processor. Lacking anti-interference design adapted to the vibration and impact conditions of excavators, it is prone to accidental locking due to environmental factors.

[0004] The aforementioned defects can easily expose excavator controllers to the risk of malicious disassembly and program theft. There is an urgent need for a controller protection solution that can detect disassembly behavior at the physical level, quickly trigger program self-locking, and support secure authorization recovery. Summary of the Invention

[0005] The purpose of this invention is to provide an excavator controller and its program protection method, which uses microswitches embedded in the PCB board to detect disassembly, achieving full-link protection of "physical detection, rapid locking, and safe unlocking".

[0006] To achieve the above objectives / to solve the above technical problems, the present invention is implemented using the following technical solution.

[0007] On one hand, the present invention provides an excavator controller, comprising: A PCB board, wherein at least one micro switch is integrated on the PCB board, and the trigger point of the micro switch is higher than the surface of the PCB board, for detecting the assembly state of the controller housing based on the pressure state of the trigger point; The processor, mounted on the PCB board and electrically connected to the micro switch, is used to perform a program locking operation according to the state of the micro switch to lock the processor, thereby making the controller unusable. A communication interface, connected to the processor, is used to interact with an external unlocking tool to unlock and activate the locked processor; The assembly state includes: when the pressure structure on the controller housing presses on the trigger point, the micro switch closes; when the housing is disassembled, the trigger point is not pressed, and the micro switch opens.

[0008] Furthermore, there are four microswitches, which are distributed at diagonal positions on the edge of the PCB board. Each microswitch is connected to the GPIO port of the processor through an OR gate logic circuit, ensuring that a detection signal is triggered when any microswitch is released.

[0009] Furthermore, the micro switch is a normally open switch, and its switching signal circuit includes a pull-up resistor; when the controller housing is assembled, the processor's GPIO port detects a high level; when the controller housing is disassembled, the processor's GPIO port detects a low level.

[0010] Furthermore, the communication interface is a serial communication interface.

[0011] Furthermore, the processor is configured to: when it determines that the housing has been disassembled based on the microswitch status, modify specific data in its program storage area to lock the program, and output a control signal to reduce the output power of the excavator engine.

[0012] In a second aspect, the present invention provides a program protection method for an excavator controller, applied to the excavator controller described in the first aspect, the program protection method comprising: The controller periodically samples the level state of the micro switch connected to the GPIO port; When the controller does not receive a disassembly authorization command and samples the level indicating that the micro switch is open multiple times in a row, it is determined that the controller housing has been disassembled. In response to the determination that the controller housing has been disassembled, the processor modifies specific data in its program storage area to achieve program locking, and sends an instruction to the excavator engine control unit to reduce the engine output power, causing the whole machine to enter an abnormal working mode. The program locked in this way will not be able to start or run after the processor is powered on again, and even if it is completely copied to another controller, it will not be able to run because its integrity has been compromised.

[0013] Furthermore, the sampling period is 5 to 20 milliseconds.

[0014] Furthermore, the method for determining whether the controller housing has been disassembled is as follows: if the micro switch is sampled to a low level three times consecutively, it is determined that the controller housing has been disassembled.

[0015] Furthermore, the unlocking steps after the program is locked specifically include: Power on the processor again; The communication interface sequentially receives handshake commands and unlock start commands from the unlocking tool; In response to the start-unlock command, the specific data modified in the program storage area is restored to its original state; The processor performs a reset operation to restore normal operation.

[0016] Furthermore, the communication interface sequentially receives a handshake command and an unlocking start command from the unlocking tool, specifically including: If the processor recognizes the correct handshake command sent by the unlocking tool, the processor enters unlocking mode and waits for the unlocking command to be initiated. If the processor does not recognize the correct handshake command sent by the unlocking tool, the processor remains locked.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention achieves physical anti-tamper detection through a micro switch integrated into the PCB board, eliminating the hidden danger of external wires being easily damaged; illegal disassembly directly triggers the program's self-destruct lock, so even if the storage processor is removed and read, the obtained program is invalid.

