Device and method for measuring a side slip angle of an articulated vehicle

Abstract

The application discloses a kind of hinge type vehicle side slip angle measuring device and method, it is related to vehicle technical field, measuring device includes: inertial navigation system, first optical fiber gyroscope, angle acquisition unit and processing unit;Wherein, the gravity acceleration component of inertial navigation system is obtained to hinge type vehicle and angular velocity, the rotational angular velocity of first optical fiber gyroscope is obtained to rear vehicle body, angle acquisition unit obtains the hinge angle between front vehicle body and rear vehicle body, and processing unit is indirectly measured according to the gravity acceleration component, angular velocity, rotational angular velocity and hinge angle, and the centroid side slip angle of hinge type vehicle is obtained;Solve the current mine hinge type vehicle centroid side slip angle difficult problem of acquisition.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a device and method for calculating the sideslip angle of an articulated vehicle. Background Technology

[0002] Articulated vehicles, such as explosion-proof loaders, have advantages such as strong power, flexible steering, strong road adaptability, strong tunnel passability, and complete functions. They are widely used in narrow and winding working spaces such as underground coal mines.

[0003] To ensure that explosion-proof loaders can operate safely under various changing road conditions, it is necessary to accurately measure and estimate the vehicle's status. Among these parameters, the sideslip angle is the most important parameter for evaluating the vehicle's lateral motion behavior and achieving stability control. Sideslip angle information plays a crucial role in vehicle handling and safety control.

[0004] Because it is difficult to observe the lateral movement of explosion-proof loaders when they turn on typical unpaved roads in mines, the lateral stability of the vehicle can only be improved by controlling the center of gravity sideslip angle within an ideal range. Therefore, the calculation of the center of gravity sideslip angle is particularly important.

[0005] However, in the narrow and enclosed environment of underground coal mines, it is currently impossible to measure the heading angle using GPS signals, making satellite navigation data difficult to use. At the same time, it is also very difficult to directly measure the sideslip angle of the center of gravity of underground explosion-proof loaders. Similarly, for other articulated vehicles, if they operate in similar narrow and enclosed environments, the calculation of the sideslip angle faces the same problem. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for calculating the sideslip angle of an articulated vehicle, which can indirectly calculate the sideslip angle of the center of gravity of the articulated vehicle in a narrow and enclosed environment similar to that in a coal mine, thereby improving the accuracy and safety of vehicle control.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A device for calculating the sideslip angle of an articulated vehicle, the articulated vehicle comprising a front body and a rear body, the device comprising:

[0009] An inertial navigation system, installed on the articulated vehicle, is used to acquire the gravitational acceleration components and angular velocity of the articulated vehicle relative to three-dimensional inertial space.

[0010] A first fiber optic gyroscope is mounted on the rear vehicle body to obtain the rotational angular velocity of the rear vehicle body;

[0011] An angle acquisition unit is used to acquire the hinge angle between the front vehicle body and the rear vehicle body;

[0012] The processing unit, connected to the inertial navigation system, the first fiber optic gyroscope, and the angle acquisition unit, is used for:

[0013] The heading angle of the vehicle is obtained based on the gravitational acceleration components and angular velocity.

[0014] The heading angle of the rear vehicle is calculated based on the rotational angular velocity of the rear vehicle body;

[0015] Based on the hinge angle, obtain the angle between the rear vehicle body and the x-axis in the vehicle coordinate system;

[0016] The sideslip angle of the articulated vehicle is calculated based on the overall vehicle heading angle, the following vehicle heading angle, and the included angle.

[0017] Optionally, the measuring device further includes:

[0018] A second fiber optic gyroscope is mounted on the front vehicle body and is used to obtain the rotational angular velocity of the front vehicle body.

[0019] The vehicle speed measurement unit is used to obtain the first wheel speed and the second wheel speed of the front vehicle body;

[0020] The processing unit is also used for:

[0021] The heading angle of the front vehicle is calculated based on the rotational angular velocity of the front vehicle body;

[0022] Based on the heading angle of the front vehicle body, the rotational speed of the first wheel, and the rotational speed of the second wheel, the lateral velocity and longitudinal velocity at the center of gravity of the front vehicle are obtained.

[0023] The lateral and longitudinal velocities at the center of gravity of the rear vehicle are obtained based on the yaw rate of the front vehicle body, the yaw rate of the rear vehicle body, the hinge angle, and the lateral and longitudinal velocities at the center of gravity of the front vehicle body.

[0024] The tire slip angle of each tire of the articulated vehicle is calculated based on the lateral and longitudinal velocities at the center of gravity of the front vehicle and the center of gravity of the rear vehicle.

[0025] Optionally, the processing unit obtains the vehicle heading angle based on the gravitational acceleration component and angular velocity, specifically including:

[0026] The pitch and yaw angles of the articulated vehicle are calculated based on the gravitational acceleration components.

[0027] The vehicle heading angle is obtained based on the angular velocity, pitch angle, and yaw angle.

