Redundant steering system and unmanned mining truck

Abstract

A redundant steering system and an unmanned mining truck, which belong to the field of steering systems and solve the problem of a redundant steering system failing to achieve full redundancy. The redundant steering system comprises an upper 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 steering angle sensor (4) and a right steering angle sensor (5), wherein the upper computer sends a steering control instruction to the chassis domain controller; on the basis of the current actual state of the truck, the chassis domain controller sends the steering control instruction to the redundant electric steering gear (1), and simultaneously controls the redundant full-hydraulic steering gear (2) to operate; the redundant electric steering gear (1) drives the redundant full-hydraulic steering gear (2) to drive wheels to rotate; and the pressure sensor (3), the left steering angle sensor (4) and the right steering angle sensor (5) simultaneously feed back a current steering pressure and an actual wheel steering angle to the chassis domain controller. By means of the redundancy design of the entire system, the steering system can meet autonomous driving requirements under any circumstances, thereby enhancing the stability and reliability of autonomous driving of the mining truck.

Description

A redundant steering system and an unmanned mining truck Technical Field

[0001] This invention belongs to the field of steering systems, and particularly relates to a redundant steering system and an unmanned mining truck. Background Technology

[0002] Due to the heavy loads of mining trucks, there are currently no electric steering systems on the market that can directly drive the wheels. Current solutions typically install the electric steering system on top of a fully hydraulic steering system, and this solution is based on this structure. Currently, redundant steering systems in unmanned mining trucks often use two steering systems to achieve steer-by-wire, resulting in complex structures, difficult installation and maintenance, and high control complexity. Furthermore, current redundant steering systems in unmanned mining trucks do not achieve complete redundancy; most only have redundant electric steering mechanisms. In other words, current redundant steering systems are structurally complex, difficult to install and maintain, and have a high failure rate; current redundant steering systems are complex to control, increasing the difficulty of use; and they do not achieve true full system redundancy. Therefore, there is a need to provide a redundant steering system and an unmanned mining truck to solve the above problems. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of the invention is to provide a redundant steering system and an unmanned mining truck, which solves the problems that the redundant steering system does not achieve complete redundancy and the steering system structure is complex.

[0004] This invention proposes a redundant steering system, comprising 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. During operation, the host computer sends steering control commands to the chassis domain controller. The chassis domain controller, based on the current vehicle status, sends steering control commands to the redundant electric steering gear and simultaneously controls the redundant full hydraulic steering gear. The redundant electric steering gear drives the full hydraulic steering gear to rotate the wheels. The pressure sensor, left turn angle sensor, and right turn angle sensor simultaneously feed back the current steering pressure and 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 power. The redundant electric steering gear comprises two electric steering gears, and the redundant full hydraulic steering gear comprises two full hydraulic steering gears. When a steering system malfunction is detected, the other electric steering gear or the full hydraulic steering gear is used.

[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 / right steering angle sensor are electrically connected.

[0006] Furthermore, the redundant electric steering system has power redundancy, CAN bus redundancy, angle sensor redundancy, and electric steering system redundancy; when manually driven, the redundant electric steering system provides power steering; when automatically driven, the redundant electric steering system provides steer-by-wire and responds to the steering control commands of the automatic driving system.

[0007] Furthermore, the redundant electric steering gear contains 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 independently connected to the two sets of electric steering gears in the redundant electric steering gear.

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

[0009] Furthermore, the redundant full hydraulic steering system consists of two full hydraulic steering systems, solenoid valves, and piping components. The solenoid valves are controlled by the chassis domain controller to switch the operation of the two full hydraulic steering systems. Under normal operating conditions, one of the full hydraulic steering systems operates. When the chassis domain controller detects a steering abnormality, it energizes the solenoid valve, which switches to allow the other full hydraulic steering system to operate, ensuring normal steering.

