Driving control method and system of floatable vehicle and floatable vehicle

Abstract

The invention discloses a driving control method and system of a floatable vehicle and the floatable vehicle, and the driving control method comprises the steps that when the vehicle is in a floating state, according to the target yaw velocity and the actual yaw velocity of the vehicle and the pre-control target wheel speed and the actual wheel speed of each wheel of the vehicle, the pre-control target wheel speed and the actual wheel speed of each wheel of the vehicle are calculated; determining a pre-control torque and a torque correction amount of each wheel of the vehicle by adopting a motion control algorithm; and according to the pre-control torque and the torque correction amount of each wheel of the vehicle, target torque output by a motor corresponding to each wheel of the vehicle is determined so as to control the vehicle to run. On the basis of a double-closed-loop control scheme of a wheel speed closed loop and a yaw velocity closed loop, a complete double-closed-loop control loop composed of the wheel speed and the yaw velocity, feedforward control formed by pre-control torque / wheel speed and controller feedback control is formed, and good control precision and control response characteristics are achieved.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically to a driving control method and system of a floatable vehicle, and a floatable vehicle. Background Art

[0002] In people's daily lives, cars, as an important means of transportation, have greatly facilitated people's travel and have long become indispensable. However, existing cars can usually only travel on land, and their wading ability is weak. The generally allowed wading height is 300-400mm. Even for off-road vehicles, the allowed wading height does not exceed 900-1000mm. In recent years, heavy rainfall has caused problems such as road waterlogging, urban waterlogging, and flooded underground garages. The vehicles involved can only watch helplessly as they become flooded vehicles. Vehicle failures and even casualties occurred after wading.

[0003] In view of this, the need to develop a vehicle that can float in water like a boat is becoming increasingly urgent. In the related art, the control strategy of amphibious vehicles usually only distinguishes between normal driving mode and wading driving mode. However, when an amphibious vehicle is in a floating state, it is impossible to control the posture of the entire vehicle through torque control alone. Therefore, how to improve the control accuracy and control response characteristics of a floating vehicle is an urgent problem to be solved. Summary of the invention

[0004] The present application is proposed to solve at least one of the above problems. According to the first aspect of the present application, a driving control method for a floatable vehicle is provided, wherein the vehicle is independently driven by four motors, and the driving control method comprises: when the vehicle is in a floating state, according to the target yaw rate and actual yaw rate of the vehicle, and the pre-controlled target wheel speed and actual wheel speed of each wheel of the vehicle, a motion control algorithm is used to determine the pre-controlled torque and torque correction of each wheel of the vehicle; according to the pre-controlled torque and the torque correction of each wheel of the vehicle, the target torque output of the motor corresponding to each wheel of the vehicle is determined to control the driving of the vehicle.

[0005] In one embodiment of the present application, a motion control algorithm is used to determine the pre-controlled torque and torque correction of each wheel of the vehicle based on the target yaw angular velocity and actual yaw angular velocity of the vehicle, as well as the pre-controlled target wheel speed and actual wheel speed of each wheel of the vehicle, including: using a first motion control algorithm to determine the target wheel speed correction of each wheel of the vehicle based on the target yaw angular velocity and actual yaw angular velocity of the vehicle; using a second motion control algorithm to determine the pre-controlled torque and torque correction of each wheel of the vehicle based on the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle.

[0006] In one embodiment of the present application, when the vehicle is in the floating state and is not turning in place, the target wheel speed correction amount of each wheel of the vehicle is determined by using a first motion control algorithm based on the target yaw velocity and the actual yaw velocity of the vehicle, including: determining the target yaw velocity of the vehicle based on a preset steering wheel angle-vehicle speed-target yaw velocity relationship according to the steering wheel angle and the vehicle speed of the vehicle; and determining the target wheel speed correction amount of each wheel of the vehicle based on the target yaw velocity and the actual yaw velocity of the vehicle by using the first motion control algorithm.

[0007] In one embodiment of the present application, the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle are determined by a second motion control algorithm, including: determining the pre-controlled target wheel speed and pre-controlled torque of each wheel of the vehicle based on a preset throttle-target wheel speed-motor pre-controlled torque relationship according to the throttle of the vehicle; determining the torque correction of each wheel of the vehicle by a second motion control algorithm according to the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle.

