Safety braking control system for mining dump trucks based on braking feedback

Abstract

The present invention discloses a safety brake control system for a mining dump truck based on brake feedback, including: a service brake system, which includes front and rear axle hydraulic accumulators, a brake pedal, a service brake solenoid valve, an emergency brake solenoid valve, and front and rear axle brakes; a parking brake system, which includes a parking hydraulic accumulator, a parking brake solenoid valve, and a parking brake; a pressure feedback system, including a pressure switch and a pressure sensor; a fault detection and diagnosis module, which performs a safety action and confirms the fault location and cause according to the pressure switch signal and the pressure value. The present invention overcomes the problem that the existing mining dump truck brake control system cannot intelligently detect and terminal brake system failures. By setting a pressure sensor and a pressure switch, the comprehensive monitoring of the braking process and intelligent fault detection and analysis are realized based on the pressure feedback data, and a safety action is performed in the event of a fault, thereby improving the braking performance, safety, and operating efficiency of the mining dump truck.

Description

Technical Field

[0001] The invention relates to the technical field of dump truck braking, and in particular to a safety braking control system for a mining dump truck based on braking feedback. Background Art

[0002] In the mining environment, mining dump trucks, as key transportation equipment, undertake heavy material transportation tasks. Such vehicles usually operate in complex and changeable terrain and harsh working conditions, such as steep slopes, muddy roads and gravel-covered roads, which place extremely high demands on their braking systems. Traditional mining dump truck braking systems often rely on mechanical or simple hydraulic braking methods. These systems may have problems such as slow braking response, insufficient braking force, and wear of brake components when dealing with emergency braking, parking braking, and long-term high-intensity braking, which in turn affects the safety, stability and operating efficiency of the vehicle.

[0003] Especially during the braking process, if there is a lack of an effective feedback mechanism, the driver may not be able to accurately judge the actual working status of the braking system, which may lead to brake failure and increase the risk of vehicle loss of control and accidents. Chinese Patent Announcement No. CN211995523U, published on November 24, 2020, entitled "A Heavy-Duty Mining Dump Truck Pneumatic Braking System" discloses a braking system for a mining dump truck, which consists of a service braking system, a parking brake system, and an auxiliary air system. The steering pump stores energy in the supplementary accumulator to achieve a backup replacement of the braking hydraulic energy source to improve the reliability and flexibility of the braking system. However, due to the lack of an intelligent fault detection and diagnosis module, once a fault occurs, it is necessary to rely on manual troubleshooting, which is not only time-consuming and labor-intensive, but may also delay repairs due to inaccurate and incomplete diagnosis, further affecting work progress and vehicle safety.

[0004] Therefore, it is particularly important to develop a safe braking control system for mining dump trucks that can monitor the braking system status in real time and has the ability to self-check and diagnose faults. The system needs to be able to quickly locate the fault point and determine the fault type based on the feedback information during the braking process when a fault occurs, so as to take timely measures to ensure the safe operation of the vehicle. In view of the special working environment and complex braking requirements of mining dump trucks, the current braking control system still has obvious deficiencies in the optimization of braking performance, the timeliness of fault warning, and the intelligence of fault judgment. Summary of the invention

[0005] The present invention overcomes the problems that the existing mining dump truck braking control system cannot perform intelligent detection and terminal braking system failures, and provides a mining dump truck safety braking control system based on braking feedback. By integrating the service braking system, the parking brake system, the pressure feedback system and the fault detection and diagnosis module, and by setting a pressure sensor and a pressure switch, comprehensive monitoring of the braking process and intelligent fault detection and analysis are achieved based on pressure feedback data, thereby improving the braking performance, safety and operating efficiency of the mining dump truck.

[0006] In order to achieve the above object, the present invention adopts the following scheme: A safety braking control system for a mining dump truck based on braking feedback includes: The service brake system includes a front axle hydraulic accumulator, a middle and rear axle hydraulic accumulator, a service brake solenoid valve, an emergency brake solenoid valve, a front axle relay valve, a middle and rear axle relay valve, a front axle brake and a middle and rear axle brake, and is used to control the braking of the vehicle during driving; A parking brake system, including a parking hydraulic accumulator, a parking brake solenoid valve, a backup parking brake solenoid valve and a parking brake, for performing brake control when the vehicle is parked; A pressure feedback system, comprising a pressure switch and a pressure sensor, wherein the pressure switch is arranged on the output circuit of the backup parking brake solenoid valve; a plurality of the pressure sensors are respectively arranged on the output circuit of the front axle hydraulic accumulator, the output circuit of the middle and rear axle hydraulic accumulator, the output circuit of the parking hydraulic accumulator, the output circuit of the service brake solenoid valve, the input circuit of the front axle brake, the input circuit of the middle and rear axle brake, and the input circuit of the parking brake; The fault detection and diagnosis module is configured to determine that it is a brake system fault when the vehicle control unit detects that the pressure switch signal and the pressure sensor feedback pressure value are abnormal, and determine the cause of the fault.

[0007] Preferably, the service brake system further comprises a brake pedal and a brake foot valve, and the service brake system performs service brake control via an independent electric control circuit and a foot valve control circuit; When the electric control circuit receives a feedback signal from an angle sensor disposed in the brake pedal or an external brake request signal through the vehicle control unit, the electric control circuit controls the service brake solenoid valve or the emergency brake solenoid valve to brake the vehicle; The foot valve control circuit controls the front axle relay valve or the middle and rear axle relay valve through the hydraulic response of the foot brake valve when the brake pedal is depressed, so as to control vehicle braking according to the force and speed at which the driver depresses the brake pedal.

