A steering control system and method for an excavator loader

Abstract

The application discloses a kind of excavator steering control system and method, steering control system includes processing control unit;When receiving steering mode switching instruction, the front axle alignment detection sensor and rear axle alignment detection sensor collect front axle alignment detection signal and rear axle alignment detection signal;The processing control unit is according to front axle alignment detection signal and rear axle alignment detection signal to the alignment of the front axle and rear axle of excavator, according to steering mode switching instruction switches front wheel steering mode valve, rear wheel steering enable valve, crab steering mode valve and four-wheel steering mode valve;The front wheel steering mode, four-wheel steering mode and crab steering mode of excavator are automatically switched, and the switching process of steering mode is simplified;By the alignment of the front axle and rear axle of excavator, it is favorable to improve the safety of excavator driving.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steering control, and particularly relates to a steering control system and method for a backhoe loader. BACKGROUND

[0002] A backhoe loader is a multifunctional small-sized engineering machine that combines the functions of a traditional excavator and a loader. It can perform shovel loading operation in the loading mode and excavating operation in the excavating mode. This machine is commonly used in space-limited work sites such as construction sites, warehouses, and tunnels, and is widely applied due to its flexibility and multifunctionality.

[0003] However, since the backhoe loader needs to move flexibly in a narrow or crowded environment, the requirements for the steering system are high. Modern backhoe loaders are usually equipped with multiple steering modes, including but not limited to front-wheel steering, four-wheel steering, and crab steering. The front-wheel steering mode is suitable for regular travel and operation, while the four-wheel steering and crab steering modes can provide better maneuverability in narrow spaces. The four-wheel steering mode allows the machine to turn in a smaller radius, and the crab steering mode allows the machine to move laterally without changing the travel direction.

[0004] Although these steering modes improve the flexibility of operation, they also bring control complexity. The operator needs to manually switch different steering modes according to the work environment and requirements, which not only increases the operation difficulty, but also lacks sufficient safety protection measures. SUMMARY

[0005] The purpose of the present application is to provide a steering control system and method for a backhoe loader, aiming to improve the control performance and work safety of small-sized engineering machines through advanced control strategies and automation technology.

[0006] To achieve the above purpose, the technical solution adopted by the present application is:

[0007] In a first aspect, the present application provides a steering control system for a backhoe loader, comprising a processing control unit; the processing control unit is electrically connected to a centering detection unit, an output drive unit, and a control input unit;

[0008] The control input unit is used to receive a steering mode switching instruction; the centering detection unit is electrically connected to a front axle centering detection sensor and a rear axle centering detection sensor; the output drive unit is electrically connected to a front-wheel steering mode valve, a rear-wheel steering enable valve, a crab steering mode valve, and a four-wheel steering mode valve;

[0009] When receiving the steering mode switching instruction, the front axle alignment detection sensor and the rear axle alignment detection sensor collect the front axle alignment detection signal and the rear axle alignment detection signal; the processing control unit aligns the front axle and the rear axle of the excavator loader according to the front axle alignment detection signal and the rear axle alignment detection signal, and switches the front wheel steering mode valve, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve according to the steering mode switching instruction.

[0010] Further, the steering mode of the excavator loader includes a four-wheel steering mode, a crab steering mode and a front wheel steering mode; the control input unit includes a four-wheel steering mode input port and a crab steering mode input port;

[0011] When the four-wheel steering mode input port is turned on, the control input unit receives the steering mode switching instruction as a four-wheel steering mode switching instruction;

[0012] When the crab steering mode input port is turned on, the control input unit receives the steering mode switching instruction as a crab steering mode switching instruction;

[0013] When the four-wheel steering mode input port and the crab steering mode input port are in an off state; the control input unit receives the steering mode switching instruction as a front wheel steering mode switching instruction.

[0014] Further, the output driving unit includes an MCU microprocessor, a first double-contact relay and a second double-contact relay; the MCU microprocessor is electrically connected to the coil of the first double-contact relay through a first relay control circuit; the MCU microprocessor is electrically connected to the coil of the second double-contact relay through a second relay control circuit;

[0015] The moving contact of the first double-contact relay is connected to a power supply, the first stationary contact of the first double-contact relay is electrically connected to a front wheel steering mode valve, and the second stationary contact of the first double-contact relay is electrically connected to a rear wheel steering mode valve;

[0016] The moving contact of the second double-contact relay is electrically connected to the second stationary contact of the first double-contact relay; the first stationary contact of the second double-contact relay is electrically connected to a crab steering mode valve, and the second stationary contact of the second double-contact relay is electrically connected to a four-wheel steering mode valve.