[0008] In one embodiment of the present application, when the vehicle is in the floating state and turning on the spot in the driver mode, the target wheel speed correction amount of each wheel of the vehicle is determined by using a first motion control algorithm based on the target yaw velocity and the actual yaw velocity of the vehicle, including: determining the current target yaw velocity of the vehicle based on a preset throttle-yaw velocity increment relationship according to the throttle and the initial target yaw velocity of the vehicle; and determining the target wheel speed correction amount of each wheel of the vehicle based on the current target yaw velocity and the actual yaw velocity of the vehicle using the first motion control algorithm.

[0009] In one embodiment of the present application, the pre-control target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle are determined by a second motion control algorithm, including: determining the pre-control target wheel speed and pre-control torque of each wheel of the vehicle based on a preset target yaw angular velocity-target wheel speed-motor pre-control torque relationship according to the target yaw angular velocity of the vehicle; determining the torque correction of each wheel of the vehicle by using the second motion control algorithm according to the pre-control target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle.

[0010] In one embodiment of the present application, when the vehicle is in the floating state and turning on the spot in the automatic mode, the target wheel speed correction amount of each wheel of the vehicle is determined by using a first motion control algorithm based on the target yaw angular velocity and the actual yaw angular velocity of the vehicle, including: determining the target wheel speed correction amount of each wheel of the vehicle by using the first motion control algorithm based on the target yaw angular velocity, the actual yaw angular velocity and the target turning angle of the vehicle.

[0011] In one embodiment of the present application, the pre-control target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle are determined by a second motion control algorithm, including: determining the pre-control target wheel speed and pre-control torque of each wheel of the vehicle based on a preset target yaw angular velocity-target wheel speed-motor pre-control torque relationship according to the target yaw angular velocity of the vehicle; determining the torque correction of each wheel of the vehicle by using the second motion control algorithm according to the pre-control target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle.

[0012] In one embodiment of the present application, the drive control method further includes: judging whether the vehicle is in a floating state according to the wading depth, slip state and load state of each wheel suspension of each wheel of the vehicle.

[0013] In one embodiment of the present application, judging whether the vehicle is in a floating state based on the wading depth of each wheel of the vehicle, the slipping state and the load state of the suspension of each wheel includes: judging that the vehicle is in the floating state when the wading depth values ​​of each wheel of the vehicle are greater than the vehicle floating threshold, the suspension of each wheel is in an unloading state, and each wheel is in a slipping state.

[0014] In one embodiment of the present application, the drive control method further includes: when a request to enter a floating mode is received and the vehicle meets preset conditions, adopting a wading driving control strategy to control the driving of the vehicle; in the process of adopting the wading driving control strategy to control the driving of the vehicle, determining whether the vehicle is in the floating state.

[0015] In one embodiment of the present application, the drive control method also includes: detecting whether a floating function of the vehicle has a floating failure; when a floating failure is detected in the floating function of the vehicle and the vehicle is in the floating state, using the wading driving control strategy to control the driving of the vehicle.

[0016] In one embodiment of the present application, the preset conditions include at least: the vehicle speed is less than a preset threshold; the synchronization lock of the vehicle is in an unlocked state; when the floatable vehicle has an engine, the engine is in a started state, and the circuits where the carbon canister solenoid valve and the DMTL solenoid valve of the vehicle are located are both in a closed state.

[0017] In one embodiment of the present application, the use of a wading driving control strategy to control the driving of the vehicle includes: using a torque average distribution method to determine the target torque output by the motor corresponding to each wheel of the vehicle.

[0018] According to a second aspect of the present application, a drive control device for a floatable vehicle is also provided, the drive control device comprising: a first calculation module and a second calculation module; wherein the first calculation module is used to: when the vehicle is in a floating state, according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle, and the pre-controlled target wheel speed and the actual wheel speed of each wheel of the vehicle, adopt a motion control algorithm to determine the pre-controlled torque and torque correction amount of each wheel of the vehicle; the second calculation module is used to: when the vehicle is in the floating state, according to the pre-controlled torque and the torque correction amount of each wheel of the vehicle, determine the target torque output by the motor corresponding to each wheel of the vehicle to control the driving of the vehicle.

[0019] According to the third aspect of the present application, a drive control system for a floatable vehicle is also provided, and the drive control system for the floatable vehicle includes: a storage medium and a processor, and the storage medium stores a computer program run by the processor, and when the computer program is run by the processor, the processor executes any one of the above-mentioned drive control methods for the floatable vehicle.

