A redundant steering system and unmanned mining truck

Abstract

The present invention relates to a redundant steering system and an unmanned mining truck, which belongs to the field of steering systems and solves the problem that the redundant steering system does not achieve complete redundancy. It includes a host computer, a chassis domain controller, a redundant electric steering gear, a redundant full hydraulic steering gear, a steering front axle, a pressure sensor, a left turn angle sensor and a right turn angle sensor; the host computer sends a steering control instruction to the chassis domain controller, the chassis domain controller sends the steering control instruction to the redundant electric steering gear according to the current actual state of the whole vehicle and controls the redundant full hydraulic steering gear to work at the same time, the redundant electric steering gear drives the full hydraulic steering gear to drive the wheels to rotate, and the pressure sensor, the left turn angle sensor and the right turn angle sensor simultaneously feed back the current steering pressure and the actual wheel angle to the chassis domain controller. Through the redundant design of the whole system, the steering system can meet the requirements of automatic driving under any circumstances, and improves the stability and reliability of automatic driving of mining trucks.

Description

Technical Field

[0001] The invention belongs to the field of steering systems, and in particular relates to a redundant steering system and an unmanned mining truck. Background Art

[0002] Due to the heavy load of the mine truck, there is no electric steering gear on the market that can directly drive the wheels to rotate. The current solution is to install the electric steering gear on the upper level of the full hydraulic steering gear. This solution is also based on this structure. At present, the redundant steering in the unmanned mine truck mostly uses two steering systems to achieve wire-controlled steering, which has a complex structure, is difficult to install and maintain, and is difficult to control. At present, the redundant steering system in the unmanned mine truck has not achieved complete redundancy, and most of them only have electric steering gear redundancy. That is, the current redundant steering system has a complex structure, is difficult to install and maintain, and has a high failure rate; the current redundant steering system is complex to control, which increases the difficulty of use; and true full system redundancy has not been achieved. Therefore, it is necessary to provide a redundant steering system and an unmanned mine truck to solve the above problems. Summary of the invention

[0003] In view of the above deficiencies in the prior art, the purpose of the invention is to provide a redundant steering system and an unmanned mining truck, which solve the problem that the redundant steering system does not achieve complete redundancy and the steering system has a complex structure.

[0004] The present invention proposes a redundant steering system, which comprises a host computer, a chassis domain controller, a redundant electric steering gear, a redundant full hydraulic steering gear, a steering front axle, a pressure sensor, a left turn angle sensor and a right turn angle sensor. When working, the host computer sends a steering control instruction to the chassis domain controller, and the chassis domain controller sends the steering control instruction to the redundant electric steering gear according to the current actual state of the whole vehicle and controls the redundant full hydraulic steering gear to work at the same time. The redundant electric steering gear drives the full hydraulic steering gear to drive the wheels to rotate, and the pressure sensor, the left turn angle sensor and the right turn angle sensor simultaneously feed back the current steering pressure and the actual wheel angle to the chassis domain controller. When the actual wheel angle reaches the target wheel angle, the redundant electric steering gear stops outputting. The redundant electric steering gear includes two electric steering gears, and the redundant full hydraulic steering gear includes two full hydraulic steering gears. When it is determined that the steering system fails, another electric steering gear or full hydraulic steering gear is used to work.

[0005] Furthermore, the redundant electric steering gear and the redundant full hydraulic steering gear are mechanically connected, the redundant full hydraulic steering gear and the steering front axle are mechanically connected, the pressure sensor is installed in the hydraulic circuit between the redundant full hydraulic steering gear and the steering front axle, and the steering front axle directly drives the wheels to rotate; the host computer is an unmanned driving controller, and the host computer, chassis domain controller, redundant electric steering gear, pressure sensor and left turn angle sensor and right turn angle sensor are electrically connected.