[0018] This invention employs multi-microswitch or gate detection and multiple sampling judgment logic, and optimizes the mechanical structure (such as trigger point height and pressure column material) for excavator vibration conditions, effectively avoiding false triggering caused by environmental vibration.

[0019] This invention introduces a dedicated authorization unlocking mechanism, which enables program recovery through a dedicated unlocking tool and a secure authorization process, ensuring the feasibility of normal repair and maintenance. Attached Figure Description

[0020] Figure 1 This is a hardware structure block diagram of the excavator controller in an embodiment of the present invention; Figure 2 This is a schematic diagram of the layout of the micro switch on the PCB and the OR gate circuit connection. Figure 3 This is a flowchart of the locking triggering process in the program protection method of the present invention; Figure 4 This is a flowchart of the authorization unlocking process in the program protection method of this invention. Detailed Implementation

[0021] It should be noted that: The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0022] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Example

[0023] like Figure 1 As shown in one embodiment, this embodiment provides an excavator controller, including: PCB board 1 integrates four microswitches 2, distributed at the four corners of the edge of PCB board 1. Simultaneously, four pressure posts 4 are respectively located between the upper cover 3 and the microswitches 2, used to detect whether the four corners of the outer casing are open. The trigger point of the microswitches 2 is higher than the surface of PCB board 1, used to detect the assembly state of the controller outer casing based on the pressure state of the trigger point. The pressure posts 4 are located between the upper cover 3 and the microswitches 2, used to press the microswitches 2 when the upper cover 3 and lower cover 5 are closed, causing them to be in a closed state. In this state, the processor 6 detects that the switch is closed, indicating that the outer casing has not been opened. The processor 6 is mounted on the PCB board 1 and electrically connected to the micro switch 2. It is used to perform a program locking operation according to the state of the micro switch 2 to lock the processor 6, thereby making the controller unusable. A communication interface, connected to the processor 6, is used to interact with an external unlocking tool to unlock and activate the locked processor 6; the communication interface is a serial communication interface.

[0024] The assembly state includes: when the pressure structure on the controller housing presses the trigger point, the micro switch 2 closes, and the pressure structure is a pressure column 4 disposed between the housing cover 3 and the micro switch 2; When the housing is removed, the trigger point is not under pressure, and the micro switch 2 is disconnected.

[0025] like Figure 2 As shown, four microswitches SM1, SM2, SM3, and SM4 are connected to the processor's GPIO port through an OR gate logic circuit, ensuring that a detection signal is triggered when any one of the microswitches is released.

[0026] The micro switch is a normally open switch, and its switching signal circuit includes a pull-up resistor; when the controller housing is assembled, the processor's GPIO port detects a high level; when the controller housing is disassembled, the processor's GPIO port detects a low level.

[0027] The processor is configured to: when it determines that the housing has been disassembled based on the state of the microswitch, modify specific data in its program storage area to lock the program, and output a control signal to reduce the output power of the excavator engine.

[0028] The specific data refers to a 16-byte segment of data offset 256 bytes from the starting address of the storage area. The specific data can be generated by encryption using the chip's unique code. If the specific data is modified, it can be rewritten using an unlocking tool (host computer software) to restore the original data. like Figure 3 The embodiment shown provides a program protection method for an excavator controller, applied to the excavator controller of Embodiment 1. The program protection method includes: Under compliant conditions, the controller needs to send a disassembly authorization command to the controller via an unlocking tool to disable the function of detecting the microswitch status. If no authorization command is sent, the processor samples the level status of the microswitch connected to the GPIO port every 10ms. Since when any one of the microswitches at the four corners of the controller is disconnected, the disconnection signal (ground signal) is transmitted to the processor's GPIO port through an OR gate, and the processor can recognize the level change. The unlocking tool can use host computer software and host computer based on serial communication, and the unlocking process is implemented through private data protocol instructions; If the processor samples a low level indicating that the micro switch is open multiple times in a row, it determines that the controller housing has been disassembled. In response to the determination that the controller housing has been disassembled, the processor modifies specific data in its program storage area to achieve program locking, and sends an instruction to the excavator engine control unit to reduce the engine output power, causing the whole machine to enter an abnormal working mode. The program locked in this way will not be able to start or run after the processor is powered on again, and even if it is completely copied to another controller, it will not be able to run because its integrity has been compromised.