[0020] According to a fourth aspect of the present application, a storage medium is further provided, on which a computer program is stored. When the computer program is run, it executes any one of the above-mentioned drive control methods for a floatable vehicle.

[0021] According to a fifth aspect of the present application, a floatable vehicle is further provided, the floatable vehicle comprising: a vehicle body, and a drive control system of any one of the above-mentioned floatable vehicles arranged on the vehicle body.

[0022] According to the driving control method and system of the floatable vehicle and the floatable vehicle provided by the embodiment of the present application, for a vehicle driven by four motors independently, when it is detected that the vehicle is in a floating state, a motion control algorithm is used to determine the pre-control torque and torque correction of each wheel of the vehicle according to the target yaw angular velocity and actual yaw angular velocity of the vehicle, as well as the pre-control target wheel speed and actual wheel speed of each wheel of the vehicle; then, according to the pre-control torque and torque correction of each wheel of the vehicle, the target torque output of the motor corresponding to each wheel of the vehicle is determined to control the driving of the vehicle. Based on the double closed-loop control scheme of wheel speed closed loop and yaw angular velocity closed loop, a complete double closed-loop control loop composed of wheel speed and yaw angular velocity, feedforward control formed by pre-control torque / wheel speed and controller feedback control is formed, which has good control accuracy and control response characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0024] Figure 1 This is a flow chart of a driving control method of a floatable vehicle according to an embodiment of the present invention;

[0025] Figure 2 This is a flow chart showing a method of determining whether a vehicle meets a preset condition according to an embodiment of the present invention;

[0026] Figure 3 This is a flow chart showing a method of determining whether a vehicle is in a floating state according to an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of a process flow of mutual conversion between different state sub-modes in a floating mode according to an embodiment of the present invention;

[0028] Figure 5 A schematic block diagram of switching between a wading state sub-mode and a floating state sub-mode according to an embodiment of the present invention;

[0029] Figure 6 A schematic diagram of measuring the wading depth of a wheel according to an embodiment of the present invention;

[0030] Figure 7 A control calculation flow chart of a floating driving control strategy in a floating driving control state shown in one embodiment of the present invention;

[0031] Figure 8A control calculation flow chart of a driving control strategy for a floating on-the-spot steering control state in a driver mode according to an embodiment of the present invention;

[0032] Fig. 9 A control calculation flow chart of a driving control strategy for a floating on-site steering control state in an automatic mode according to an embodiment of the present invention;

[0033] Fig.10 This is a schematic block diagram of the structure of a drive control system for a floatable vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0035] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0036] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0037] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0038] In order to fully understand the present invention, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0039] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0040] First, it is necessary to introduce the application scenario of the driving control method of the floatable vehicle in this application. The driving control method of the floatable vehicle is applied to the driving control process of the floatable vehicle traveling in the water. Among them, the floatable vehicle can be, for example, but not limited to, a vehicle that is driven by wheels alone for floating on water, the floatable vehicle can be a distributed drive vehicle with four motors independently driven, the floatable vehicle can have engine components or not, and the floatable vehicle can be, for example, but not limited to, a pure electric vehicle, a fuel vehicle, a plug-in hybrid vehicle, and an extended-range hybrid vehicle.

[0041] refer to Figure 1 , an embodiment of the present application provides a driving control method for a floatable vehicle, the driving control method comprising:

[0042] Step 1: When the vehicle is in a floating state, a motion control algorithm is used to determine a pre-control torque and a torque correction amount of each wheel of the vehicle according to the target yaw rate and the actual yaw rate of the vehicle, and the pre-control target wheel speed and the actual wheel speed of each wheel of the vehicle;

[0043] Step 2: According to the pre-control torque and torque correction of each wheel of the vehicle, determine the target torque output by the motor corresponding to each wheel of the vehicle to control the driving of the vehicle.

[0044] In the above scheme, for a vehicle driven by four motors independently, when it is detected that the vehicle is in a floating state, a motion control algorithm is used to determine the pre-control torque and torque correction of each wheel of the vehicle according to the target yaw rate and actual yaw rate of the vehicle, as well as the pre-control target wheel speed and actual wheel speed of each wheel of the vehicle; then, according to the pre-control torque and torque correction of each wheel of the vehicle, the target torque output of the motor corresponding to each wheel of the vehicle is determined to control the driving of the vehicle. Based on the double closed-loop control scheme of wheel speed closed loop and yaw rate closed loop, a complete double closed-loop control loop composed of wheel speed and yaw rate, feedforward control formed by pre-control torque / wheel speed and controller feedback control is formed, which has good control accuracy and control response characteristics. The above steps are described in detail below with reference to the accompanying drawings.