[0017] Further, the output driving unit includes an MCU microprocessor and a steering switching unit; a power supply is electrically connected to a front wheel steering mode valve, a rear wheel steering enable valve, a crab steering mode valve and a four-wheel steering mode valve through four steering switching units respectively; the four steering switching units are electrically connected to the MCU microprocessor, and the MCU microprocessor controls the on-off of the steering switching units;

[0018] The steering switching unit comprises an insulated gate type effect tube, a gate driver and a state feedback unit; the source of the insulated gate type effect tube is electrically connected to a power supply; the gate of the insulated gate type effect tube is electrically connected to the gate driver; the drain of the insulated gate type effect tube is electrically connected to a front wheel steering mode valve, a rear wheel steering enable valve, a crab steering mode valve or a four-wheel steering mode valve; the drain of the insulated gate type effect tube is electrically connected to the state feedback unit; and the drain of the insulated gate type effect tube is grounded through a unidirectional diode.

[0019] Further, the output driving unit is electrically connected to a front wheel steering mode indicator, a four-wheel steering mode indicator and a crab steering mode indicator.

[0020] Further, the processing control unit switches the front wheel steering mode valve, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve according to a steering mode switching instruction, and the process comprises:

[0021] in response to receiving a front wheel steering mode switching instruction, the processing control unit controls the front wheel steering mode valve to be turned on, controls the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve to be turned off, and controls the front wheel steering mode indicator to be powered on;

[0022] in response to receiving a four-wheel steering mode switching instruction, the processing control unit controls the rear wheel steering enable valve and the four-wheel steering mode valve to be turned on, controls the front wheel steering mode valve and the crab steering mode valve to be turned off, and controls the four-wheel steering mode indicator to be powered on;

[0023] in response to receiving a crab steering mode switching instruction, the processing control unit controls the rear wheel steering enable valve and the crab steering mode valve to be turned on, controls the front wheel steering mode valve and the four-wheel steering mode valve to be turned off, and controls the crab steering mode indicator to be powered on.

[0024] The second aspect of the present application provides a steering control method of a backhoe loader, comprising:

[0025] in response to receiving a steering mode switching instruction, the front axle alignment detection sensor and the rear axle alignment detection sensor collect front axle alignment detection signals and rear axle alignment detection signals;

[0026] align the front axle and the rear axle of the backhoe loader according to the front axle alignment detection signals and the rear axle alignment detection signals; and switch the front wheel steering mode valve, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve according to the steering mode switching instruction;

[0027] read the vehicle speed and gear information of the backhoe loader, and control the backhoe loader to enter a safety protection mode when the vehicle speed and the gear information meet a predetermined condition.

[0028] Further, the front axle and the rear axle of the excavator loader are centered according to the front axle centering detection signal and the rear axle centering detection signal, and the process includes:

[0029] The rear axle of the excavator loader is determined to be centered according to the rear axle centering detection signal; when the rear axle of the excavator loader is not centered, the front wheel steering mode valve, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve are switched to the four-wheel steering mode, and the front wheel and the rear wheel are controlled to steer through the steering wheel of the excavator loader until the rear axle is centered;

[0030] The front axle of the excavator loader is determined to be centered according to the front axle centering detection signal; when the front axle of the excavator loader is not centered, the front wheel steering mode valve, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve are switched to the front wheel steering mode, and the front wheel is controlled to steer through the steering wheel of the excavator loader until the front axle is centered.

[0031] Further, the front wheel steering mode valve, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve are switched according to the steering mode switching instruction, and the process includes:

[0032] The output driving unit is electrically connected with a front wheel steering mode indicator light, a four-wheel steering mode indicator light and a crab steering mode indicator light;

[0033] In response to receiving a front wheel steering mode switching instruction; the front wheel steering mode valve is controlled to be turned on, the rear wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve are controlled to be turned off; and the front wheel steering mode indicator light is powered on;

[0034] In response to receiving a four-wheel steering mode switching instruction; the rear wheel steering enable valve and the four-wheel steering mode valve are controlled to be turned on, the front wheel steering mode valve and the crab steering mode valve are controlled to be turned off; and the four-wheel steering mode indicator light is powered on;

[0035] In response to receiving a crab steering mode switching instruction; the rear wheel steering enable valve and the crab steering mode valve are controlled to be turned on, the front wheel steering mode valve and the four-wheel steering mode valve are controlled to be turned off; and the crab steering mode indicator light is powered on.