[0008] Preferably, the service brake system further comprises a brake pedal; wherein, The brake pedal is provided with a first angle sensor and a second angle sensor, the first angle sensor collects a brake pedal angle signal A1, and the second angle sensor collects a brake pedal angle signal A2; The voltage values ​​of the collected brake pedal angle signals A1 and A2 are respectively subjected to voltage range verification, including: if the voltage value of the collected angle signal is not within a preset normal voltage range, determining that the brake pedal has a signal over-limit fault; Analyze and convert the brake pedal angle signal A1 and the brake pedal angle signal A2 that pass the voltage range check into the corresponding brake pedal opening value; If the voltage multiples of the brake pedal angle signal A1 and the brake pedal angle signal A2 are stable within a set range within a specified time, a larger opening value is output as the effective opening value of the brake pedal; If the voltage multiples of the brake pedal angle signal A1 and the brake pedal angle signal A2 exceed the set range within a specified time, a 100% maximum brake opening is output and a fault message is reported.

[0009] Preferably, the fault detection and diagnosis mechanism includes a parking brake power-on detection mechanism, which operates as follows: In response to a vehicle start signal when a key switch of the vehicle is activated, if the vehicle control unit detects that the parking brake solenoid valve is not in a parking state, the parking brake solenoid valve is controlled to operate, and the driver is prompted to press the parking switch. When it is detected that the driver performs parking and releasing operations, it is determined that the parking brake power-on detection has passed; In response to a vehicle start signal when the vehicle key switch is activated, if the vehicle control unit detects that the parking brake solenoid valve is in the parking state, when the parking pressure switch is disconnected or the pressure value of the parking brake pressure sensor is higher than the normal value of the parking state, it is determined that the parking brake power-on detection has failed, the parking system is abnormal / failed, and fault information is reported.

[0010] Preferably, the service brake system further comprises a brake motor, and the fault detection and diagnosis module comprises an emergency brake power-on detection mechanism, which operates as follows: In response to a vehicle start signal when the vehicle key switch is activated, when the brake motor works for a set time, the emergency brake solenoid valve is energized, and if a short circuit or an open circuit is detected, fault information is reported and driving is prohibited; In response to a vehicle start signal when a key switch of the vehicle is activated, when the brake motor works for a set time, the emergency brake solenoid valve is energized, and no fault is detected, then the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensors are detected; If the pressure value of at least one of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor does not reach the preset normal pressure value, the emergency brake fault type and position are analyzed according to the position of the pressure sensor that does not reach the normal pressure value; otherwise, It is determined that the emergency brake power-on test has passed.

[0011] Preferably, if the front axle brake pressure sensor and the middle and rear axle brake pressure sensor have no faults, but the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor do not reach the preset normal pressure values, the fault diagnosis information is output as an emergency brake power-on detection failure fault, and a second emergency brake power-on detection is performed after a preset time interval, and the following fault diagnosis is performed according to the pressure values ​​of the pressure sensors during the second power-on detection: If the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor both reach the preset normal pressure values, it is determined that the emergency brake power-on detection has passed, and a brake system slow charging fault is output; If the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator and the middle and rear axle hydraulic accumulator pressure sensors reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake execution system fault is output; If the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator and the middle and rear axle hydraulic accumulator pressure sensors do not reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake system filling fault is output; If the pressure value of only one of the front axle brake pressure sensor and the mid-rear axle brake pressure sensor reaches the preset normal pressure value, it is determined that the emergency brake power-on detection has failed, and a brake system fault is output.

[0012] Preferably, if the front axle brake pressure sensor and the middle and rear axle brake pressure sensor have no faults, when the pressure value of one of the pressure sensors does not reach the preset normal pressure value, an emergency brake power-on detection failure fault is output, and a second emergency brake power-on detection is performed after a preset time interval, and the following fault diagnosis is performed according to the pressure value of the pressure sensor during the second detection: If the pressure value of one of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor reaches the preset normal pressure value in the second detection, and the pressure value of the corresponding circuit accumulator pressure sensor is normal, it is determined that the emergency brake power-on detection has not passed, and according to the position of one of the pressure sensors, fault diagnosis information is output: front axle brake pressure fault or middle and rear axle brake pressure fault; If the pressure value of one of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor does not reach the preset normal pressure value in the second detection, and the pressure value of the corresponding circuit accumulator pressure sensor is normal, it is determined that the emergency brake power-on detection has not passed, and according to the position of the pressure sensor that has not passed the power-on detection, fault diagnosis information is output: front axle brake system failure or middle and rear axle brake system failure; If the pressure value of one of the front axle brake pressure sensors and the mid-rear axle brake pressure sensors does not reach the preset normal pressure value in the second detection, and the pressure value of the pressure sensor of the corresponding circuit accumulator does not reach the preset normal pressure value, it is determined that the emergency brake power-on detection has failed, and based on the position of the pressure sensor that has failed the power-on detection, fault diagnosis information is output: front axle brake system failure or mid-rear axle brake system failure.