[0045] Exemplarily, the driving control method may further include: when a request to enter a floating mode is received and the vehicle meets preset conditions, adopting a wading driving control strategy to control the vehicle's driving; in the process of adopting the wading driving control strategy to control the vehicle's driving, determining whether the vehicle is in a floating state.

[0046] refer to Figure 2 , upon receiving a request to enter the floating mode, determine whether the vehicle meets the preset conditions for entering the floating mode, wherein the floating mode at least includes a wading state sub-mode and a floating state sub-mode. There are multiple ways to determine the preset conditions. Exemplarily, the preset conditions may at least include: the vehicle speed is less than a preset threshold, and the vehicle's synchronization lock is in an unlocked state; when the floatable vehicle has an engine, the engine is in a started state, and the circuits where the vehicle's carbon canister solenoid valve and DMTL solenoid valve are located are in a closed state. Maintain the safety of the entire vehicle, especially the key components, when using the wading water.

[0047] When determining whether the vehicle meets the preset conditions for entering the floating mode, a variety of methods can be used, as follows: Figure 2 Several judgment methods are introduced as examples.

[0048] S00: Start.

[0049] S01: Obtain the button status information of the floating mode, and determine whether the driver has issued a floating mode switch request instruction. The floating mode button can be a physical floating mode button, or a switch state of a virtual button on a PAD or mobile phone, or a voice command, etc. If the driver issues a floating mode switch request instruction, execute step S02; if the driver does not issue a floating mode switch request instruction, return to S00 for the next cycle, and continue to monitor whether the driver has input a floating mode switch request instruction;

[0050] S02: If the vehicle is in good condition and has no abnormality, no other functions mutually exclusive with the floating function are activated, and the floating mode has no faults, then execute step S03; otherwise, execute step S07, and output a message prompt of mode switching failure through the PAD or instrument;

[0051] S03: Determine whether the conditions for entering the floating mode meet the preset conditions, such as whether the vehicle speed is less than a threshold, whether the synchronization lock is in an unlocked state, etc. For a vehicle system including an engine component, if the above conditions are met, then execute step S04; otherwise, execute step S07, and output a message prompt of mode switching failure through the PAD or instrument. For a vehicle system not including an engine component, if the above preset conditions are met, then execute steps S05 and S06.

[0052] S04: For vehicles with engines, the floating mode will output an engine forced start request, a carbon canister solenoid valve and a DMTL solenoid valve circuit closing request before activation, so that the engine system is in normal working condition in advance to prevent water from entering the engine-related parts and causing engine damage.

[0053] S05: Floating mode activated, entering floating mode successfully.

[0054] S06: Through the PAD or instrument, the information prompt of successful mode switching is output.

[0055] Next, refer to Figure 2 When the vehicle meets the preset conditions, the vehicle is controlled to enter the wading state sub-mode first, and the wading driving control strategy is used to control the vehicle's driving. When the wading driving control strategy is used to control the vehicle's driving, it can be implemented in a variety of ways. For example, the torque average distribution method can be used to distribute the driving torque to each wheel of the vehicle. That is, when it is determined that the vehicle meets the preset conditions, the vehicle can be controlled to enter the wading state sub-mode first, and the torque average distribution method can be used to distribute the driving torque to each wheel of the vehicle.

[0056] Next, refer to Figure 2 , determine whether the vehicle is in a floating state. At this time, the vehicle is already in the wading state sub-mode, that is, after the vehicle switches to the wading state sub-mode, it is determined whether the vehicle is in a floating state. In the actual driving process of the vehicle, the wading depth value of the vehicle's wheels gradually increases from a normal state without water or with little water to a floating state. Therefore, in the embodiment of the present application, after receiving a request to enter the wading mode and determining that the vehicle meets the preset conditions for entering the wading mode, the vehicle is first switched to the wading state sub-mode of the wading mode. Although the wheels have waded at this time, they have not yet reached a state where the vehicle can float. The vehicle state at this time is defined as a wading state. And when the vehicle is in the wading state sub-mode, the state of the vehicle will continue to be monitored to determine whether the vehicle is in a floating state.