[0036] Further, it further includes: when the excavator loader is in a safety protection mode, determining the steering mode of the excavator loader;

[0037] When the excavator loader is in the front wheel steering mode, the four-wheel steering mode and the crab steering mode are prohibited to be switched;

[0038] When the excavator-loader is in the four-wheel steering mode or the crab steering mode, it is judged whether the rear axle of the excavator-loader is centered; if the rear axle of the excavator-loader is centered, the excavator-loader is switched to the front-wheel steering mode, and the switching of the four-wheel steering mode and the crab steering mode is prohibited; if the rear axle of the excavator-loader is not centered, the gear and the speed of the excavator-loader are limited.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] The present application collects the front-axle centering detection signal and the rear-axle centering detection signal through the front-axle centering detection sensor and the rear-axle centering detection sensor; the front axle and the rear axle of the excavator-loader are centered according to the front-axle centering detection signal and the rear-axle centering detection signal; the front-wheel steering mode valve, the rear-wheel steering enable valve, the crab steering mode valve and the four-wheel steering mode valve are switched according to the steering mode switching instruction; the front-wheel steering mode, the four-wheel steering mode and the crab steering mode of the excavator-loader are automatically switched, which simplifies the switching process of the steering mode; the front axle and the rear axle of the excavator-loader are automatically centered, which is beneficial to improve the safety of the driving of the excavator-loader.

[0041] The present application reads the speed and gear information of the excavator-loader, controls the excavator-loader to enter the safety protection mode according to the speed and gear information reaching the limiting condition, and automatically switches the excavator-loader to the front-wheel steering mode or limits the gear and speed of the excavator-loader; the excavator-loader can be automatically switched to the front-wheel steering mode at high speed or at an inappropriate gear, which reduces the safety risk caused by improper operation. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1 is a structure diagram of the steering control system of the excavator-loader provided in Embodiment 1;

[0043] Fig. 2 is a structure diagram of the output driving unit provided in Embodiment 1;

[0044] Fig. 3 is a structure diagram of the output driving unit provided in Embodiment 2;

[0045] Fig. 4 is a flow chart of the steering control method of the excavator-loader provided in Embodiment 3;

[0046] Fig. 5 is a flow chart of controlling the excavator-loader to enter the safety protection mode provided in Embodiment 3.

[0047] In the figure, 1 is a processing control unit, 2 is a centering detection unit, 3 is an output drive unit, 4 is a control input unit, 5 is a communication interface, 6 is a power supply, 7 is a first double-contact relay, 8 is a first relay control circuit, 9 is a second double-contact relay, 10 is an MCU microprocessor, 11 is a second relay control circuit, 12 is a four-wheel steering mode valve, 13 is a diagonal steering mode valve, 14 is a rear-wheel steering enable valve, 15 is a front-wheel steering mode valve, 16 is a gate driver, 17 is a state feedback unit, 18 is an insulated gate effect transistor, and 19 is a unidirectional diode. DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] It should be noted that, in the description of the present invention, the terms "front," "rear," "left," "right," "up," "down," "inside," and "outside" and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are intended solely to facilitate the description of the present invention and do not require that the present invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "front," "rear," "left," "right," "up," and "down" used in the description of the present invention refer to directions in the accompanying drawings, and the terms "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0050] Example 1

[0051] like Figs. 1-2 As shown, a steering control system of an excavator loader includes a processing control unit 1; the processing control unit 1 is connected to the host computer through a communication interface; the processing control unit 1 is electrically connected to a centering detection unit 2, an output drive unit 3 and a control input unit 4; the centering detection unit 2, the output drive unit 3 and the control input unit 4 are integrated to improve the integration and modularity of the steering control system, thereby enhancing the overall reliability.