[0010] Further, the steps for determining a steering system malfunction specifically include: judging whether the steering system is abnormal by using the target wheel angle sent by the host computer and the actual wheel angle detected by the current steering angle sensor, based on θ = θ0 + wt, t = t1 - t2, Δθ = θ1 - θ, where 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 at the end of the control; w is the angular velocity of the wheel when steering; t is the effective steering time when the wheel is steering; t1 is the actual time consumed in a command control cycle; t2 is the invalid time of a command control cycle; w is calculated using the motor speed feedback from the redundant electric steering gear; θ0 and θ1 are detected in real time by the steering angle sensor; when Δθ exceeds the set threshold, the steering system is at risk of malfunction.

[0011] Furthermore, the steps for determining a steering system malfunction also include:

[0012] The system is judged to be faulty by detecting the pressure of the steering system. The value of M is determined based on the curves ΔP = P1 - P0 and Δθ1 = θ - θ0. M is the deviation of the actual detected ΔP' and Δθ1' values ​​from the curves ΔP = P1 - P0 and Δθ1 = θ - θ0. When M reaches a certain threshold, the steering system is at risk of failure.

[0013] The steering system is determined to be faulty by weighted calculation based on Δθ and M, including: based on q=αΔθ+βM, when q is greater than the set threshold, the steering system is determined to be faulty;

[0014] 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 between the actual wheel steering pressure when the control ends; Δθ1 is the difference between the target wheel angle and the initial wheel angle when the control command is issued; q is the steering system failure probability; α is the Δθ weighting coefficient; and β is the M weighting coefficient.

[0015] Furthermore, the two electric steering systems are designated as the first electric steering system and the second electric steering system, and the two fully hydraulic steering systems are designated as the first fully hydraulic steering system and the second fully hydraulic steering system. When the steering system malfunctions, either the first or second electric steering system is faulty, and the first fully hydraulic steering system is determined to be faulty. The chassis domain controller then switches to the second fully hydraulic steering system. When the steering system malfunctions, the first electric steering system malfunctions, and the chassis domain controller controls the second electric steering system to operate. When the steering system malfunctions, but the redundant electric steering system is operating normally, the first fully hydraulic steering system may malfunction. Even after the chassis domain controller switches to the second fully hydraulic steering system, it still determines that the steering system is faulty, in which case the redundant electric steering system is faulty.

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

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

[0018] 2. The system is simple, easy to control, and easy to install and maintain on-site. The debugging cycle is shortened, reducing personnel costs and human error. Attached Figure Description

[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. It is obvious that the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings.

[0020] Figure 1 is a structural schematic diagram of a redundant steering system according to an embodiment of the present invention;

[0021] Figure 2 is a flowchart of a redundant steering system according to an embodiment of the present invention;

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

[0023] Reference numerals: 1-Redundant electric steering gear, 2-Redundant full hydraulic steering gear, 3-Pressure sensor, 4-Left turn angle sensor, 5-Right turn angle sensor, 6-Steering wheel, 7-Steering front axle. Detailed Implementation

[0024] 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 with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that these descriptions are merely 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 those skilled in the art without creative effort should fall within the scope of protection of the present invention.

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

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

[0027] System Implementation Examples

[0028] As shown in Figures 1, 2, and 3, this invention provides a redundant steering system. The system comprises a host computer, a chassis domain controller, a redundant electric steering gear 1, a redundant fully hydraulic steering gear 2, a steering front axle 7, a pressure sensor 3, a left steering angle sensor 4, and a right steering angle sensor 5. The redundant electric steering gear 1 and the redundant fully hydraulic steering gear 2 are mechanically connected, as are the redundant fully hydraulic steering gear 2 and the steering front axle 7. The pressure sensor 3 is installed in the hydraulic circuit between the redundant fully hydraulic steering gear 2 and the steering front axle 7. The steering front axle 7 directly drives the wheels. The host computer is an unmanned driving controller, and the host computer, chassis domain controller, redundant electric steering gear 1, pressure sensor 3, and left / right steering angle sensors 5 are electrically connected. During operation, the host computer sends steering control commands to the chassis domain controller. The chassis domain controller, based on the current vehicle status, sends steering control commands to redundant electric steering gear 1 and simultaneously controls redundant full hydraulic steering gear 2. Redundant electric steering gear 1 drives the full hydraulic steering gear, causing the wheels to rotate. Pressure sensor 3, left steering angle sensor 4, and right steering angle sensor 5 simultaneously feed back the current steering pressure and actual wheel angle to the chassis domain controller. When the actual wheel angle reaches the target wheel angle, redundant electric steering gear 1 stops outputting power, and the full hydraulic steering gear also loses driving force, causing the wheel rotation to stop. Redundant electric steering gear 1 comprises two electric steering gears, and redundant full hydraulic steering gear 2 comprises two full hydraulic steering gears. When a steering system malfunction is detected, the other electric steering gear or the full hydraulic steering gear is used. Because all parts of the system have redundancy backups, when steering abnormalities occur during autonomous driving, the backup system can continue to respond to autonomous driving needs, and repairs can be performed after production ends.