[0013] Preferably, the vehicle further includes an emergency brake switch and a parking switch, and the process of determining the cause of the fault includes: In response to an emergency brake request signal when the emergency brake switch is pressed, the emergency brake solenoid valve is controlled to be energized and the parking brake solenoid valve is de-energized; if the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensors do not reach a preset pressure value, the fault is diagnosed as a brake system abnormality / failure, and the service brake solenoid valve is controlled to be energized; In response to a parking request signal when the parking switch is pressed, the parking brake solenoid valve is controlled to lose power, and if the pressure value of the parking brake pressure sensor is greater than a preset pressure value, or the parking switch is in an off state, the fault is diagnosed as abnormality / failure of the parking brake; In response to the parking release request signal, the parking brake solenoid valve is controlled to be energized to release the parking brake, and if the pressure value of the parking hydraulic accumulator pressure sensor is less than a preset pressure value, the fault is diagnosed as insufficient parking brake accumulator pressure; If the parking pressure switch is in the on state, or the pressure value of the parking brake pressure sensor is less than a preset pressure value, the diagnosis fault is that the parking brake is released abnormally.

[0014] Preferably, when a parking brake system fault is detected and diagnosed, the backup parking brake solenoid valve is controlled to be energized.

[0015] The present invention includes at least the following beneficial effects: (1) The introduction of a pressure feedback system and a fault detection and diagnosis module can monitor the pressure state of the brake system in real time, promptly discover and diagnose potential faults, form a real-time active safety monitoring mechanism, and better prevent safety accidents caused by brake system faults; (2) When the system detects a fault, the brake control system can automatically determine the fault location and cause, and provide maintenance personnel with accurate fault information, thereby greatly shortening the troubleshooting time. After the fault is eliminated, the re-power-on test ensures that the system can resume normal driving only when there is no fault, further improving the reliability and safety of the system; (3) The system adopts dual brake hydraulic control The braking circuit design includes an electric control circuit and a brake foot valve control circuit. The two are controlled independently of each other, ensuring that the vehicle can still perform effective braking when any control circuit fails, greatly improving driving safety; (4) Two independent angle sensors are set in the brake pedal. By collecting two brake voltage signals and comparing and verifying them, the problem of braking failure caused by a single sensor failure is effectively avoided, the reliability of braking control is enhanced, and more precise braking control is achieved through opening value conversion and selection; (5) When a parking brake failure is detected, the system can switch to the backup parking brake solenoid valve to ensure that the vehicle can still perform effective parking braking in an emergency, improving emergency response capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a safety brake control system for a mining dump truck based on brake feedback provided by the present invention; Figure 2 The present invention provides a schematic diagram of the connection relationship of components of a safety brake control system for a mining dump truck based on brake feedback.

[0017] Description of the drawings: front axle hydraulic accumulator 1, middle and rear axle hydraulic accumulator 2, front axle brake 3, middle and rear axle brake 4, parking hydraulic accumulator 5, parking brake solenoid valve 6, parking brake 7, parking pressure switch 8, pressure sensor 9, service brake solenoid valve 10, backup parking brake solenoid valve 11, first angle sensor 12, second angle sensor 13, emergency brake solenoid valve 14, relay valve 15. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0019] like Figure 1-2 As shown, the present invention provides a safety braking control system for a mining dump truck based on braking feedback, which includes: The service brake system includes a front axle hydraulic accumulator 1, a middle and rear axle hydraulic accumulator 2, a service brake solenoid valve 10, an emergency brake solenoid valve 14, a front axle relay valve 15, a middle and rear axle relay valve 15, a front axle brake 3 and a middle and rear axle brake 4, which are used to control the vehicle during driving; the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 are respectively installed at the front axle and the middle and rear axle positions of the vehicle frame, and are used to store the hydraulic energy required for braking. The driver can control the relay valve 15 in the brake system by stepping on the brake pedal to complete the service brake, and the angle sensor signal equipped with the brake pedal can also be used by the vehicle control unit to control the service brake solenoid valve 10. According to the angle and stepping speed of the brake pedal, the brake pressure of the front axle brake 3 and the middle and rear axle brake 4 is controlled. The front axle brake 3 and the middle and rear axle brake 4 convert the hydraulic pressure into the driving braking force to control the vehicle.

[0020] The parking brake system includes a parking hydraulic accumulator 5, a parking brake solenoid valve 6, a backup parking brake solenoid valve 11 and a parking brake 7, which are used to perform brake control when the vehicle is parked; the parking hydraulic accumulator 5 is used to store the hydraulic energy required for parking braking, the parking brake solenoid valve 6 controls the braking and release of the parking brake 7, the parking brake 7 provides braking force when the vehicle is parked to ensure that the vehicle will not move due to external force, and the backup parking brake solenoid valve 11 is controlled when the parking brake solenoid valve 6 fails.

[0021] The pressure feedback system includes a pressure switch and a pressure sensor 9. The pressure switch is arranged on the output circuit of the backup parking brake solenoid valve 11; the multiple pressure sensors 9 are respectively arranged on the output circuit of the front axle hydraulic accumulator 1, the output circuit of the middle and rear axle hydraulic accumulator 2, the output circuit of the parking hydraulic accumulator 5, the output circuit of the service brake solenoid valve 10, the input circuit of the front axle brake 3, the input circuit of the middle and rear axle brake 4, and the input circuit of the parking brake 7; the parking pressure switch 8 is located in the parking brake circuit. When the parking switch is pressed, the parking brake solenoid valve 6 loses power so that the hydraulic pressure of the parking brake circuit is less than the threshold of the parking pressure switch 8, the pressure switch 8 is turned on, and the corresponding connected instrument parking light is on, and the driver obtains the parking status of the vehicle. Pressure sensors 9 are respectively arranged on the output circuit of the front axle hydraulic accumulator 1, the output circuit of the middle and rear axle hydraulic accumulator 2, the output circuit of the parking hydraulic accumulator 5, the output circuit of the service brake solenoid valve 10, the input circuit of the front axle brake 3, the input circuit of the middle and rear axle brake 4, and the input circuit of the parking brake 7, and are used to monitor the pressure values ​​of the hydraulic pipeline and the brake pipeline in real time to ensure that the braking system can monitor the working status of each component in real time for fault detection and diagnosis.