[0052] The control input unit 4 is used to receive a steering mode switching instruction; the steering modes of the backhoe loader include a four-wheel steering mode, a tilt steering mode and a front-wheel steering mode; the control input unit 4 includes a four-wheel steering mode input port and a tilt steering mode input port;

[0053] When the four-wheel steering mode input port is connected, the control input unit 4 receives a steering mode switching instruction which is a four-wheel steering mode switching instruction;

[0054] When the oblique steering mode input port is connected, the steering mode switching instruction received by the control input unit 4 is an oblique steering mode switching instruction;

[0055] When the four-wheel steering mode input port and the crab steering mode input port are in the off state; the control input unit 4 receives a steering mode switching instruction as a front-wheel steering mode switching instruction.

[0056] The output drive unit 3 includes an MCU microprocessor 10, a first double-contact relay 7 and a second double-contact relay 9; the MCU microprocessor 10 is electrically connected to the coil of the first double-contact relay 7 through a first relay control circuit 8; the MCU microprocessor 10 is electrically connected to the coil of the second double-contact relay 9 through a second relay control circuit 11;

[0057] The moving contact of the first double-contact relay 7 is connected to the power supply, the first stationary contact of the first double-contact relay 7 is electrically connected to the front-wheel steering mode valve, and the second stationary contact of the first double-contact relay 7 is electrically connected to the rear-wheel steering mode valve;

[0058] The moving contact of the second double-contact relay 9 is electrically connected to the second stationary contact of the first double-contact relay 7; the first stationary contact of the second double-contact relay 9 is electrically connected to the crab steering mode valve, and the second stationary contact of the second double-contact relay 9 is electrically connected to the four-wheel steering mode valve; ensuring that the crab steering mode valve or the four-wheel steering mode valve can only be turned on under the premise of turning on the rear-wheel steering mode valve, thereby increasing the safety and reliability of the control system

[0059] At the same time, the output drive unit is electrically connected with a front-wheel steering mode indicator light, a four-wheel steering mode indicator light and a crab steering mode indicator light; the centering detection unit is electrically connected with a front axle centering detection sensor and a rear axle centering detection sensor.

[0060] The control input unit receives a steering mode switching instruction and sends it to the processing control unit, the front axle centering detection sensor and the rear axle centering detection sensor collect front axle centering detection signals and rear axle centering detection signals, and send the front axle centering detection signals and the rear axle centering detection signals to the processing control unit 1; the processing control unit 1 centers the front axle and the rear axle of the excavator according to the front axle centering detection signals and the rear axle centering detection signals.

[0061] The processing control unit 1 switches the front-wheel steering mode valve 15, the rear-wheel steering enable valve 14, the crab steering mode valve 13 and the four-wheel steering mode valve 12 according to the steering mode switching instruction, and the process includes:

[0062] In response to receiving a front-wheel steering mode switching instruction; the processing control unit controls the front-wheel steering mode valve 15 to be turned on, and controls the rear-wheel steering enable valve 14, the crab steering mode valve 13 and the four-wheel steering mode valve 12 to be turned off; the processing control unit controls the front-wheel steering mode indicator light to be turned on.

[0063] In response to receiving the four-wheel steering mode switching instruction, the processing control unit 1 controls the rear wheel steering enable valve 14 and the four-wheel steering mode valve 12 to be turned on, and controls the front wheel steering mode valve 15 and the oblique steering mode valve 13 to be turned off; the processing control unit controls the four-wheel steering mode indicator light to be powered on;

[0064] In response to receiving the oblique steering mode switching instruction; the processing control unit 1 controls the rear wheel steering enable valve 14 and the oblique steering mode valve 13 to be turned on, and controls the front wheel steering mode valve 15 and the four-wheel steering mode valve 12 to be turned off; the processing control unit controls the oblique steering mode indicator light to be powered on.

[0065] This embodiment automatically switches the front-wheel steering mode, four-wheel steering mode and oblique steering mode of the backhoe loader, thereby simplifying the steering mode switching process; and by automatically aligning the front and rear axles of the backhoe loader, it is beneficial to improve the driving safety of the backhoe loader.