[0028] Optionally, the processing unit calculates the heading angle of the rear vehicle based on the rotational angular velocity of the rear vehicle body, using the following formula:

[0029]

[0030] Where η represents the heading angle of the rear vehicle, η0 is the initial heading angle of the rear vehicle body, and ω i (t) represents the rotational angular velocity at the i-th sampling moment within the preset time period, and n represents the total number of sampling moments within the preset time period. i Let t represent the i-th sampling time. i+1 This represents the (i+1)th sampling time.

[0031] Optionally, the processing unit obtains the angle α between the rear vehicle body and the x-axis in the vehicle coordinate system based on the hinge angle, using the following formula:

[0032]

[0033] Where δ represents the hinge angle, l f The distance l represents the distance from the hinge point to the center of the front axle. r This indicates the distance from the hinge point to the center of the rear axle.

[0034] Optionally, the processing unit calculates the sideslip angle of the articulated vehicle based on the overall vehicle heading angle, the following vehicle heading angle, and the included angle, using the following formula:

[0035] β = θ - (η + α);

[0036] Where β is the centroid sideslip angle, θ is the overall vehicle heading angle, η is the rear vehicle heading angle, and α is the angle between the rear vehicle body and the x-axis in the vehicle coordinate system.

[0037] Optionally, the lateral and longitudinal velocities at the center of gravity of the rear vehicle are obtained based on the yaw rate of the front vehicle body, the yaw rate of the rear vehicle body, the hinge angle, and the lateral and longitudinal velocities at the center of gravity of the front vehicle body. The formulas used include:

[0038]

[0039] Among them, v x2 The lateral velocity v represents the velocity at the center of gravity of the rear vehicle. y2 δ represents the longitudinal velocity at the center of gravity of the rear vehicle; δ represents the hinge angle; b is the distance between the center of gravity of the front vehicle and the hinge point; ω z1 Let ω be the yaw rate of the front of the vehicle. z2 denoted as yaw rate of the rear vehicle body; c is the distance between the center of mass of the rear vehicle body and the hinge point.

[0040]

[0041] Among them, v x1 The lateral velocity v represents the velocity at the center of gravity of the vehicle in front. y1 The longitudinal velocity at the center of gravity of the vehicle in front is represented by n1, the rotational speed of the first wheel is n2, and the rotational speed of the second wheel is θ. f R is the heading angle of the front vehicle body, and R is the rolling radius of each tire.

[0042] Optionally, the tire slip angles of each tire of the articulated vehicle are calculated based on the lateral and longitudinal velocities at the center of gravity of the front vehicle and the center of gravity of the rear vehicle. The formulas used include:

[0043]

[0044]

[0045]

[0046]

[0047] Wherein, β1, β2, β3, and β4 represent the first tire slip angle, the second tire slip angle, the third tire slip angle, and the fourth tire slip angle, respectively; L f1 L is the distance from the center of gravity of the front vehicle to the front axle. f2 B is the distance from the rear vehicle's center of gravity to the rear axle, and B is half the track width of the articulated vehicle.

[0048] Optionally, the processing unit obtains the vehicle heading angle based on the angular velocity, pitch angle, and yaw angle, using the following formula:

[0049]

[0050] Where θ represents the vehicle's heading angle, ω e Let ω be the Earth's angular velocity of rotation. x ω y and ω z denoted as angular velocities along the x-axis, y-axis, and z-axis, respectively; p is the pitch angle of the articulated vehicle; and r is the yaw angle of the articulated vehicle.

[0051] The formula for obtaining the pitch angle p is:

[0052] The formula for obtaining the yaw angle r is:

[0053] Among them, f x f y and f z These represent the gravitational components along the x-axis, y-axis, and z-axis, respectively.

[0054] The present invention also provides a method for calculating the sideslip angle of an articulated vehicle, the method comprising:

[0055] Obtain the gravitational acceleration components and angular velocity of the articulated vehicle relative to three-dimensional inertial space;

[0056] Obtain the rotational angular velocity of the rear vehicle body;

[0057] Obtain the hinge angle between the front vehicle body and the rear vehicle body;

[0058] The heading angle of the vehicle is obtained based on the gravitational acceleration components and angular velocity.

[0059] The heading angle of the rear vehicle is calculated based on the rotational angular velocity of the rear vehicle body;

[0060] Based on the hinge angle, obtain the angle between the rear vehicle body and the x-axis in the vehicle coordinate system;

[0061] The sideslip angle of the articulated vehicle is calculated based on the overall vehicle heading angle, the following vehicle heading angle, and the included angle.