[0029] In this embodiment of the invention, the two electric steering gears are a first electric steering gear (motor 1) and a second electric steering gear (motor 2), and the two fully hydraulic steering gears are a first fully hydraulic steering gear (steering gear 1) and a second fully hydraulic steering gear (steering gear 2). When the steering system malfunctions, either the first or second electric steering gear is faulty, and the first fully hydraulic steering gear is determined to be faulty. The chassis domain controller switches to the second fully hydraulic steering gear. When the steering system malfunctions, the first electric steering gear is faulty, and the chassis domain controller controls the second electric steering gear to operate. When the steering system malfunctions, but the redundant electric steering gear 1 is operating normally, it is possible that the first fully hydraulic steering gear is faulty. After the chassis domain controller switches to the second fully hydraulic steering gear, it still determines that the steering system is faulty, in which case the redundant electric steering gear 1 is faulty. For fault detection of the redundant electric steering gear 1, under normal circumstances, since the redundant electric steering gear 1 itself has a control chip, it can autonomously report its fault status in most cases. When the redundant electric steering gear 1 cannot report its fault status, the chassis domain controller can determine whether the redundant electric steering gear 1 is faulty through the CAN bus status or through the following methods.

[0030] In this embodiment of the invention, the redundant electric steering gear 1 has power redundancy, CAN bus redundancy, steering angle sensor redundancy, and electric steering gear redundancy. During manual driving, the redundant electric steering gear 1 provides power steering; during autonomous driving, it provides steer-by-wire, responding to steering control commands from the autonomous driving system. The redundant electric steering gear 1 internally includes two motor controllers and two motors, forming two sets of electric steering gears. The redundant electric steering gear 1 has two independent power supplies, each independently connected to one of the two sets of electric steering gears within the redundant electric steering gear 1. The redundant electric steering gear 1 also has two independent CAN buses, each independently connected to one of the two sets of electric steering gears within the redundant electric steering gear 1. Furthermore, the redundant electric steering gear 1 has two independent steering angle sensors, each connected to a chassis domain controller, which sends the detected actual wheel steering angle to the redundant electric steering gear 1.

[0031] In this embodiment of the invention, the redundant full hydraulic steering gear 2 consists of two full hydraulic steering gears, solenoid valves, and piping components. The solenoid valves are controlled by the chassis domain controller and are used to switch the operation of the two full hydraulic steering gears. Under normal operating conditions, one of the full hydraulic steering gears (steering gear 1) is in operation. When the chassis domain controller detects a steering abnormality, it energizes the solenoid valve, which switches to allow the other full hydraulic steering gear (steering gear 2) to operate, ensuring normal steering.

[0032] In this embodiment of the invention, when the chassis domain controller receives a steering control command from the host computer, it sends both 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. Under fault-free conditions, both sets of electric steering gears in the redundant electric steering gear 1 system drive simultaneously, increasing steering reliability. If one set of electric steering gears fails, the other set operates independently. When the chassis domain controller receives a steering control command from the host computer, it controls the redundant electric steering gear 1 to start working, and simultaneously controls the steering gear 1 in the redundant fully hydraulic steering gear 2 to operate. If steering gear 1 fails, it controls steering gear 2 to operate.