[0006] Furthermore, the redundant electric steering gear has power supply redundancy, CAN bus redundancy, steering angle sensor redundancy and electric steering gear redundancy; when driving manually, the redundant electric steering gear performs power steering; when driving automatically, the redundant electric steering gear performs wire-controlled steering and responds to the steering control instructions of the automatic driving.

[0007] Furthermore, the redundant electric steering gear includes two motor controllers and two motors, forming two sets of electric steering gears; the redundant electric steering gear has two independent power supplies, which are independent of each other and are respectively connected to the two sets of electric steering gears in the redundant electric steering gear.

[0008] Furthermore, the redundant electric steering gear has two independent CAN buses, which are independent of each other and respectively connected to the two sets of electric steering gears in the redundant electric steering gear; the redundant electric steering gear has two independent steering angle sensors, which are respectively connected to the chassis domain controller, and the chassis domain controller sends the detected actual steering angle of the wheel to the redundant electric steering gear.

[0009] Furthermore, the redundant full-hydraulic steering gear is composed of two sets of full-hydraulic steering gears, solenoid valves and piping parts, wherein the solenoid valve is controlled by the chassis domain controller and is used to switch the two sets of full-hydraulic steering gears to work; under normal working conditions, one of the full-hydraulic steering gears works; when the chassis domain controller detects a steering abnormality, the solenoid valve is energized, and the solenoid valve is switched to make the other full-hydraulic steering gear work to ensure normal steering.

[0010] Furthermore, the step of determining a steering system failure specifically includes: determining whether the steering system is abnormal through a target wheel angle sent by a host computer and an actual wheel angle detected by a current angle sensor, based on θ=θ0+wt, t=t1-t2, Δθ=θ1-θ, wherein θ is the target wheel angle; θ0 is the initial actual wheel angle when a steering control command is issued; θ1 is the actual wheel angle when the steering control command ends; Δθ is the difference between the actual wheel angle and the target wheel angle when control ends; w is the angular velocity when the wheel is turning; t is the effective steering time when the wheel is turning; t1 is the actual consumed time of a command control cycle; t2 is the invalid time of a command control cycle; w is calculated through the motor speed feedback from the redundant electric steering gear; θ0 and θ1 are detected in real time by the angle sensor; when Δθ exceeds a set threshold, there is a risk of failure in the steering system.

[0011] Furthermore, the step of determining a steering system fault also includes:

[0012] By detecting the steering system pressure, it is determined whether the system is faulty, and the M value is determined based on the ΔP=P1-P0 and Δθ1=θ-θ0 curves. M is the deviation value between the actually detected ΔP' and Δθ1' values ​​and the ΔP=P1-P0 and Δθ1=θ-θ0 curves. When M reaches a threshold value, there is a risk of failure in the steering system.

[0013] Performing weighted calculation based on Δθ and M to determine whether the steering system is faulty, including: based on q=αΔθ+βM, when q is greater than a set threshold, determining that the steering system is faulty;

[0014] Among them, P0 is the initial actual steering pressure of the wheel when the control command is issued; P1 is the actual wheel steering pressure when the command ends; ΔP is the difference in actual wheel steering pressure at the end of control; Δθ1 is the difference between the target wheel angle and the initial wheel angle when the control command is issued; q is the probability of steering system failure, α is the Δθ weighting coefficient, and β is the M weighting coefficient.

[0015] Furthermore, the two sets of electric steering gears are respectively the first electric steering gear and the second electric steering gear, and the two full hydraulic steering gears are respectively the first full hydraulic steering gear and the second full hydraulic steering gear; when the steering system fails and the first electric steering gear or the second electric steering gear works normally, it is determined that the first full hydraulic steering gear is faulty, and the chassis domain controller switches to the second full hydraulic steering gear; when the steering system fails and the first electric steering gear fails, the chassis domain controller controls the second electric steering gear to work; when the steering system fails and the redundant electric steering gear works normally, it is possible that the first full hydraulic steering gear is faulty. After the chassis domain controller switches to the second full hydraulic steering gear, it is still determined that the steering system is faulty, then the redundant electric steering gear is faulty.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. Through the redundant design of the entire system, the steering system can meet the requirements of autonomous driving under any circumstances, improving the stability and reliability of autonomous driving of mining trucks.