[0062] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0063] Compared to existing technologies, this invention does not require GPS to acquire satellite navigation data. Instead, it acquires the gravitational acceleration components, angular velocity, rear body rotational angular velocity, and the articulation angle between the front and rear bodies of the articulated vehicle. Based on this data, the sideslip angle of the articulated vehicle is calculated, thus indirectly determining the sideslip angle. Subsequent control can then be based on this sideslip angle. Therefore, the technical solution provided by this invention can still be used in narrow, enclosed environments, thereby improving the accuracy and safety of vehicle control in such environments. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the measuring device provided in an embodiment of the present invention;

[0065] Figure 2 This is a schematic diagram of the actual installation position provided in an embodiment of the present invention;

[0066] Figure 3 This is a reference diagram for the vehicle coordinate system and angle calculation provided in an embodiment of the present invention;

[0067] Figure 4 This is an example diagram of the calculation process provided in an embodiment of the present invention;

[0068] Figure 5This is a schematic diagram of another module of the measuring device provided in an embodiment of the present invention;

[0069] Figure 6 This is a flowchart illustrating the measurement method provided in an embodiment of the present invention.

[0070] Symbol explanation:

[0071] Inertial navigation system-1, first fiber optic gyroscope-2, angle acquisition unit-3, processing unit-4, second fiber optic gyroscope-5, vehicle speed measurement unit-6. Detailed Implementation

[0072] The purpose of this invention is to provide a device and method for calculating the sideslip angle of an articulated vehicle. By indirectly calculating the sideslip angle of the center of gravity of the articulated vehicle, precise vehicle control can be achieved, thus ensuring driving safety.

[0073] The articulated vehicle includes a front body and a rear body. Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0074] like Figure 1 As shown, the above-mentioned measurement device specifically includes: an inertial navigation system 1, a first fiber optic gyroscope 2, an angle acquisition unit 3, and a processing unit 4.

[0075] An inertial navigation system 1 is installed on the articulated vehicle. The inertial navigation system 1 is used to acquire the gravitational acceleration components and angular velocities of the articulated vehicle relative to three-dimensional inertial space.

[0076] Taking the xyz coordinates to represent three-dimensional inertial space as an example, the gravitational acceleration components specifically include gravitational acceleration components in the x-axis, y-axis and z-axis directions.

[0077] like Figure 2 As shown, in one example, the aforementioned inertial navigation system 1 includes: a three-axis accelerometer and a three-axis gyroscope; the three-axis accelerometer measures the gravitational acceleration component of the articulated vehicle relative to inertial space in real time; the three-axis gyroscope measures the angular velocity of the articulated vehicle in real time.

[0078] When an inertial navigation system is installed on a vehicle, a calibration routine can be executed when the vehicle and the inertial navigation system are stationary. The position is initialized using the last known position before the vehicle starts moving, and the speed is initialized to zero.

[0079] For example, a three-axis accelerometer and a three-axis gyroscope can be installed at the front of the rear of the vehicle body. More specifically, a three-axis accelerometer and a three-axis gyroscope (such as a MEMS three-axis gyroscope) can be installed at the front of the rear of the vehicle body, close to the centerline of the vehicle body, and the distance from the centerline does not exceed one-sixth of the width of the vehicle body.

[0080] The first fiber optic gyroscope 2 is mounted on the rear of the vehicle. The first fiber optic gyroscope 2 is used to obtain the rotational angular velocity of the rear of the vehicle.

[0081] For example, the first fiber optic gyroscope 2 can be mounted on the floor at the left or right end of the rear vehicle body to measure the direction of the rear vehicle body.

[0082] Angle acquisition unit 3 is used to acquire the hinge angle between the front and rear vehicle bodies.

[0083] In one example, angle acquisition unit 3 may specifically be an angle sensor (see [reference]). Figure 2 An angle sensor is installed on the articulation shaft of an articulated vehicle to measure the articulation angle.

[0084] Specifically, the front end of the angle sensor bracket is connected to the front vehicle body, and the lower end of its coupling bracket is connected to the rear vehicle body. When the front and rear vehicle bodies of the articulated vehicle rotate, the articulation angle δ can be measured.

[0085] In another example, the angle acquisition unit 3 may include a camera module and an image processing module; wherein the camera module is used to acquire an image of the articulated joint of the vehicle; and the image processing module is used to perform image analysis based on the image acquired by the camera module and calculate the articulation angle.

[0086] Processing unit 4 is connected to inertial navigation system 1, first fiber optic gyroscope 2, and angle acquisition unit 3, respectively. Processing unit 4 is used for:

[0087] The heading angle of the vehicle is obtained based on the components of gravitational acceleration and angular velocity.

[0088] The heading angle of the rear vehicle is calculated based on the rotational angular velocity of the rear vehicle body;

[0089] Based on the hinge angle, obtain the angle between the rear vehicle body and the x-axis in the vehicle coordinate system;

[0090] The sideslip angle of the articulated vehicle's center of gravity is calculated based on the overall vehicle's heading angle, the following vehicle's heading angle, and the included angle.

[0091] The following can be referred to Figure 3 The processing procedure of processing unit 4 is further explained.

[0092] The processing unit 4 can acquire the vehicle heading angle in the following ways:

[0093] Step 1: Calculate the pitch and yaw angles of the articulated vehicle based on the gravitational acceleration components.