[0066] Example 2

[0067] like Figs. 1-3 As shown, a steering control system of an excavator loader includes a processing control unit 1; the processing control unit 1 is electrically connected to a centering detection unit 2, an output drive unit 3 and a control input unit 4;

[0068] The control input unit 4 is used to receive a steering mode switching instruction; the steering modes of the backhoe loader include a four-wheel steering mode, a tilt steering mode and a front-wheel steering mode; the control input unit 4 includes a four-wheel steering mode input port and a tilt steering mode input port;

[0069] When the four-wheel steering mode input port is connected, the control input unit 4 receives a steering mode switching instruction which is a four-wheel steering mode switching instruction;

[0070] When the oblique steering mode input port is connected, the steering mode switching instruction received by the control input unit 4 is an oblique steering mode switching instruction;

[0071] When the four-wheel steering mode input port and the oblique steering mode input port are in the disconnected state, the steering mode switching instruction received by the control input unit 4 is a front-wheel steering mode switching instruction.

[0072] The output drive unit 3 includes an MCU microprocessor 10 and a steering switching unit; the power supply is electrically connected to the front wheel steering mode valve 15, the rear wheel steering enable valve 14, the oblique steering mode valve 13, and the four-wheel steering mode valve 12 through four steering switching units; the four steering switching units are electrically connected to the MCU microprocessor 10, and the MCU microprocessor 10 controls the on and off of the steering switching units;

[0073] The steering switching unit includes an insulated gate type effect tube 18, a gate driver 16 and a state feedback unit 17; the source of the insulated gate type effect tube 18 is electrically connected to a power supply; the MCU microprocessor 10 is electrically connected to the gate of the insulated gate type effect tube 18 through the gate driver 16; the drain of the insulated gate type effect tube 18 is electrically connected to the front wheel steering mode valve 15, the rear wheel steering enable valve 14, the crab steering mode valve 13 or the four-wheel steering mode valve 12; the MCU microprocessor 10 is electrically connected to the drain of the insulated gate type effect tube 18 through the state feedback unit 17; the drain of the insulated gate type effect tube 18 is grounded through a unidirectional diode 19; the state feedback unit 17 can feed back the electrical state of the corresponding mode execution valve to the MCU microprocessor, realize the detection and fault diagnosis of the state, and increase the safety and reliability of the control system.

[0074] Meanwhile, the output driving unit is electrically connected with a front wheel steering mode indicator light, a four-wheel steering mode indicator light and a crab steering mode indicator light; the centering detection unit is electrically connected with a front axle centering detection sensor and a rear axle centering detection sensor.

[0075] The control input unit 4 receives the steering mode switching instruction and sends it to the processing control unit 1, the front axle centering detection sensor and the rear axle centering detection sensor collect front axle centering detection signals and rear axle centering detection signals, and send the front axle centering detection signals and the rear axle centering detection signals to the processing control unit 1; the processing control unit 1 centers the front axle and the rear axle of the excavator according to the front axle centering detection signals and the rear axle centering detection signals.

[0076] The processing control unit 1 switches the front wheel steering mode valve 15, the rear wheel steering enable valve 14, the crab steering mode valve 13 and the four-wheel steering mode valve 12 according to the steering mode switching instruction, and the process includes:

[0077] In response to receiving the front wheel steering mode switching instruction; the processing control unit controls the front wheel steering mode valve 15 to be turned on, controls the rear wheel steering enable valve 14, the crab steering mode valve 13 and the four-wheel steering mode valve 12 to be turned off; the processing control unit controls the front wheel steering mode indicator light to be powered on;

[0078] In response to receiving the four-wheel steering mode switching instruction; the processing control unit 1 controls the rear wheel steering enable valve 14 and the four-wheel steering mode valve 12 to be turned on, controls the front wheel steering mode valve 15 and the crab steering mode valve 13 to be turned off; the processing control unit controls the four-wheel steering mode indicator light to be powered on;

[0079] In response to receiving the oblique steering mode switching instruction, the processing control unit 1 controls the rear wheel steering enable valve 14 and the oblique steering mode valve 13 to be connected, and controls the front wheel steering mode valve 15 and the four-wheel steering mode valve 12 to be disconnected; the processing control unit controls the oblique steering mode indicator light to be powered on; and switches between the three modes of front wheel steering, four-wheel steering, and oblique steering to adapt to different working environments and needs.