[0018] 2. The system is simple, easy to control, simple on-site installation and after-sales, shortened debugging cycle, reduced personnel costs, and reduced human errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are only used to illustrate specific embodiments and are not considered to limit the present invention. In the entire drawings, the same reference symbols represent the same components. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0020] Figure 1A structural schematic diagram of a redundant steering system in an embodiment of the present invention;

[0021] Figure 2 A flowchart of a redundant steering system in an embodiment of the present invention;

[0022] Figure 3 The figure is a schematic diagram of the installation and connection of a redundant steering system in an embodiment of the present invention.

[0023] Figure numerals: 1 - redundant electric steering gear, 2 - redundant full hydraulic steering gear, 3 - pressure sensor, 4 - left turning angle sensor, 5 - right turning angle sensor, 6 - steering wheel, 7 - steering front axle. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present invention.

[0025] Furthermore, in the following description, descriptions of well-known technologies are omitted to avoid unnecessarily obscuring the concepts disclosed in the present invention.

[0026] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of methods and systems consistent with some aspects of the present invention as detailed in the appended claims.

[0027] System Example

[0028] like Figure 1 , Figure 2 and Figure 3As shown, the present invention provides a redundant steering system, which includes a host computer, a chassis domain controller, a redundant electric steering gear 1, a redundant full hydraulic steering gear 2, a steering front axle 7, a pressure sensor 3, a left turn angle sensor 4, and a right turn angle sensor 5. The redundant electric steering gear 1 and the redundant full hydraulic steering gear 2 are mechanically connected, the redundant full hydraulic steering gear 2 and the steering front axle 7 are mechanically connected, the pressure sensor 3 is installed in the hydraulic circuit between the redundant full hydraulic steering gear 2 and the steering front axle 7, and the steering front axle 7 directly drives the wheels to rotate; the host computer is an unmanned driving controller, and the host computer, the chassis domain controller, the redundant electric steering gear 1, the pressure sensor 3, the left turn angle sensor 4, and the right turn angle sensor 5 are electrically connected. When working, the host computer sends the steering control instruction to the chassis domain controller. The chassis domain controller sends the steering control instruction to the redundant electric steering gear 1 and controls the redundant full hydraulic steering gear 2 to work according to the current actual state of the vehicle. The redundant electric steering gear 1 drives the full hydraulic steering gear to drive the wheel to rotate. The pressure sensor 3, the left turning angle sensor 4 and the right turning angle sensor 5 simultaneously feed back the current steering pressure and the actual wheel angle to the chassis domain controller; when the actual wheel angle reaches the target wheel angle, the redundant electric steering gear 1 stops outputting, and the full hydraulic steering gear also loses driving force at this time, and the wheel rotation stops immediately; the redundant electric steering gear 1 includes two electric steering gears, and the redundant full hydraulic steering gear 2 includes two full hydraulic steering gears. When it is determined that the steering system fails, another electric steering gear or full hydraulic steering gear is used to work. Since each part of the entire system has redundant backup, when a steering abnormality occurs during the automatic driving process, the backup system can be used to continue to respond to the automatic driving needs, and maintenance can be carried out when the production is finished.