[0094] Step 2: Obtain the overall vehicle heading angle based on the angular velocity, pitch angle, and yaw angle.

[0095] In step 1 above, the pitch angle and yaw angle can be obtained, for example, using the following formulas:

[0096]

[0097]

[0098] In the formula, p represents the pitch angle, r represents the yaw angle; f x f y and f z These represent the gravitational components of the vehicle along the x, y, and z axes, respectively. The processing unit 4 can convert the measurements from the aforementioned triaxial accelerometers into specific force components in the local horizontal coordinate system, thereby obtaining f. x f y and f z .

[0099] In step 2 above, the angular velocity can specifically be the angular velocity of the vehicle coordinate system relative to the local horizontal coordinate system, and its calculation formula includes, for example:

[0100]

[0101] Where, ω e Let ω be the Earth's angular velocity of rotation. x ω y and ω z ω represents the angular velocities of the articulated vehicle along the x-axis, y-axis, and z-axis, respectively; p represents the pitch angle of the articulated vehicle; and r represents the yaw angle of the articulated vehicle.

[0102] Based on the above formula, Formula 1 for calculating the vehicle's heading angle θ can be:

[0103]

[0104] In other embodiments of the present invention, the heading angle θ of the entire vehicle can also be approximately calculated using calculation formula 2:

[0105] Calculation formula 2 is derived from calculation formula 1: Since the pitch and yaw angles are very small during vehicle movement, the following approximation can be obtained:

[0106]

[0107] Accordingly, the formula for calculating the vehicle's heading angle θ can be simplified to formula 2:

[0108]

[0109] In other embodiments of the present invention, the processing unit 4 in all the above embodiments may specifically use the following formula when calculating the heading angle of the rear vehicle:

[0110]

[0111] In the formula, η represents the current heading angle of the rear vehicle, η0 is the initial heading angle of the rear vehicle, t0 is the initial time of vehicle movement, t1 is the final time of vehicle movement, and ω i (t) represents the rotational angular velocity at the i-th sampling time, and n represents the total number of sampling times within the preset time period (from the initial sampling time to the current sampling time). This means that the rotational angular velocity is integrated once in each time interval, and then the integral results are added together to obtain the rotation angle within that preset time interval; t i Let t represent the i-th sampling time. i+1 This represents the (i+1)th sampling time.

[0112] The initial position and orientation of the rear vehicle can be obtained through the inertial navigation system 1. Furthermore, the angle between the rear vehicle and the X-axis of the geodetic coordinate system can be calculated by the processing unit 4 or other devices to obtain the initial heading angle η0.

[0113] It should be noted that when the rear of the vehicle moves away from the X-axis, ω i (t) is a positive value, and ω represents the movement of the rear vehicle body towards the X-axis. i (t) is negative. ω i (t) can be the real-time measurement value at the i-th sampling time, or the average value obtained by averaging the measured values ​​of rotational angular velocity between the i-th and i+1-th sampling times.

[0114] The sensor sampling interval can be flexibly set as needed, such as 0.5s, 1s, 2s, etc., which will not be elaborated here. n is determined by the duration of the preset time period and the sampling interval.

[0115] In other embodiments of the present invention, when the processing unit 4 in all the above embodiments obtains the angle α between the rear vehicle body and the x-axis in the vehicle coordinate system based on the hinge angle, it may use the following formula:

[0116]

[0117] Where δ is the hinge angle, l f The distance l represents the distance from the hinge point to the center of the front axle. r This indicates the distance from the hinge point to the center of the rear axle.

[0118] For information on the vehicle coordinate system, please refer to [link / reference]. Figure 3In the natural coordinate system XY axis, O represents the hinge point, O1 represents the center of gravity of the front vehicle, O2 represents the center of gravity of the rear vehicle, CG represents the center of gravity of the whole vehicle, CFA represents the center of the front axle, and CRA represents the center of the rear axle. The line connecting the center of the front axle and the center of the rear axle is taken as the x-axis, and CG is taken as the origin of the coordinate system. On the plane containing the XY axis, the straight line passing through the CG point and perpendicular to the x-axis is taken as the y-axis, and the straight line perpendicular to the x-axis and y-axis and passing through the CG point is taken as the z-axis, thus establishing the vehicle coordinate system.

[0119] In one embodiment, the processing unit 4 may use the following formula when calculating the sideslip angle of the center of gravity of the articulated vehicle:

[0120] β = θ - (η + α);

[0121] In the formula, β is the centroid sideslip angle, θ is the overall vehicle heading angle, η is the rear vehicle heading angle, and α is the angle between the rear vehicle body and the x-axis in the vehicle coordinate system.

[0122] The sideslip angle is usually the angle between the vehicle's actual heading and the direction the vehicle is pointing. By observing the changes in the sideslip angle during vehicle movement, the current driving status of the vehicle can be judged, thereby improving the vehicle's control precision and ensuring driving safety.

[0123] In summary, a schematic diagram for the overall calculation of the centroid sideslip angle can be found in [reference needed]. Figure 4 As shown.