[0080] Example 3

[0081] like Figs. 4-5 As shown, a steering control method for an excavator loader is provided, wherein the steering control method is applied to the steering control system described in Example 1 or Example 2, and includes:

[0082] In response to receiving a steering mode switching instruction, the steering mode switching instruction being the same as the steering mode of the backhoe loader, maintaining the current output drive state;

[0083] In response to the steering mode switching instruction being the same as the steering mode of the backhoe loader, collecting a front axle centering detection signal and a rear axle centering detection signal through a front axle centering detection sensor and a rear axle centering detection sensor;

[0084] The front and rear axles of the backhoe loader are aligned according to the front and rear axle alignment detection signals. The process includes:

[0085] Determine whether the rear axle of the backhoe loader is aligned based on the rear axle alignment detection signal; when the rear axle of the backhoe loader is not aligned, control the rear wheel steering enable valve 14 and the four-wheel steering mode valve 12 to be connected, and control the front wheel steering mode valve 15 and the oblique steering mode valve 13 to be disconnected; turn on the power of the four-wheel steering mode indicator light to switch the backhoe loader to the four-wheel steering mode, and control the front and rear wheel steering through the steering wheel of the backhoe loader until the rear axle is aligned;

[0086] Whether the front axle of the backhoe loader is aligned is determined based on the front axle alignment detection signal; when the front axle of the backhoe loader is not aligned, the front wheel steering mode valve 15 is controlled to be connected, and the rear wheel steering enable valve 14, the oblique steering mode valve 13 and the four-wheel steering mode valve 12 are controlled to be disconnected; the front wheel steering mode indicator light is connected to the power supply to switch the backhoe loader to the front wheel steering mode, and the front wheel steering is controlled by the steering wheel of the backhoe loader until the front axle is aligned.

[0087] The process of switching the front wheel steering mode valve 15, the rear wheel steering enabling valve 14, the oblique steering mode valve 13 and the four-wheel steering mode valve 12 according to the steering mode switching instruction includes:

[0088] In response to receiving the front wheel steering mode switching instruction; the processing control unit 1 controls the front wheel steering mode valve 15 to be turned on, controls the rear wheel steering enable valve 14, the crab steering mode valve 13 and the four wheel steering mode valve 12 to be turned off; the processing control unit controls the front wheel steering mode indicator light to be powered on;

[0089] In response to receiving the four wheel steering mode switching instruction; the processing control unit 1 controls the rear wheel steering enable valve 14 and the four wheel steering mode valve 12 to be turned on, controls the front wheel steering mode valve 15 and the crab steering mode valve 13 to be turned off; the processing control unit controls the four wheel steering mode indicator light to be powered on;

[0090] In response to receiving the crab steering mode switching instruction; the processing control unit 1 controls the rear wheel steering enable valve 14 and the crab steering mode valve 13 to be turned on, controls the front wheel steering mode valve 15 and the four wheel steering mode valve 12 to be turned off; the processing control unit controls the crab steering mode indicator light to be powered on.

[0091] Reading the speed and gear information of the excavator loader, and controlling the excavator loader to enter the safety protection mode according to the speed and gear information reaching the limited condition; judging the steering mode of the excavator loader when the excavator loader is in the safety protection mode;

[0092] When the excavator loader is in the front wheel steering mode, the four wheel steering mode and the crab steering mode are prohibited to be switched;

[0093] When the excavator loader is in the four wheel steering mode or the crab steering mode, judging whether the rear axle of the excavator loader is centered; if the rear axle of the excavator loader is centered, the excavator loader is switched to the front wheel steering mode, and the four wheel steering mode and the crab steering mode are prohibited to be switched; if the rear axle of the excavator loader is not centered, the gear and the speed of the excavator loader are limited; the excavator loader can be automatically switched to the front wheel steering mode at high speed or at inappropriate gear, reducing the safety risk caused by improper operation.