[0033] In this embodiment of the invention, the step of determining a steering system fault specifically includes: determining whether the steering system is abnormal by using the target wheel angle sent by the host computer and the actual wheel angle detected by the current steering angle sensor, based on θ = θ0 + wt, t = t1 - t2, Δθ = θ1 - θ, where 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 at the end of the control; w is the angular velocity of the wheel when steering; t is the effective steering time when the wheel is steering; t1 is the actual time consumed in a command control cycle; t2 is the invalid time of a command control cycle; w is calculated by the motor speed fed back by the redundant electric steering gear 1; θ0 and θ1 are detected in real time by the steering angle sensor, and the chassis domain control is calculated based on the electrical signal fed back by the steering angle sensor; t2 is related to the characteristics of the entire steering system and needs to be determined according to the actual vehicle calibration; when Δθ exceeds the set threshold, the steering system is at risk of failure.

[0034] In this embodiment of the invention, the step of determining a steering system fault further includes: judging 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 at the end of the command; ΔP is the difference between the 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... To calibrate a mapping curve between ΔP and Δθ1, M is the deviation of the actual detected ΔP' and Δθ1' values ​​from the curves ΔP = P1 - P0 and Δθ1 = θ - θ0 (the mapping curves). When M reaches a certain threshold, the steering system is at risk of failure. 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 weighting coefficient of Δθ, β is the weighting coefficient of M, and M is the deviation of the detected ΔP and Δθ1 values ​​from the set curves. When q is greater than the set threshold, the steering system is judged to be faulty.

[0035] This invention also provides an unmanned mining truck, which includes the aforementioned redundant steering system. The left and right steering angle sensors 5 in this invention can be individually connected to the redundant electric steering gear 1, meaning each electric steering gear is connected to one steering angle sensor. The redundant electric steering gear 1 can be a dual-stator single-rotor system or a dual-stator dual-rotor system. The two steering angle sensors can be installed in the middle of the steering front axle 7 or on the left and right steering tie rods. The sensor types can be analog output and bus output, contact and non-contact, and linear sensors.

[0036] The unmanned mining truck uses a dual-stator, single-rotor design for the redundant electric steering gear 1. This design is compact, small in size, requires minimal modification to the original vehicle, and can be quickly deployed. The steering wheel 6 and steering column are mounted above the redundant electric steering gear 1, which is connected to the redundant full hydraulic steering gear 2 below. The redundant full hydraulic steering gear 2 drives the front axle to steer hydraulically. Two steering angle sensors are mounted on the kingpins of the left and right wheels, respectively. The steering angle sensors transmit the wheel rotation angle to the chassis domain controller via analog signals. The chassis domain controller receives the analog signals from the steering angle sensors and calculates the current actual wheel angle. The redundant electric steering gear 1 quickly controls the wheels to move to the target angle position by comparing the steering command issued by the chassis domain controller with the current actual wheel angle.

[0037] The applicant of this invention has provided a detailed description of the embodiments of the invention in conjunction with the accompanying drawings. However, those skilled in the art should understand that the above embodiments are merely preferred embodiments of the invention. The detailed description is only intended to help readers better understand the spirit of the invention and is not intended to limit the scope of protection of the invention. On the contrary, any improvements or modifications made based on the inventive spirit of the invention should fall within the scope of protection of the 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, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A redundant steering system, characterized in that, The system comprises a host computer, a chassis domain controller, a redundant electric steering gear, a redundant full hydraulic steering gear, a steering front axle, pressure sensors, a left turn angle sensor, and a right turn angle sensor. During operation, the host computer sends steering control commands to the chassis domain controller. The chassis domain controller, based on the current vehicle status, sends steering control commands to the redundant electric steering gear and simultaneously controls the redundant full hydraulic steering gear. The redundant electric steering gear drives the full hydraulic steering gear, causing the wheels to rotate. The pressure sensor, left turn angle sensor, and right turn angle sensor simultaneously feed back the current steering pressure and 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 power. The redundant electric steering gear comprises two electric steering gears, and the redundant full hydraulic steering gear comprises two full hydraulic steering gears. When a steering system malfunction is detected, the other electric steering gear or the full hydraulic steering gear is used.