[0124] Generally speaking, if the sideslip angle exceeds the preset range, it indicates that the vehicle's lateral acceleration has increased. If the tires cannot effectively provide the lateral force required for lateral stability, the vehicle may skid. In this case, it is necessary to maintain lateral stability by controlling the steering wheel, accelerator pedal, and brakes. If the sideslip angle is small (within the preset range), the vehicle's lateral acceleration is relatively small, and the vehicle's lateral stability is relatively good, allowing it to maintain straight-line driving and cornering stability better during driving.

[0125] Therefore, only by accurately estimating the sideslip angle can the lateral force of the wheels be effectively limited to a range that does not reach the saturation boundary, thereby achieving the effect of lateral stability control. The calculation device provided by this invention obtains the gravitational acceleration component, angular velocity, rear body rotation angular velocity, and articulation angle of the articulated vehicle, and further calculates the sideslip angle of the articulated vehicle indirectly based on the above data. The entire calculation process does not rely on satellite navigation data, and its application is not affected even in the narrow and enclosed environment of a mine.

[0126] In other embodiments of the present invention, the processing unit 4 in all the above embodiments can also monitor the obtained centroid sideslip angle in real time, and send an alarm signal when it exceeds the preset range; wherein, the alarm signal can be sent directly to the vehicle's own control system or to an additional alarm unit, thereby playing a warning role and further ensuring driving safety.

[0127] Furthermore, when a vehicle turns, the overall center of gravity shifts, causing the overall center of gravity sideslip angle to change, resulting in sideslip angles for the front or rear wheels. In the case of small sideslip angles, such as ±0.25 rad (approximately 14.33°), the tire sideslip angle is directly proportional to the tire lateral force. The tire lateral force affects the lateral acceleration of the vehicle's overall center of gravity, and the center of gravity sideslip angle increases with the increase of lateral acceleration. Therefore, changes in the center of gravity sideslip angle lead to tire sideslip angles, and the tire sideslip angles, in turn, affect changes in the center of gravity sideslip angle.

[0128] Therefore, in other embodiments of the present invention, the tire's center of gravity sideslip angle can be further measured indirectly.

[0129] To obtain the tire slip angle, please refer to [link / reference]. Figure 5 The aforementioned measuring device may further include: a second fiber optic gyroscope 5 and a vehicle speed measuring unit 6.

[0130] The second fiber optic gyroscope 5 is mounted on the front of the vehicle body. The second fiber optic gyroscope 5 is used to obtain the rotational angular velocity of the front of the vehicle body.

[0131] Specifically, the second fiber optic gyroscope 5 can be installed on the central axis of the front vehicle body.

[0132] The vehicle speed measurement unit 6 is used to obtain the rotational speed of the front vehicle body tires. Taking the front vehicle body as an example with two tires, the vehicle speed measurement unit 6 can be used to obtain the rotational speed of the first wheel (corresponding to the left tire) and the rotational speed of the second wheel (corresponding to the right tire). When the driver is sitting in the driver's seat, the left tire is located on the driver's left and the right wheel is located on the driver's right.

[0133] For example, the vehicle speed measurement unit 6 can be a wheel speed sensor (such as a magnetoelectric wheel speed sensor, Hall effect wheel speed sensor, wheel speed encoder, etc.) or an odometer. Specifically, it can be located close to the wheel rotation axis and installed on the left and right wheels of the front vehicle body to measure the rotation speed of the two wheels.

[0134] Furthermore, taking the use of a magnetoelectric wheel speed sensor as an example, the magnetoelectric wheel speed sensor includes a magnet and a coil. Specifically, the magnet can be installed on the wheel near the center of rotation, and the coil can be installed on both sides of the roadway.

[0135] In this embodiment, the processing unit 4 is also used to: calculate the tire slip angle of each tire of the articulated vehicle.

[0136] In one example, the tire slip angle can be calculated as follows:

[0137] (1) The heading angle of the front vehicle is calculated based on the rotational angular velocity of the front vehicle body.

[0138] The method for obtaining the heading angle of the preceding vehicle can be referred to the method for obtaining the heading angle of the following vehicle, and will not be repeated here.

[0139] (2) Based on the heading angle of the front vehicle body, the speed of the first wheel, and the speed of the second wheel, obtain the lateral velocity and longitudinal velocity at the center of gravity of the front vehicle.

[0140] Specifically, the aforementioned lateral and longitudinal velocities can be calculated using a differential drive model of the front vehicle body.

[0141] The differential drive model is a method for describing the planar motion of a vehicle. Based on the differential drive model, the lateral and longitudinal velocities can be calculated, for example, using the following formulas:

[0142]

[0143] Among them, v x1 The lateral velocity v represents the velocity at the center of gravity of the vehicle in front. y1 The longitudinal velocity at the center of gravity of the vehicle in front is represented by n1, the rotational speed of the first wheel is n2, and the rotational speed of the second wheel is θ. f R is the heading angle of the front vehicle body, and R is the rolling radius of each tire.