[0022] The fault detection and diagnosis module is configured to determine that it is a brake system fault when the vehicle control unit detects that the pressure switch signal and the pressure value fed back by the pressure sensor 9 are abnormal, and to determine the cause of the fault.

[0023] As the core of the control system, the fault detection and diagnosis module is mainly composed of the vehicle control unit and the fault diagnosis algorithm therein. The vehicle control unit is responsible for receiving the signals from the pressure switch 8 and the pressure sensor 9, monitoring the status of the braking system in real time and running the fault diagnosis algorithm for fault detection and analysis. When the vehicle control unit detects that the pressure feedback of the pressure switch 8 is abnormal or the pressure value of any pressure sensor 9 is abnormal, it will be fed back to the vehicle control unit for judgment. When it is determined to be a brake system fault, the vehicle is immediately controlled to stop. Subsequently, the fault diagnosis is performed based on the pressure feedback and pressure value, the fault location and cause are confirmed, and the relevant personnel are notified to repair the fault. After the fault is eliminated and the power is turned on again, the fault detection is performed again. If the fault detection confirms that there is no brake fault, the vehicle is allowed to drive.

[0024] like Figure 1 As shown, an example of the actual design principle of a system is shown. The components in the safety brake control system of the mining dump truck are functionally modularized. The core module is the vehicle control unit VCU, and other components are connected to and controlled by the VCU. Other components include the solenoid valve configured in the braking system, the brake pedal, the key switch for starting the vehicle, the brake switch for service braking, the parking switch for parking, and the pressure sensor 9 and pressure switch 8 added in this application. The signals received and processed by the VCU include brake request signals and emergency motor work requests.

[0025] like Figure 2 As shown, a feasible example of the arrangement and connection relationship of the internal components of the braking system is shown. The front axle hydraulic accumulator 1, the middle and rear axle hydraulic accumulator 2 and the parking hydraulic accumulator 5 are connected to a hydraulic pump driven by a brake motor. When the accumulator pressure reaches a set value, it stops working. The energy stored in the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 is used to provide working pressure to the front axle brake 3 and the middle and rear axle brake 4. The energy stored in the parking hydraulic accumulator 5 is used to provide working pressure to the parking brake 7. A service brake solenoid valve 10 and an emergency brake solenoid valve 14 are arranged on the service brake hydraulic circuit.

[0026] The mining dump truck safety brake control system introduces a high-coverage pressure feedback system and a detailed fault detection and diagnosis module. When the system detects a fault, it monitors the pressure status of the brake system in real time and automatically determines the fault location and cause, providing maintenance personnel with accurate fault information, thereby greatly shortening the troubleshooting time.

[0027] In another technical solution, the service brake system further comprises a brake pedal and a brake foot valve, and the service brake system performs service brake control via an electric control circuit and a foot valve control circuit that are independent of each other; When the electric control circuit receives the feedback signal of the angle sensor provided in the brake pedal or the external brake request signal through the vehicle control unit, it controls the service brake solenoid valve 10 or the emergency brake solenoid valve 14 to brake the vehicle; the foot valve control circuit controls the front axle relay valve 15 or the middle and rear axle relay valve 15 through the hydraulic response of the foot brake valve when the brake pedal is stepped on, so as to control the vehicle braking according to the strength and speed of the driver stepping on the brake pedal. When the driver steps on the brake pedal, on the one hand, the equipped electric control circuit controls the service brake solenoid valve 10, thereby controlling the front axle and middle and rear axle brake relay valves 15; on the other hand, the foot valve control circuit can directly control the front axle and middle and rear axle brake relay valves 15. The two circuits can work independently. When one circuit fails, the control system of the other circuit can ensure the normal operation of the brake system; when both circuits are working normally, the circuit with greater brake pressure is preferentially responded to ensure safety.

[0028] In another technical solution, the service brake system further includes a brake pedal; wherein the brake pedal is provided with a first angle sensor 12 and a second angle sensor 13, the first angle sensor 12 collects a brake pedal angle signal A1, and the second angle sensor 13 collects a brake pedal angle signal A2; A1 and A2 are used as input signals of an electric control circuit; as an example, the voltage value of the first angle sensor 12 is set to be twice the voltage value of the second angle sensor 13, and when the voltage value exceeds a normal range, it is determined to be a sensor failure; The voltage values ​​of the collected brake pedal angle signals A1 and A2 are respectively subjected to voltage range verification, including: if the voltage value of the collected angle signal is not within a preset normal voltage range, determining that the brake pedal has a signal over-limit fault; The brake pedal angle signal A1 and the brake pedal angle signal A2 that have passed the voltage range verification are converted into the corresponding brake pedal opening value. According to the electrical characteristics of the device, the A1 and A2 voltage values ​​that have passed the verification are converted into the corresponding brake pedal opening value through a two-dimensional table lookup, and the opening value is 0%-100% of the brake pedal travel.

[0029] If the voltage multiples of the brake pedal angle signal A1 and the brake pedal angle signal A2 are stable within a set range within a specified time, a larger opening value is output as the effective opening value of the brake pedal; If the voltage multiples of the brake pedal angle signal A1 and the brake pedal angle signal A2 exceed the set range within the specified time, a 100% maximum brake opening is output and a fault message is reported.