[0094] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A steering control system for an excavator loader, characterized in that: It includes a processing control unit; the processing control unit is electrically connected to the centering detection unit, the output drive unit and the control input unit; The control input unit is used to receive a steering mode switching instruction; the centering detection unit is electrically connected to the front axle centering detection sensor and the rear axle centering detection sensor; the output drive unit is electrically connected to the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve; The output drive unit includes an MCU microprocessor, a first double-contact relay and a second double-contact relay; the MCU microprocessor is electrically connected to the coil of the first double-contact relay through a first relay control circuit; the MCU microprocessor is electrically connected to the coil of the second double-contact relay through a second relay control circuit; The movable contact of the first double-contact relay is connected to a power source, the first static contact of the first double-contact relay is electrically connected to a front-wheel steering mode valve, and the second static contact of the first double-contact relay is electrically connected to a rear-wheel steering mode valve; The movable contact of the second double-contact relay is electrically connected to the second static contact of the first double-contact relay; the first static contact of the second double-contact relay is electrically connected to the tilt steering mode valve, and the second static contact of the second double-contact relay is electrically connected to the four-wheel steering mode valve; When a steering mode switching instruction is received, the front axle centering detection sensor and the rear axle centering detection sensor collect a front axle centering detection signal and a rear axle centering detection signal; The processing control unit centers the front axle and the rear axle of the backhoe loader according to the front axle centering detection signal and the rear axle centering detection signal, and the process includes: Determine whether the rear axle of the backhoe loader is centered based on the rear axle centering detection signal; when the rear axle of the backhoe loader is not centered, switch to the four-wheel steering mode through the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve, and control the front and rear wheel steering through the steering wheel of the backhoe loader until the rear axle is centered; Determine whether the front axle of the backhoe loader is centered based on the front axle centering detection signal; when the front axle of the backhoe loader is not centered, switch to the front wheel steering mode through the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve, and control the front wheel steering through the steering wheel of the backhoe loader until the front axle is centered; The processing control unit switches the front wheel steering mode valve, the rear wheel steering enable valve, the tilt steering mode valve and the four wheel steering mode valve according to the steering mode switching instruction.

2. The steering control system of the backhoe loader according to claim 1, characterized in that: The steering modes of the backhoe loader include a four-wheel steering mode, a tilt steering mode and a front-wheel steering mode; the control input unit includes a four-wheel steering mode input port and a tilt steering mode input port; When the four-wheel steering mode input port is connected, the steering mode switching instruction received by the control input unit is a four-wheel steering mode switching instruction; When the oblique steering mode input port is connected, the steering mode switching instruction received by the control input unit is an oblique steering mode switching instruction; When the four-wheel steering mode input port and the oblique steering mode input port are in a disconnected state, the steering mode switching instruction received by the control input unit is a front-wheel steering mode switching instruction.

3. The steering control system of the backhoe loader according to claim 1, characterized in that: The output drive unit is electrically connected to a front wheel steering mode indicator light, a four-wheel steering mode indicator light and a diagonal steering mode indicator light.

4. The steering control system of the backhoe loader according to claim 3, characterized in that: The processing control unit switches the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve according to the steering mode switching instruction, and the process includes: In response to receiving a front wheel steering mode switching instruction; the processing control unit controls the front wheel steering mode valve to be turned on, controls the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve to be turned off; the processing control unit controls the front wheel steering mode indicator light to be powered on; In response to receiving a four-wheel steering mode switching instruction, the processing control unit controls the rear wheel steering enable valve and the four-wheel steering mode valve to be turned on, and controls the front wheel steering mode valve and the oblique steering mode valve to be turned off; the processing control unit controls the four-wheel steering mode indicator light to be powered on; In response to receiving the oblique steering mode switching instruction; the processing control unit controls the rear wheel steering enable valve and the oblique steering mode valve to be connected, and controls the front wheel steering mode valve and the four-wheel steering mode valve to be disconnected; the processing control unit controls the oblique steering mode indicator light to be powered on.