[0144] (3) Based on the yaw rate of the front vehicle body, the yaw rate of the rear vehicle body, the articulation angle, and the lateral and longitudinal velocities at the center of gravity of the front vehicle body, obtain the lateral and longitudinal velocities at the center of gravity of the rear vehicle body.

[0145] For example, the following formula can be used:

[0146]

[0147] Among them, v x2 The lateral velocity v represents the velocity at the center of gravity of the rear vehicle. y2 δ represents the longitudinal velocity at the center of gravity of the rear vehicle; δ represents the hinge angle; b is the distance between the center of gravity of the front vehicle and the hinge point; ω z1 Let ω be the yaw rate of the front of the vehicle. z2 ω is the yaw rate of the rear vehicle body; c is the distance between the center of mass of the rear vehicle body and the hinge point.

[0148] (4) The tire slip angle of each tire of the articulated vehicle is calculated based on the lateral and longitudinal velocities at the center of gravity of the front vehicle and the lateral and longitudinal velocities at the center of gravity of the rear vehicle.

[0149] For example, the following formula can be used:

[0150]

[0151]

[0152]

[0153]

[0154] Wherein, β1, β2, β3, and β4 represent the first tire slip angle, the second tire slip angle, the third tire slip angle (corresponding to the left tire of the rear vehicle), and the fourth tire slip angle (corresponding to the right tire of the rear vehicle), respectively; L f1 L is the distance from the center of gravity of the front vehicle to the front axle. f2 B is the distance from the rear vehicle's center of gravity to the rear axle, and B is half the track width of the articulated vehicle.

[0155] The measuring device provided in this embodiment of the invention indirectly obtains the center of gravity sideslip angle by utilizing the vehicle's heading angle θ, the rear vehicle's heading angle η, and the angle α between the rear vehicle and the x-axis. This solves the problem of the limited number of current methods for measuring the center of gravity sideslip angle of articulated mining vehicles and provides a reference for obtaining center of gravity sideslip angle data. Furthermore, since changes in the center of gravity sideslip angle lead to the generation of tire sideslip angle, and as mentioned above, the tire sideslip angle and the center of gravity sideslip angle are interconnected and mutually influential, the measuring device provided in this embodiment of the invention can also measure the tire sideslip angle, further ensuring precise vehicle control and driving safety.

[0156] Wherein, the distance l from the hinge point to the center of the front axle f The distance l from the hinge point to the center of the rear axle r The distance L from the center of gravity of the front vehicle to the front axle f1 The distance L from the rear vehicle's center of gravity to the rear axle f2 The following are vehicle configuration parameters: the distance b between the center of gravity of the front vehicle body and the articulation point; the rolling radius R of each tire; the half track width B of the articulated vehicle; and the overall wheelbase. The yaw rate ω of the front vehicle body is also considered. z1 ω, the yaw rate of the rear vehicle z2 These are vehicle status parameters.

[0157] In other embodiments of the present invention, the above-mentioned vehicle configuration parameters may further include vehicle weight. Vehicle weight can be used to estimate the aforementioned... Figure 3The vehicle's center of gravity (CG) is calculated in the figure. The vehicle's center of gravity can be estimated by processing unit 4, but it can also be estimated by a device other than the calculation unit. It should be noted that vehicle configuration parameters can be obtained by processing unit 4 or by a parameter acquisition unit (such as an onboard parameter measurement sensor) and then transmitted to processing unit 4. Similarly, vehicle status parameters can be obtained by processing unit 4 or by a parameter acquisition unit and then transmitted to processing unit 4. The parameter acquisition unit can be connected to the vehicle data bus (such as a CAN data bus) to collect vehicle status parameters. The parameter acquisition unit can be part of the calculation device or exist independently. For example, the parameter acquisition unit can be a 32-channel LMS-SCADAS data acquisition system.

[0158] The processing unit 4 exemplarily includes at least one of a processor, a remote computer, a host computer, and a server (e.g., a cloud server, a local server); of course, the various functions of the processing unit 4 can also be achieved by making corresponding improvements to the vehicle's own control system. When the parameter acquisition unit is part of the above-mentioned calculation device, it can specifically be part of the processing unit 4. That is, in addition to the processor, remote computer, host computer, and server mentioned above, the processing unit 4 may also include a parameter acquisition unit.

[0159] Further, see Figure 6 Corresponding to the aforementioned measuring device, this embodiment of the invention also provides a method for measuring the sideslip angle of an articulated vehicle, which exemplarily includes:

[0160] Step S01: Obtain the gravitational acceleration components and angular velocity of the articulated vehicle relative to three-dimensional inertial space.

[0161] This step S01 can be performed by the aforementioned inertial navigation system 1. For details, please refer to the above description, which will not be repeated here.

[0162] Step S02: Obtain the rotational angular velocity of the rear vehicle body.