[0029] In the embodiment of the present invention, the two electric steering gears are respectively the first electric steering gear (motor 1) and the second electric steering gear (motor 2), and the two full hydraulic steering gears are respectively the first full hydraulic steering gear (steering gear 1) and the second full hydraulic steering gear (steering gear 2); when the steering system fails and the first electric steering gear or the second electric steering gear works normally, it is determined that the first full hydraulic steering gear fails, and the chassis domain controller switches to the second full hydraulic steering gear; when the steering system fails and the first electric steering gear fails, the chassis domain controller controls the second electric steering gear to work; when the steering system fails and the redundant electric steering gear 1 works normally, it is possible that the first full hydraulic steering gear fails. After the chassis domain controller switches to the second full hydraulic steering gear, it is still determined that the steering system fails, and the redundant electric steering gear 1 fails. Fault judgment of redundant electric steering gear 1: Under normal circumstances, since the redundant electric steering gear 1 itself has a control chip, the redundant electric steering gear 1 can autonomously feedback the fault status in most cases; when the redundant electric steering gear 1 cannot feedback, the chassis domain controller can judge whether the redundant electric steering gear 1 is faulty through the CAN bus status or through the following method.

[0030] In the embodiment of the present invention, the redundant electric steering gear 1 has power supply redundancy, CAN bus redundancy, angle sensor redundancy and electric steering gear redundancy; when manually driving, the redundant electric steering gear 1 performs power steering; when automatically driving, the redundant electric steering gear 1 performs wire control steering, responding to the steering control command of the automatic driving. The redundant electric steering gear 1 contains two motor controllers and two motors, forming two sets of electric steering gears; the redundant electric steering gear 1 has two independent power supplies, the two power supplies are independent of each other and are respectively connected to the two sets of electric steering gears in the redundant electric steering gear 1. The redundant electric steering gear 1 has two independent CAN buses, the two CAN buses are independent of each other and are respectively connected to the two sets of electric steering gears in the redundant electric steering gear 1; the redundant electric steering gear 1 has two independent angle sensors, the two angle sensors are respectively connected to the chassis domain controller, and the chassis domain controller sends the detected actual wheel angle to the redundant electric steering gear 1.

[0031] In an embodiment of the present invention, the redundant full-hydraulic steering gear 2 is composed of two sets of full-hydraulic steering gears, solenoid valves and pipeline parts, wherein the solenoid valve is controlled by the chassis domain controller and is used to switch the two sets of full-hydraulic steering gears to work; under normal working conditions, one of the full-hydraulic steering gears (steering gear 1) works; when the chassis domain controller detects a steering abnormality, the solenoid valve is energized, and the solenoid valve is switched to make the other full-hydraulic steering gear (steering gear 2) work to ensure normal steering.

[0032] In the embodiment of the present invention, when the chassis domain controller receives the steering control instruction from the host computer, the chassis domain controller sends the target steering angle and the current steering angle to the redundant electric steering gear 1, and controls the redundant electric steering gear 1 to start working. In the absence of faults, the two electric steering gears in the redundant electric steering gear 1 system are driven simultaneously to increase the steering reliability. When one electric steering gear fails, the other electric steering gear works alone. When the chassis domain controller receives the steering control instruction from the host computer, while controlling the redundant electric steering gear 1 to start working, it also controls the steering gear 1 in the redundant full hydraulic steering gear 2 to work. If the steering gear 1 fails, the steering gear 2 is controlled to work.

[0033] In an embodiment of the present invention, the step of determining a steering system fault specifically includes: determining whether the steering system is abnormal through the target wheel angle sent by the host computer and the actual wheel angle detected by the current angle sensor, based on θ=θ0+wt, t=t1-t2, Δθ=θ1-θ, wherein θ is the target wheel angle; θ0 is the initial actual wheel angle when the steering control command is issued; θ1 is the actual wheel angle when the steering control command ends; Δθ is the difference between the actual wheel angle and the target wheel angle when the control ends; w is the angular velocity when the wheel is turned; t is the effective steering time when the wheel is turned; t1 is the actual consumed time of a command control cycle; t2 is the invalid time of a command control cycle; w is calculated through the motor speed feedback from the redundant electric steering machine 1; θ0 and θ1 are detected in real time by the angle sensor, and the chassis domain control is calculated based on the electrical signal feedback from the angle sensor; t2 is related to the characteristics of the entire steering system and needs to be determined based on the actual vehicle calibration; when Δθ exceeds the set threshold, the steering system has a fault risk.