[0030] As an example, it is determined whether the multiples of the voltage values ​​of A1 and A2 are within the set multiples range, such as between 1.8 and 2.2 times. If so, it is determined that the two signals have passed the verification, and the corresponding larger opening value is output as the brake pedal input opening value; if the multiples deviate slightly from the set design, such as between 1.6 and 1.8 times, or between 2.2 and 2.4 times, the corresponding larger opening value is output as the brake pedal input opening value, and timing is performed. After exceeding the set time, such as 1s, it is considered that the angle sensor signal is unreliable, and 100% maximum brake opening is output, fault information is reported, and driving is prohibited; If the multiple deviation is too large and exceeds the set time, such as 0.5s, the angle sensor signal is considered unreliable, 100% maximum brake opening is output, fault information is reported and driving is prohibited.

[0031] In another technical solution, the fault detection and diagnosis mechanism includes a parking brake power-on detection mechanism, which operates as follows: In response to the vehicle start signal when the vehicle key switch is activated, if the vehicle control unit detects that the parking brake solenoid valve 6 is not in the parking state, the parking brake solenoid valve 6 is controlled to work, and the driver is prompted to press the parking switch. When it is detected that the driver performs parking and releasing operations, it is determined that the parking brake power-on detection has passed; in response to the vehicle start signal when the vehicle key switch is activated, if the vehicle control unit detects that the parking brake solenoid valve 6 is in the parking state, when the parking pressure switch 8 is disconnected or the pressure value of the parking brake 7 pressure sensor 9 is higher than the normal value of the parking state, it is determined that the parking brake power-on detection has not passed, the parking system is abnormal / failed, and fault information is reported.

[0032] This function is to perform parking detection when the vehicle is powered on. It mainly checks whether the vehicle is parked when the vehicle is started, and detects whether the parking brake system has any faults. If it is not parked, it will park the vehicle and prompt the driver to operate. Its operation mode is as follows: In response to the vehicle start signal when the vehicle key switch is activated, when the vehicle key signal changes from the OFF position to the ON position, it is detected that the parking brake solenoid valve 6 is in the parking state, the parking pressure switch 8 is turned on and the pressure value of the parking brake pressure sensor 9 is less than the normal value of the parking state, the vehicle power-on detection passes; When the vehicle key signal changes from OFF to ON, if it is detected that the parking brake solenoid valve 6 is in the parking state, but the parking pressure switch 8 is disconnected or the pressure value of the parking brake pressure sensor 9 is higher than the normal value of the parking state, the parking system is judged to be abnormal / failed, the fault information is reported and driving is prohibited, and the parking brake power-on test fails.

[0033] When it is detected that the parking brake solenoid valve 6 is not in the parking state, the vehicle control unit controls the parking brake solenoid valve 6 to work automatically, and prompts the driver to press the parking switch to release the safety lock mode. Driving is prohibited during this period. After the driver presses the parking switch to park and release the operation, the parking brake power-on detection passes.

[0034] In another technical solution, the service brake system further includes a brake motor, and the fault detection and diagnosis module includes an emergency brake power-on detection mechanism, which operates as follows: In response to the vehicle start signal when the vehicle key switch is activated, when the brake motor works for a set time, the emergency brake solenoid valve 14 is energized, and if a short circuit or an open circuit is detected, fault information is reported and driving is prohibited; In response to the vehicle start signal when the vehicle key switch is activated, when the brake motor works for a set time, the emergency brake solenoid valve 14 is energized, and if no fault is detected, the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 are detected; If the pressure value of at least one of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 does not reach the preset normal pressure value, the emergency brake fault type and position are analyzed according to the position of the pressure sensor 9 that does not reach the normal pressure value; otherwise, It is determined that the emergency brake power-on test has passed.

[0035] The emergency brake solenoid valve 14 can control the front axle brake 3 and the middle and rear axle brakes 4. In an emergency, the emergency brake solenoid valve 14 is controlled by the vehicle control unit to achieve emergency braking. Each time the vehicle is powered on, an emergency brake power-on test is performed, so that the emergency brake solenoid valve 14 is powered on for 1 second, and the test is performed without stepping on the brake pedal. Its operation mode is: The vehicle key signal changes from OFF to ON, and the brake motor works for a certain period of time, and the emergency brake solenoid valve 14 is energized. If there is a short circuit or an open circuit, the fault information is reported and driving is prohibited; if there is no short circuit or open circuit fault, the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 are detected. When the pressure value is greater than a certain pressure value, the emergency brake power-on test is passed, and the emergency brake power-on test is output to allow gear shifting, vehicle operation, and release of the parking brake.

[0036] If the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 have no faults, but the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 do not reach the preset normal pressure values, the fault diagnosis information is output as the emergency brake power-on detection failure fault, and a second emergency brake power-on detection is performed after a preset time interval. The following fault diagnosis is performed according to the pressure value of the pressure sensor 9 during the second power-on detection: If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 both reach the preset normal pressure values, it is determined that the emergency brake power-on detection has passed, and a brake system slow charging fault is output; If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake 4 pressure sensor 9 do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 pressure sensor 9 reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake execution system fault is output; If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 4 do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 pressure sensors 9 do not reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake system filling fault is output; If the pressure value of only one of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 reaches the preset normal pressure value, it is determined that the emergency brake power-on detection has failed, and a brake system fault is output.