[0163] This step S02 can be performed by the aforementioned first fiber optic gyroscope 2. For details, please refer to the above description, which will not be repeated here.

[0164] Step S03: Obtain the hinge angle between the front and rear vehicle bodies.

[0165] This step S02 can be performed by the aforementioned angle acquisition unit 3. For details, please refer to the above description, which will not be repeated here.

[0166] Step S04: Obtain the vehicle heading angle based on the gravitational acceleration component and angular velocity.

[0167] Step S05: Calculate the heading angle of the rear vehicle based on the rotational angular velocity of the rear vehicle body.

[0168] Step S06: Based on the hinge angle, obtain the angle between the rear vehicle body and the x-axis in the vehicle coordinate system.

[0169] Step S07: Calculate the sideslip angle of the articulated vehicle's center of gravity based on the overall vehicle's heading angle, the following vehicle's heading angle, and the included angle.

[0170] The above steps S04-S07 can be executed by the aforementioned processing unit 4. For details, please refer to the above description, which will not be repeated here.

[0171] Regarding obtaining the aforementioned tire slip angle, the above calculation method may also include the following steps:

[0172] Step S08: Obtain the rotational angular velocity of the front vehicle body.

[0173] This step S08 can be performed by the aforementioned second fiber optic gyroscope 5. For details, please refer to the above introduction, and it will not be repeated here.

[0174] Step S09: Obtain the first wheel speed and the second wheel speed of the front vehicle body.

[0175] This step S09 can be performed by the aforementioned vehicle speed measurement unit 6. For details, please refer to the above description, which will not be repeated here.

[0176] Step S10: Calculate the heading angle of the front vehicle based on the rotational angular velocity of the front vehicle body.

[0177] Step S11: Based on the heading angle of the front vehicle body, the rotational speed of the first wheel, and the rotational speed of the second wheel, obtain the lateral velocity and longitudinal velocity at the center of gravity of the front vehicle.

[0178] Step S12: Based on the yaw rate of the front vehicle body, the yaw rate of the rear vehicle body, the articulation angle, and the lateral and longitudinal velocities at the center of gravity of the front vehicle body, obtain the lateral and longitudinal velocities at the center of gravity of the rear vehicle body.

[0179] Step S13: Calculate the tire slip angle of each tire of the articulated vehicle based on the lateral and longitudinal velocities at the center of gravity of the front vehicle and the center of gravity of the rear vehicle.

[0180] The above steps S10-S13 can be executed by the aforementioned processing unit 4. For details, please refer to the above description, which will not be repeated here.

[0181] In summary, the device and method for calculating the sideslip angle of articulated vehicles provided in the embodiments of the present invention can indirectly obtain the sideslip angle of the center of gravity and the tire sideslip angle of the articulated vehicle, thereby enabling better vehicle control and ensuring driving safety.

[0182] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0183] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A device for calculating the sideslip angle of an articulated vehicle, the articulated vehicle comprising a front body and a rear body, characterized in that, The measuring device includes: An inertial navigation system, installed on the articulated vehicle, is used to acquire the gravitational acceleration components and angular velocity of the articulated vehicle relative to three-dimensional inertial space. A first fiber optic gyroscope is mounted on the rear vehicle body to obtain the rotational angular velocity of the rear vehicle body; An angle acquisition unit is used to acquire the hinge angle between the front vehicle body and the rear vehicle body; The processing unit, connected to the inertial navigation system, the first fiber optic gyroscope, and the angle acquisition unit, is used for: The heading angle of the vehicle is obtained based on the gravitational acceleration components and angular velocity. The heading angle of the rear vehicle is calculated based on the rotational angular velocity of the rear vehicle body; Based on the hinge angle, obtain the angle between the rear vehicle body and the x-axis in the vehicle coordinate system; The sideslip angle of the articulated vehicle is calculated based on the overall vehicle heading angle, the following vehicle heading angle, and the included angle.

2. The device for calculating the side slip angle of an articulated vehicle according to claim 1, characterized in that, The measuring device further includes: A second fiber optic gyroscope is mounted on the front vehicle body and is used to obtain the rotational angular velocity of the front vehicle body. The vehicle speed measurement unit is used to obtain the first wheel speed and the second wheel speed of the front vehicle body; The processing unit is also used for: The heading angle of the front vehicle is calculated based on the rotational angular velocity of the front vehicle body; Based on the heading angle of the front vehicle body, the rotational speed of the first wheel, and the rotational speed of the second wheel, the lateral velocity and longitudinal velocity at the center of gravity of the front vehicle are obtained. The lateral and longitudinal velocities at the center of gravity of the rear vehicle are obtained based on the yaw rate of the front vehicle body, the yaw rate of the rear vehicle body, the hinge angle, and the lateral and longitudinal velocities at the center of gravity of the front vehicle body. The tire slip angle of each tire of the articulated vehicle is calculated based on the lateral and longitudinal velocities at the center of gravity of the front vehicle and the center of gravity of the rear vehicle.