[0029] like Figure 4 As shown, the unlocking steps after the program is locked specifically include: Power on the processor again; The communication interface sequentially receives handshake commands and unlock start commands from the unlocking tool; In response to the start-unlock command, the specific data modified in the program storage area is restored to its original state; The processor performs a reset operation to restore normal operation.

[0030] The communication interface sequentially receives handshake instructions and unlock start instructions from the unlocking tool, specifically including: If the processor recognizes the correct handshake command sent by the unlocking tool, the processor enters unlocking mode and waits for the unlocking command to be initiated. If the processor does not recognize the correct handshake command sent by the unlocking tool, the processor remains locked.

[0031] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An excavator controller, characterized in that, include: A PCB board, wherein at least one micro switch is integrated on the PCB board, and the trigger point of the micro switch is higher than the surface of the PCB board, for detecting the assembly state of the controller housing based on the pressure state of the trigger point; The processor, mounted on the PCB board and electrically connected to the micro switch, is used to perform a program locking operation according to the state of the micro switch to lock the processor, thereby making the controller unusable. A communication interface, connected to the processor, is used to interact with an external unlocking tool to unlock and activate the locked processor; The assembly state includes: when the pressure structure on the controller housing presses on the trigger point, the micro switch closes; when the housing is disassembled, the trigger point is not pressed, and the micro switch opens.

2. The excavator controller according to claim 1, characterized in that, The number of microswitches is four, which are distributed at diagonal positions on the edge of the PCB board, and the microswitches are connected to the GPIO port of the processor through an OR gate logic circuit.

3. The excavator controller according to claim 1, characterized in that, The micro switch is a normally open switch, and its switching signal circuit includes a pull-up resistor; when the controller housing is assembled, the processor's GPIO port detects a high level; when the controller housing is disassembled, the processor's GPIO port detects a low level.

4. The excavator controller according to claim 1, characterized in that, The communication interface is a serial communication interface.

5. The excavator controller according to claim 1, characterized in that, The processor is configured to: when it determines that the housing has been disassembled based on the state of the microswitch, modify specific data in its program storage area to lock the program, and output a control signal to reduce the output power of the excavator engine.

6. A program protection method for an excavator controller, applied to the excavator controller as described in any one of claims 1-5, characterized in that, The method includes: The controller periodically samples the level state of the micro switch connected to the GPIO port; When the controller does not receive a disassembly authorization command and samples a level indicating that the micro switch is open several times in a row, it is determined that the controller housing has been disassembled. In response to the determination that the controller housing has been disassembled, the processor modifies specific data in its program storage area to achieve program locking and sends an instruction to the excavator engine control unit to reduce engine output power.

7. The excavator controller program protection method according to claim 6, characterized in that, The sampling period is 5 to 20 milliseconds.

8. The excavator controller program protection method according to claim 6, characterized in that, The method for determining if the controller housing has been disassembled is as follows: if the micro switch is sampled to a low level three times consecutively, it is determined that the controller housing has been disassembled.

9. The excavator controller program protection method according to claim 6, characterized in that, The unlocking steps after the program is locked specifically include: Power on the processor again; The communication interface sequentially receives handshake commands and unlock start commands from the unlocking tool; In response to the start-unlock command, the specific data modified in the program storage area is restored to its original state; The processor performs a reset operation to restore normal operation.

10. The excavator controller program protection method according to claim 6, characterized in that, The communication interface sequentially receives handshake instructions and unlock start instructions from the unlocking tool, specifically including: If the processor recognizes the correct handshake command sent by the unlocking tool, the processor enters unlocking mode and waits for the unlocking command to be initiated. If the processor does not recognize the correct handshake command sent by the unlocking tool, the processor remains locked.

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