[0037] Considering the time required for the air pressure to rise from zero to the air pressure required for emergency braking when the vehicle is started and the time required for the air pressure sensor to feedback, the time interval between the first emergency braking power-on detection and the second emergency braking power-on detection is set. The time interval can be flexibly adjusted, such as setting it to 10s. The second emergency braking power-on detection can further verify whether the cause of the fault is insufficient power of the brake motor or leakage of the hydraulic system. The following fault diagnosis is performed based on the pressure value of pressure sensor 9 during the second power-on detection: If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 both reach the preset normal pressure values, the output is "brake system slow charging fault", the possible reasons are: insufficient brake motor power, incorrect calibration of the detection time interval or pressure value, and leakage of the brake system hydraulic circuit; If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator pressure sensor 9 and the middle and rear axle hydraulic accumulator 2 pressure sensor 9 are normal, the output brake execution system failure may be caused by: leakage of the front axle and middle and rear axle brake execution hydraulic circuit, failure of the front axle and middle and rear axle brake relay valve, etc.; If the pressure values ​​of the two pressure sensors 9 do not reach the preset normal pressure value, and the pressure values ​​of the pressure sensors 9 of the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 are abnormal, it is determined that the emergency brake power-on detection has not passed, and a brake system filling fault is output. Possible causes: brake hydraulic circuit leakage fault, brake motor fault, brake accumulator fault, etc. If only one of the pressure sensors 9 reaches the preset normal pressure value, and the pressure values ​​of the pressure sensors 9 of the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 are normal, it is determined that the emergency brake power-on detection has not passed, and the brake system slow charging fault, front axle brake hydraulic circuit fault or middle and rear axle brake hydraulic circuit fault are output. Possible reasons include: leakage of the front axle or middle and rear axle brake execution hydraulic circuit, failure of the front axle or middle and rear axle brake relay valve, etc.

[0038] If the pressure value of only one of the pressure sensors 9 reaches the preset normal pressure value, and the pressure value of the circuit accumulator pressure sensor 9 corresponding to the abnormal pressure sensor 9 is abnormal, it is determined that the emergency brake power-on detection has not passed, and a front axle or middle and rear axle brake system fault is output. Possible reasons include: leakage of the front axle or middle and rear axle brake hydraulic circuit, failure of the front axle or middle and rear axle brake accumulator, etc.

[0039] If the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 have no faults, but the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 do not reach the preset normal pressure values, the fault diagnosis information is output as the emergency brake power-on detection failure fault, and a second emergency brake power-on detection is performed after a preset time interval. The following fault diagnosis is performed according to the pressure value of the pressure sensor 9 during the second power-on detection: If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 both reach the preset normal pressure values, it is determined that the emergency brake power-on detection has passed, and a brake system slow charging fault is output; If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake 4 pressure sensor 9 do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 pressure sensor 9 reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake execution system fault is output; If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 4 do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator 1 and the middle and rear axle hydraulic accumulator 2 pressure sensors 9 do not reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake system filling fault is output; If the pressure value of only one of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 reaches the preset normal pressure value, it is determined that the emergency brake power-on detection has failed, and a brake system fault is output.

[0040] When the emergency brake power-on detection fails, the emergency brake solenoid valve 14 and the service brake solenoid valve 10 are prohibited from working to prevent the hydraulic system from spraying liquid; The fault detection and diagnosis mechanism includes an emergency braking mechanism: In response to the emergency brake request signal when the emergency brake switch is pressed, the emergency brake solenoid valve 14 is controlled to be energized, and the parking brake solenoid valve 6 is de-energized. If during this period, the pressure values ​​of the mid-rear axle brake hydraulic circuit pressure sensor 9 and the front axle brake hydraulic circuit pressure sensor 9 are detected to be less than or equal to a certain pressure value, the fault is diagnosed as a brake system abnormality / failure, and the service brake solenoid valve 10 is controlled to be energized; In response to the emergency brake request signal when the emergency brake switch is pressed and disconnected, the vehicle control unit detects that the parking brake solenoid valve 6 is in the parking state, the parking pressure switch 8 is turned on and the pressure value of the parking brake pressure sensor 9 is less than the normal value of the parking state, then the emergency brake is allowed to be exited and the emergency brake solenoid valve 14 is controlled to lose power; if the current vehicle is in an unparked state, the driver is prompted to "press the parking brake to exit the safety lock"; if there is a parking system fault such as parking brake abnormality / failure, it is prohibited to release the emergency brake.

[0041] The system also includes an emergency brake switch and a parking switch. The process of determining the cause of the fault includes: In response to the emergency brake request signal when the emergency brake switch is pressed, the emergency brake solenoid valve 14 is controlled to be energized and the parking brake solenoid valve 6 is de-energized. If the pressure values ​​of the front axle brake pressure sensor 9 and the middle and rear axle brake pressure sensor 9 do not reach the preset pressure values, the fault is diagnosed as a brake system abnormality / failure, and the service brake solenoid valve 10 is controlled to be energized; In response to the parking request signal when the parking switch is pressed, the parking brake solenoid valve 6 is controlled to lose power. If the pressure value of the parking brake 7 pressure sensor 9 is greater than the preset pressure value, or the parking switch is not in the on state, the fault is diagnosed as abnormality / failure of the parking brake; In response to the parking release request signal, the parking brake solenoid valve 6 is controlled to be energized to release the parking brake. If the pressure value of the parking hydraulic accumulator 5 pressure sensor 9 is less than the preset pressure value, the fault is diagnosed as insufficient parking brake accumulator pressure. If the parking pressure switch 8 is in the on state, or the pressure value of the parking brake 7 pressure sensor 9 is less than the preset pressure value, the fault is diagnosed as abnormal release of the parking brake 7. The fault detection and diagnosis mechanism includes the parking brake mechanism: In response to the parking request signal when the parking brake switch is pressed, the parking brake solenoid valve 6 is controlled to lose power, and the vehicle is parked. At the same time, the parking brake circuit pressure switch 8 is in the on state after the parking brake solenoid valve 6 loses power, and the parking switch indicator light is on. If the pressure of the parking brake circuit pressure sensor 9 is greater than a certain pressure value, or the pressure switch 1 is not in the on state, the fault diagnosis is "parking brake abnormality / failure", and driving is not allowed.