5. A steering control system for an excavator loader, characterized in that: It includes a processing control unit; the processing control unit is electrically connected to the centering detection unit, the output drive unit and the control input unit; The control input unit is used to receive a steering mode switching instruction; the centering detection unit is electrically connected to the front axle centering detection sensor and the rear axle centering detection sensor; the output drive unit is electrically connected to the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve; The output drive unit includes an MCU microprocessor and a steering switching unit; the power supply is electrically connected to the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve through four steering switching units; the four steering switching units are electrically connected to the MCU microprocessor, and the MCU microprocessor controls the on and off of the steering switching units; The steering switching unit includes an insulated gate effect transistor, a gate driver, and a state feedback unit; the source of the insulated gate effect transistor is electrically connected to a power supply; the MCU microprocessor is electrically connected to the gate of the insulated gate effect transistor through the gate driver; the drain of the insulated gate effect transistor is electrically connected to the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve, or the four-wheel steering mode valve; the MCU microprocessor is electrically connected to the drain of the insulated gate effect transistor through the state feedback unit; the drain of the insulated gate effect transistor is grounded through a unidirectional diode; When a steering mode switching instruction is received, the front axle centering detection sensor and the rear axle centering detection sensor collect a front axle centering detection signal and a rear axle centering detection signal; The processing control unit centers the front axle and the rear axle of the backhoe loader according to the front axle centering detection signal and the rear axle centering detection signal, and the process includes: Determine whether the rear axle of the backhoe loader is centered based on the rear axle centering detection signal; when the rear axle of the backhoe loader is not centered, switch to the four-wheel steering mode through the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve, and control the front and rear wheel steering through the steering wheel of the backhoe loader until the rear axle is centered; Determine whether the front axle of the backhoe loader is centered based on the front axle centering detection signal; when the front axle of the backhoe loader is not centered, switch to the front wheel steering mode through the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve, and control the front wheel steering through the steering wheel of the backhoe loader until the front axle is centered; The processing control unit switches the front wheel steering mode valve, the rear wheel steering enable valve, the tilt steering mode valve and the four wheel steering mode valve according to the steering mode switching instruction.

6. The steering control method of a steering control system according to any one of claims 1 to 5, characterized in that: include: In response to receiving the steering mode switching instruction, collecting a front axle centering detection signal and a rear axle centering detection signal via a front axle centering detection sensor and a rear axle centering detection sensor; Align the front and rear axles of the excavator loader according to the front axle centering detection signal and the rear axle centering detection signal; switch the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve according to the steering mode switching instruction; The vehicle speed and gear information of the backhoe loader are read, and the backhoe loader is controlled to enter a safety protection mode according to the vehicle speed and gear information meeting the limited conditions.

7. The steering control method according to claim 6, characterized in that: The front and rear axles of the backhoe loader are aligned according to the front and rear axle alignment detection signals. The process includes: Determine whether the rear axle of the backhoe loader is centered based on the rear axle centering detection signal; when the rear axle of the backhoe loader is not centered, switch to the four-wheel steering mode through the front wheel steering mode valve, the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve, and control the front and rear wheel steering through the steering wheel of the backhoe loader until the rear axle is centered; Whether the front axle of the backhoe loader is aligned is determined based on the front axle alignment detection signal; when the front axle of the backhoe loader is not aligned, the front wheel steering mode valve, rear wheel steering enable valve, oblique steering mode valve and four-wheel steering mode valve are used to switch to the front wheel steering mode, and the front wheel steering is controlled by the steering wheel of the backhoe loader until the front axle is aligned.

8. The steering control method according to claim 6, characterized in that: The front wheel steering mode valve, rear wheel steering enable valve, tilt steering mode valve and four-wheel steering mode valve are switched according to the steering mode switching instruction. The process includes: The output drive unit is electrically connected to a front wheel steering mode indicator light, a four-wheel steering mode indicator light, and a diagonal steering mode indicator light; In response to receiving the front wheel steering mode switching instruction; controlling the front wheel steering mode valve to be turned on, controlling the rear wheel steering enable valve, the oblique steering mode valve and the four-wheel steering mode valve to be turned off; and turning on the front wheel steering mode indicator light; In response to receiving a four-wheel steering mode switching instruction; controlling the rear wheel steering enable valve and the four-wheel steering mode valve to be turned on, controlling the front wheel steering mode valve and the oblique steering mode valve to be turned off; and turning on the four-wheel steering mode indicator light; In response to receiving the oblique steering mode switching instruction; controlling the rear wheel steering enable valve and the oblique steering mode valve to be connected, controlling the front wheel steering mode valve and the four-wheel steering mode valve to be disconnected; and turning on the oblique steering mode indicator light.

9. The steering control method according to claim 6, characterized in that: Also includes: When the backhoe loader is in a safety protection mode, determining the steering mode of the backhoe loader; When the backhoe loader is in front-wheel steering mode, it is prohibited to switch between four-wheel steering mode and oblique steering mode; When the backhoe loader is in the four-wheel steering mode or the oblique steering mode, determine whether the backhoe loader's rear axle is centered; if the backhoe loader's rear axle is centered, switch the backhoe loader to the front-wheel steering mode, and prohibit switching between the four-wheel steering mode and the oblique steering mode; if the backhoe loader's rear axle is not centered, limit the gear and speed of the backhoe loader.

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