2. The redundant steering system according to claim 1, characterized in that, The redundant electric steering gear and the redundant full hydraulic steering gear are mechanically connected, and 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. The steering front axle directly drives the wheels to rotate. The host computer is an unmanned driving controller. The host computer, chassis domain controller, redundant electric steering gear, pressure sensor and left / right steering angle sensor are electrically connected.

3. A redundant steering system according to claim 1, characterized in that, The redundant electric steering system features power redundancy, CAN bus redundancy, angle sensor redundancy, and electric steering system redundancy. When manually driven, the redundant electric steering system provides power steering assistance; when automatically driven, the redundant electric steering system provides steer-by-wire and responds to steering control commands from the automatic driving system.

4. A redundant steering system according to claim 1, characterized in that, The redundant electric steering gear contains 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 independently connected to the two sets of electric steering gears in the redundant electric steering gear.

5. A redundant steering system according to claim 4, characterized in that, The redundant electric steering system has two independent CAN buses, which are independently connected to two sets of electric steering systems in the redundant electric steering system. The redundant electric steering system has two independent steering angle sensors, which are connected to the chassis domain controller. The chassis domain controller sends the detected actual wheel steering angle to the redundant electric steering system.

6. A redundant steering system according to claim 1, characterized in that, The redundant full hydraulic steering system consists of two full hydraulic steering systems, solenoid valves, and piping components. The solenoid valves are controlled by the chassis domain controller to switch the operation of the two full hydraulic steering systems. Under normal operating conditions, one of the full hydraulic steering systems is in operation. When the chassis domain controller detects a steering abnormality, it energizes the solenoid valve, which switches to allow the other full hydraulic steering system to operate, ensuring normal steering.

7. A redundant steering system according to claim 1, characterized in that, The steps for determining a steering system malfunction specifically include: judging whether the steering system is abnormal by comparing the target wheel angle sent by the host computer with the actual wheel angle detected by the current steering angle sensor, based on θ = θ0 + wt, t = t1 - t2, Δθ = θ1 - θ, where 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 at the end of the control; w is the angular velocity of the wheel when steering; t is the effective steering time when the wheel is steering; t1 is the actual time consumed in a command control cycle; t2 is the invalid time of a command control cycle; w is calculated using the motor speed feedback from the redundant electric steering gear; θ0 and θ1 are detected in real time by the steering angle sensor; when Δθ exceeds the set threshold, the steering system is at risk of malfunction.

8. A redundant steering system according to claim 7, characterized in that, The steps for diagnosing a steering system malfunction also include: The system is judged to be faulty by detecting the pressure of the steering system. The value of M is determined based on the curves ΔP = P1 - P0 and Δθ1 = θ - θ0. M is the deviation of the actual detected ΔP' and Δθ1' values ​​from the curves ΔP = P1 - P0 and Δθ1 = θ - θ0. When M reaches a certain threshold, the steering system is at risk of failure. The system performs a weighted calculation based on Δθ and M to determine whether the steering system is faulty; this includes: based on q = αΔθ + βM, when q is greater than a set threshold, the system is determined to be faulty. 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 between the actual wheel steering pressure when the control ends; Δθ1 is the difference between the target wheel angle and the initial wheel angle when the control command is issued; q is the steering system failure probability; α is the Δθ weighting coefficient; and β is the M weighting coefficient.

9. A redundant steering system according to claim 1, characterized in that, The system has two sets of electric steering gears, namely the first electric steering gear and the second electric steering gear, and two sets of fully hydraulic steering gears, namely the first fully hydraulic steering gear and the second fully hydraulic steering gear. When the steering system malfunctions, either the first electric steering gear or the second electric steering gear will be identified as the first fully hydraulic steering gear, and the chassis domain controller will switch to the second fully hydraulic steering gear. When the steering system malfunctions, specifically the first electric steering gear, the chassis domain controller will control the second electric steering gear to operate. If the steering system malfunctions but the redundant electric steering gear is working normally, the first fully hydraulic steering gear may be faulty. If the chassis domain controller switches to the second fully hydraulic steering gear and still determines that the steering system is faulty, then the redundant electric steering gear is faulty.

10. An unmanned mining truck, characterized in that, It includes the redundant steering system as described in any one of claims 1 to 9.

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