3. The device for calculating the side slip angle of an articulated vehicle according to claim 1, characterized in that, The processing unit obtains the vehicle heading angle based on the gravitational acceleration component and angular velocity, specifically including: Based on the gravitational acceleration components, the pitch angle and yaw angle of the articulated vehicle are calculated. The vehicle heading angle is obtained based on the angular velocity, pitch angle, and yaw angle.

4. The device for calculating the side slip angle of an articulated vehicle according to claim 1, characterized in that, The processing unit calculates the heading angle of the rear vehicle based on the rotational angular velocity of the rear vehicle body, using the following formula: ； in, Indicates the heading angle of the rear vehicle. 0 is the initial heading angle of the rear vehicle. (t) represents the rotational angular velocity at the i-th sampling moment within the preset time period, and n represents the total number of sampling moments within the preset time period. i Let t represent the i-th sampling time. i+1 This represents the (i+1)th sampling time.

5. The device for calculating the side slip angle of an articulated vehicle according to claim 1, characterized in that, The processing unit obtains the angle α between the rear vehicle body and the x-axis in the vehicle coordinate system based on the hinge angle, using the following formula: ； Where δ represents the hinge angle, l f The distance l represents the distance from the hinge point to the center of the front axle. r This indicates the distance from the hinge point to the center of the rear axle.

6. The articulated vehicle sideslip angle measuring device according to claim 1, characterized in that, The processing unit calculates the sideslip angle of the articulated vehicle based on the overall vehicle heading angle, the following vehicle heading angle, and the included angle. The formula used is: β = θ - (η + α); Where β is the centroid sideslip angle, θ is the overall vehicle heading angle, η is the rear vehicle heading angle, and α is the angle between the rear vehicle body and the x-axis in the vehicle coordinate system.

7. The device for calculating the side slip angle of an articulated vehicle according to claim 2, characterized in that, The lateral and longitudinal velocities at the center of gravity of the rear vehicle are obtained based on the yaw rate of the front vehicle body, the yaw rate of the rear vehicle body, the hinge angle, and the lateral and longitudinal velocities at the center of gravity of the front vehicle body. The formulas used include: ； Among them, v x2 The lateral velocity v represents the velocity at the center of gravity of the rear vehicle. y2 δ represents the longitudinal velocity at the center of gravity of the rear vehicle; δ represents the hinge angle; b is the distance between the center of gravity of the front vehicle and the hinge point; ω z1 Let ω be the yaw rate of the front of the vehicle. z2 denoted as yaw rate of the rear vehicle body; c is the distance between the center of mass of the rear vehicle body and the hinge point. ； Among them, v x1 The lateral velocity v represents the velocity at the center of gravity of the vehicle in front. y1 The longitudinal velocity at the center of gravity of the vehicle in front is represented by n1, the rotational speed of the first wheel is n2, and the rotational speed of the second wheel is θ. f R is the heading angle of the front vehicle body, and R is the rolling radius of each tire.

8. The device for calculating the side slip angle of an articulated vehicle according to claim 2, characterized in that, The tire slip angles of each tire of the articulated vehicle are calculated based on the lateral and longitudinal velocities at the center of gravity of the front vehicle and the rear vehicle. include: ； ； ； ； Wherein, β1, β2, β3, and β4 represent the first tire slip angle, the second tire slip angle, the third tire slip angle, and the fourth tire slip angle, respectively; L f1 L is the distance from the center of gravity of the front vehicle to the front axle. r1 B is the distance from the rear vehicle's center of gravity to the rear axle, and B is half the track width of the articulated vehicle.

9. The device for calculating the sideslip angle of an articulated vehicle according to claim 3, characterized in that, The processing unit obtains the vehicle heading angle based on the angular velocity, pitch angle, and yaw angle, using the following formula: ； Where θ represents the vehicle's heading angle, ω x ω y and ω z denoted as angular velocities along the x-axis, y-axis, and z-axis, respectively; p is the pitch angle of the articulated vehicle; and r is the yaw angle of the articulated vehicle. The formula for obtaining the pitch angle p is: ; The formula for obtaining the yaw angle r is: ; Among them, f x f y and f z These represent the gravitational components along the x-axis, y-axis, and z-axis, respectively.

10. A method for calculating the sideslip angle of an articulated vehicle, the articulated vehicle comprising a front body and a rear body, characterized in that, The calculation method includes: Obtain the gravitational acceleration components and angular velocity of the articulated vehicle relative to three-dimensional inertial space; Obtain the rotational angular velocity of the rear vehicle body; Obtain the hinge angle between the front vehicle body and the rear vehicle body; The heading angle of the vehicle is obtained based on the gravitational acceleration components and angular velocity. The heading angle of the rear vehicle is calculated based on the rotational angular velocity of the rear vehicle body; Based on the hinge angle, obtain the angle between the rear vehicle body and the x-axis in the vehicle coordinate system; The sideslip angle of the articulated vehicle is calculated based on the overall vehicle heading angle, the following vehicle heading angle, and the included angle.

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