[0042] In response to the parking release request signal when the parking brake switch is turned off, it is detected whether the brake pedal is stepped on. When the brake pedal is not stepped on, the driver is prompted to "step on the brake pedal to release the parking"; when the brake pedal is stepped on, the parking brake solenoid valve 6 is controlled to be energized, the vehicle parking brake is released, the parking pressure switch 8 is turned off, and the instrument parking light is turned off. If the pressure of the parking hydraulic accumulator 5 pressure sensor 9 is less than a certain pressure value during this period, the fault "insufficient pressure of the parking brake hydraulic accumulator" is output; if the parking pressure switch 8 is in the on state, or the pressure value of the parking brake pressure sensor 9 is less than the preset pressure value, the fault "abnormal release of the parking brake" is output.

[0043] When the parking brake system fault is detected and diagnosed, the standby parking brake solenoid valve 11 is controlled to be energized. When the vehicle needs to release the parking brake, the parking brake solenoid valve 6 is controlled to lose power, but when the parking pressure switch 8 is in the disconnected state or the pressure of the parking pressure sensor 9 is greater than the preset pressure, the fault diagnosis is "parking brake system fault", and the standby parking brake solenoid valve 11 is controlled to be energized to perform a parking release. After parking is performed again during this power-on process, parking release is prohibited.

[0044] It should be noted that, although the above describes the various steps in a specific order, it does not mean that the various steps must be performed in the above specific order. In fact, some of these steps can be performed concurrently or even in a different order, as long as the required functions can be achieved. The number of devices and processing scales described here are used to simplify the description of the present invention, and the application, modification and variation of the present invention are obvious to those skilled in the art.

[0045] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A safety braking control system for a mining dump truck based on braking feedback, characterized in that: include: The service brake system includes a front axle hydraulic accumulator, a middle and rear axle hydraulic accumulator, a service brake solenoid valve, an emergency brake solenoid valve, a front axle relay valve, a middle and rear axle relay valve, a front axle brake and a middle and rear axle brake, and is used to control the braking of the vehicle during driving; A parking brake system, including a parking hydraulic accumulator, a parking brake solenoid valve, a backup parking brake solenoid valve and a parking brake, for performing brake control when the vehicle is parked; A pressure feedback system, comprising a pressure switch and a pressure sensor, wherein the pressure switch is arranged on the output circuit of the backup parking brake solenoid valve; a plurality of the pressure sensors are respectively arranged on the output circuit of the front axle hydraulic accumulator, the output circuit of the middle and rear axle hydraulic accumulator, the output circuit of the parking hydraulic accumulator, the output circuit of the service brake solenoid valve, the input circuit of the front axle brake, the input circuit of the middle and rear axle brake, and the input circuit of the parking brake; The fault detection and diagnosis module is configured to determine that it is a brake system fault when the vehicle control unit detects that the pressure switch signal and the pressure sensor feedback pressure value are abnormal, and determine the cause of the fault.

2. The safety braking control system for a mining dump truck based on braking feedback according to claim 1 is characterized in that: The service brake system further comprises a brake pedal and a brake foot valve, and the service brake system performs service brake control via an electric control circuit and a foot valve control circuit which are independent of each other; When the electric control circuit receives a feedback signal from an angle sensor disposed in the brake pedal or an external brake request signal through the vehicle control unit, the electric control circuit controls the service brake solenoid valve or the emergency brake solenoid valve to brake the vehicle; The foot valve control circuit controls the front axle relay valve or the middle and rear axle relay valve through the hydraulic response of the foot brake valve when the brake pedal is depressed, so as to control vehicle braking according to the force and speed at which the driver depresses the brake pedal.

3. The safety braking control system for a mining dump truck based on braking feedback according to claim 1 is characterized in that: The service brake system also includes a brake pedal; wherein, The brake pedal is provided with a first angle sensor and a second angle sensor, the first angle sensor collects a brake pedal angle signal A1, and the second angle sensor collects a brake pedal angle signal A2; The voltage values ​​of the collected brake pedal angle signals A1 and A2 are respectively subjected to voltage range verification, including: if the voltage value of the collected angle signal is not within a preset normal voltage range, determining that the brake pedal has a signal over-limit fault; Analyze and convert the brake pedal angle signal A1 and the brake pedal angle signal A2 that pass the voltage range check into the corresponding brake pedal opening value; If the voltage multiples of the brake pedal angle signal A1 and the brake pedal angle signal A2 are stable within a set range within a specified time, a larger opening value is output as the effective opening value of the brake pedal; If the voltage multiples of the brake pedal angle signal A1 and the brake pedal angle signal A2 exceed the set range within a specified time, a 100% maximum brake opening is output and a fault message is reported.