[0034] In the embodiment of the present invention, the step of determining a steering system fault further includes: determining whether the system is faulty by detecting the steering system pressure, based on ΔP=P1-P0, Δθ1=θ-θ0, where P0 is the initial actual steering pressure of the wheel when the control command is issued; P1 is the actual wheel steering pressure when the command ends; ΔP is the difference in actual wheel steering pressure at the end of the control; θ is the target wheel angle; θ0 is the initial actual wheel angle when the control command is issued; Δθ1 is the difference between the target wheel angle and the initial wheel angle when the control command is issued; according to the characteristics of the steering system, It is necessary to calibrate a mapping curve of ΔP and Δθ1, where M is the deviation between the actually detected ΔP' and Δθ1' values ​​and the ΔP=P1-P0 and Δθ1=θ-θ0 curves (mapping curves). When M reaches the threshold, there is a risk of failure in the steering system. Finally, a weighted calculation is performed based on Δθ and M to determine whether the steering system is faulty, based on q=αΔθ+βM, where q is the probability of steering system failure, α is the Δθ weighting coefficient, β is the M weighting coefficient, and M is the deviation between the detected ΔP and Δθ1 values ​​and the set curve. When q is greater than the set threshold, it is determined that the steering system is faulty.

[0035] The present invention also provides an unmanned mining truck, comprising the redundant steering system. The left angle sensor 4 and the right angle sensor 5 in the present invention can be connected to the redundant electric steering gear 1 separately, that is, each set of electric steering gear is connected to an angle sensor; the redundant electric steering gear 1 can be a double stator single rotor or a double stator double rotor; the two-way angle sensor can be installed in the middle position of the steering front axle 7, or on the left and right steering rods, and the sensor type can be analog output and bus output, can be contact type and non-contact type, and can be a linear sensor.

[0036] The solution of the redundant electric steering gear 1 of the unmanned mining truck is a double-stator single-rotor solution, which has a compact structure, small size, little modification to the original vehicle, and can be quickly put into use; the steering column of the steering wheel 6 is installed above the redundant electric steering gear 1, and the redundant electric steering gear 1 is connected to the redundant full-hydraulic steering gear 2 below. The redundant full-hydraulic steering gear 2 drives the front axle steering by hydraulic pressure, and two-way angle sensors are respectively installed on the kingpins of the left and right wheels. The angle sensor sends the angle of wheel rotation to the chassis domain controller through an analog signal. The chassis domain controller receives the analog signal sent by the angle sensor and calculates the current actual angle of the wheel. The redundant electric steering gear 1 quickly controls the wheel to move to the target angle position by comparing the steering command issued by the chassis domain controller and the current actual angle of the wheel.

[0037] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, but not to limit the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims

1. A redundant steering system, characterized in that: The system includes a host computer, a chassis domain controller, a redundant electric steering gear, a redundant full hydraulic steering gear, a steering front axle, a pressure sensor, a left turn angle sensor and a right turn angle sensor; when working, the host computer sends a steering control instruction to the chassis domain controller, and the chassis domain controller sends the steering control instruction to the redundant electric steering gear according to the current actual state of the whole vehicle and controls the redundant full hydraulic steering gear to work at the same time, and the redundant electric steering gear drives the full hydraulic steering gear to drive the wheels to rotate, and the pressure sensor, the left turn angle sensor and the right turn angle sensor simultaneously feed back the current steering pressure and the actual wheel angle to the chassis domain controller; when the actual wheel angle reaches the target wheel angle, the redundant electric steering gear stops outputting; the redundant electric steering gear includes two electric steering gears, and the redundant full hydraulic steering gear includes two full hydraulic steering gears. When it is determined that the steering system fails, another electric steering gear or full hydraulic steering gear is used to work; The redundant electric steering gear and the redundant full hydraulic steering gear are mechanically connected, the redundant full hydraulic steering gear and the steering front axle are mechanically connected, the pressure sensor is installed in the hydraulic circuit between the redundant full hydraulic steering gear and the steering front axle, and the steering front axle directly drives the wheels to rotate; the host computer is an unmanned driving controller, and the host computer, the chassis domain controller, the redundant electric steering gear, the pressure sensor and the left / right turning angle sensor are electrically connected; The redundant electric steering gear has power supply redundancy, CAN bus redundancy, angle sensor redundancy and electric steering gear redundancy; when the vehicle is manually driven, the redundant electric steering gear performs power steering; when the vehicle is automatically driven, the redundant electric steering gear performs wire control steering and responds to the steering control command of the automatic driving; The redundant electric steering gear includes two motor controllers and two motors to form two sets of electric steering gears; the redundant electric steering gear has two independent power supplies, which are independent of each other and are respectively connected to the two sets of electric steering gears in the redundant electric steering gear; The redundant electric steering gear has two independent CAN buses, which are independent of each other and are respectively connected to two sets of electric steering gears in the redundant electric steering gear; the redundant electric steering gear has two independent angle sensors, which are respectively connected to the chassis domain controller, and the chassis domain controller sends the detected actual wheel angle to the redundant electric steering gear; The redundant full hydraulic steering gear is composed of two sets of full hydraulic steering gears, solenoid valves and pipeline parts, wherein the solenoid valves are controlled by the chassis domain controller and are used to switch the two sets of full hydraulic steering gears to work; under normal working conditions, one of the full hydraulic steering gears works; when the chassis domain controller detects a steering abnormality, the solenoid valve is energized, and the solenoid valve is switched to make the other full hydraulic steering gear work to ensure normal steering; The step of determining a steering system fault specifically includes: determining whether the steering system is abnormal based on a target wheel angle sent by the host computer and an actual wheel angle detected by a current angle sensor; The steps for determining a steering system failure also include: By detecting the steering system pressure, it is determined whether the system is faulty, and the M value is determined based on the ΔP=P1-P0 and Δθ1=θ-θ0 curves. M is the deviation value between the actually detected ΔP' and Δθ1' values ​​and the ΔP=P1-P0 and Δθ1=θ-θ0 curves. When M reaches a certain threshold, there is a risk of failure in the steering system; Performing weighted calculation based on Δθ and M to determine whether the steering system is faulty; including: based on q=αΔθ+βM, when q is greater than a set threshold, determining that the steering system is faulty; Wherein, P0 is the initial actual steering pressure of the wheel when the control command is issued; P1 is the actual wheel steering pressure when the command ends; ΔP is the difference between the actual wheel steering pressure at the end of the control; Δθ1 is the difference between the target wheel angle and the initial wheel angle when the control command is issued; q is the probability of steering system failure, α is the Δθ weighting coefficient, and β is the M weighting coefficient; The two electric steering gears are respectively the first electric steering gear and the second electric steering gear, and the two full hydraulic steering gears are respectively the first full hydraulic steering gear and the second full hydraulic steering gear; when the steering system fails, the first electric steering gear or the second electric steering gear, the first full hydraulic steering gear is judged to be faulty, and the chassis domain controller switches to the second full hydraulic steering gear; when the steering system fails, the first electric steering gear fails, and the chassis domain controller controls the second electric steering gear to work; when the steering system fails and the redundant electric steering gear works normally, the first full hydraulic steering gear may be faulty. After the chassis domain controller switches to the second full hydraulic steering gear, it is still judged that the steering system is faulty, then the redundant electric steering gear is faulty.

2. An unmanned mining truck, characterized in that: Comprising the redundant steering system of claim 1.

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