4. The safety braking control system for a mining dump truck based on braking feedback according to claim 1 is characterized in that: The fault detection and diagnosis mechanism includes a parking brake power-on detection mechanism, which operates as follows: In response to a vehicle start signal when a key switch of the vehicle is activated, if the vehicle control unit detects that the parking brake solenoid valve is not in a parking state, the parking brake solenoid valve is controlled to operate, and the driver is prompted to press the parking switch. When it is detected that the driver performs parking and releasing operations, it is determined that the parking brake power-on detection has passed; In response to a vehicle start signal when the vehicle key switch is activated, if the vehicle control unit detects that the parking brake solenoid valve is in the parking state, when the parking pressure switch is disconnected or the pressure value of the parking brake pressure sensor is higher than the normal value of the parking state, it is determined that the parking brake power-on detection has failed, the parking system is abnormal / failed, and fault information is reported.

5. The safety braking control system for a mining dump truck based on braking feedback according to claim 1 is characterized in that: The service brake system also includes a brake motor, and the fault detection and diagnosis module includes an emergency brake power-on detection mechanism, which operates as follows: In response to a vehicle start signal when the vehicle key switch is activated, when the brake motor works for a set time, the emergency brake solenoid valve is energized, and if a short circuit or an open circuit is detected, fault information is reported and driving is prohibited; In response to a vehicle start signal when a key switch of the vehicle is activated, when the brake motor works for a set time, the emergency brake solenoid valve is energized, and no fault is detected, then the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensors are detected; If the pressure value of at least one of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor does not reach the preset normal pressure value, the emergency brake fault type and position are analyzed according to the position of the pressure sensor that does not reach the normal pressure value; otherwise, It is determined that the emergency brake power-on test has passed.

6. The safety braking control system for a mining dump truck based on braking feedback according to claim 5 is characterized in that: If the front axle brake pressure sensor and the middle and rear axle brake pressure sensor have no faults, but the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor do not reach the preset normal pressure values, the fault diagnosis information is output as an emergency brake power-on detection failure fault, and a second emergency brake power-on detection is performed after a preset time interval. The following fault diagnosis is performed according to the pressure values ​​of the pressure sensors during the second power-on detection: If the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor both reach the preset normal pressure values, it is determined that the emergency brake power-on detection has passed, and a brake system slow charging fault is output; If the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator and the middle and rear axle hydraulic accumulator pressure sensors reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake execution system fault is output; If the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor do not reach the preset normal pressure value, and the pressure values ​​of the front axle hydraulic accumulator and the middle and rear axle hydraulic accumulator pressure sensors do not reach the preset normal pressure value, it is determined that the emergency brake power-on detection has not passed, and a brake system filling fault is output; If the pressure value of only one of the front axle brake pressure sensor and the mid-rear axle brake pressure sensor reaches the preset normal pressure value, it is determined that the emergency brake power-on detection has failed, and a brake system fault is output.

7. The safety braking control system for a mining dump truck based on braking feedback according to claim 5 is characterized in that: If the front axle brake pressure sensor and the middle and rear axle brake pressure sensor have no faults, when the pressure value of one of the pressure sensors does not reach the preset normal pressure value, an emergency brake power-on detection failure fault is output, and a second emergency brake power-on detection is performed after a preset time interval. The following fault diagnosis is performed according to the pressure value of the pressure sensor during the second detection: If the pressure value of one of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor reaches the preset normal pressure value in the second detection, and the pressure value of the corresponding circuit accumulator pressure sensor is normal, it is determined that the emergency brake power-on detection has not passed, and according to the position of one of the pressure sensors, fault diagnosis information is output: front axle brake pressure fault or middle and rear axle brake pressure fault; If the pressure value of one of the front axle brake pressure sensor and the middle and rear axle brake pressure sensor does not reach the preset normal pressure value in the second detection, and the pressure value of the corresponding circuit accumulator pressure sensor is normal, it is determined that the emergency brake power-on detection has not passed, and according to the position of the pressure sensor that has not passed the power-on detection, fault diagnosis information is output: front axle brake system failure or middle and rear axle brake system failure; If the pressure value of one of the front axle brake pressure sensors and the mid-rear axle brake pressure sensors does not reach the preset normal pressure value in the second detection, and the pressure value of the pressure sensor of the corresponding circuit accumulator does not reach the preset normal pressure value, it is determined that the emergency brake power-on detection has failed, and based on the position of the pressure sensor that has failed the power-on detection, fault diagnosis information is output: front axle brake system failure or mid-rear axle brake system failure.

8. The safety braking control system for a mining dump truck based on braking feedback according to claim 1 is characterized in that: It also includes the emergency brake switch and the parking switch. The process of determining the cause of the fault includes: In response to an emergency brake request signal when the emergency brake switch is pressed, the emergency brake solenoid valve is controlled to be energized and the parking brake solenoid valve is de-energized; if the pressure values ​​of the front axle brake pressure sensor and the middle and rear axle brake pressure sensors do not reach a preset pressure value, the fault is diagnosed as a brake system abnormality / failure, and the service brake solenoid valve is controlled to be energized; In response to a parking request signal when the parking switch is pressed, the parking brake solenoid valve is controlled to lose power, and if the pressure value of the parking brake pressure sensor is greater than a preset pressure value, or the parking switch is in an off state, the fault is diagnosed as abnormality / failure of the parking brake; In response to the parking release request signal, the parking brake solenoid valve is controlled to be energized to release the parking brake, and if the pressure value of the parking hydraulic accumulator pressure sensor is less than a preset pressure value, the fault is diagnosed as insufficient parking brake accumulator pressure; If the parking pressure switch is in the on state, or the pressure value of the parking brake pressure sensor is less than a preset pressure value, the diagnosis fault is that the parking brake is released abnormally.

9. The safety braking control system for a mining dump truck based on braking feedback according to claim 8, characterized in that: When a parking brake system fault is detected and diagnosed, the backup parking brake solenoid valve is controlled to be energized.

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