[0057] There are many ways to determine whether the vehicle is in a floating state. Several determination methods are exemplarily introduced below.

[0058] Exemplarily, when judging whether the vehicle is in a floating state, it can be judged based on the wading depth of each wheel of the vehicle, the slip state and the load state of each wheel suspension. By comprehensively judging whether the vehicle is in a floating state through multiple indicators such as the wading depth of the wheels, the slip state and the suspension load state, it can reduce the risk of misidentification brought by a single judgment method and improve the accuracy of judging whether the vehicle is in a floating state.

[0059] There are many ways to determine whether the vehicle is in a floating state, based on the wading depth, slip state and load state of each wheel of the vehicle. One method is described as follows.

[0060] For example, it is possible to determine whether the vehicle is in a floating state based on the wading depth of each wheel of the vehicle, the slipping state, and the load state of the suspension of each wheel, including: when the wading depth value of each wheel of the vehicle is greater than the vehicle floating threshold, the suspension of each wheel is in an unloaded state, and each wheel is in a slipping state, the vehicle is determined to be in a floating state. This improves the accuracy of determining whether the vehicle is in a floating state.

[0061] Exemplarily, when judging whether the vehicle is in a floating state according to the wading depth, slip state and suspension load state of each wheel of the vehicle, the wading depth value of each wheel of the vehicle can be obtained first, and it can be judged whether the wading depth value of each wheel is greater than the vehicle floating threshold. Then, when the wading depth value of each wheel is greater than the vehicle floating threshold, the suspension height value of each wheel is obtained. Then, according to the suspension height value of each wheel, it is judged whether the suspension of each wheel is in an unloaded state. Then, when the suspension of each wheel is in an unloaded state, it is obtained whether each wheel is in a slipping state. Then, when each wheel is in a slipping state, it is judged that the vehicle is in a floating state. It should be understood that the above is only an exemplary way of judging whether the vehicle is in a floating state according to multiple indicators such as wading depth, slip state and suspension load state. In addition, other judgment methods can also be used.

[0062] Combine the following Figure 3 and Figure 6 , an exemplary introduction to a specific vehicle floating state judgment process is given, and the specific steps are as follows:

[0063] S05030: Start.

[0064] S05031: Acquire status information such as water depth signal of the vehicle's wading sensor, suspension height signal of each wheel, vehicle speed and wheel speed signal of each wheel;

[0065] S05032: Calculate the wading depth value of each wheel according to the water depth signal of the wading sensor, and calculate the slip state of each vehicle according to the vehicle speed and the wheel speed of each wheel.

[0066] Among them, the wading sensor is used to detect the actual wading depth of the vehicle. Its specific form can be a contact sensor, and the contact sensor can be a liquid level depth detection sensor such as a float type, a capacitive type, etc. The wading sensor can also be a non-contact sensor, and the non-contact sensor can be a sensor such as an ultrasonic type, a laser type, a radar type, etc. The contact sensor can directly sense the liquid and measure more accurately, but because it needs to be in full contact with the liquid before it can be measured, there is a minimum detection depth limit. The non-contact sensor can detect the water surface height without hydraulic contact, and there is no minimum detection depth limit. This embodiment is illustrated by two non-contact water depth sensors arranged on the left rearview mirror and the right rearview mirror of the vehicle body.

[0067] Exemplary, reference Figure 6 , define the wheel center A of each wheel as the reference point of the wheel’s height above the water, and define the distance h from the wheel center A to the water surface as the wheel’s height above the water. A positive value indicates that it is above the water surface, and a negative value indicates that it is below the water surface. The wheel’s height above the water can be calculated using the following formula:

[0068] h iL =S L -P iL_z cos(α)cos(β)-P iL_x sin(α)cos(β)+P iL_y tan(β) (i=F / R)

[0069] h iR =S R -P iR_z cos(α)cos(β)-P iR_x sin(α)cos(β)+P iR_y tan(β) (i=F / R)

[0070] Among them, h iL (i=F / R) are the height of the left front wheel from the water and the height of the left rear wheel from the water respectively;

[0071] h iR (i=F / R) are the height of the right front wheel from the water and the height of the right rear wheel from the water respectively;

[0072] S L is the detection value of the left wading sensor, S R It is the detection value of the right wading sensor;

[0073] α is the body pitch angle_rad, β is the body roll angle_rad;

[0074] P iL_z(i=F / R) are the Z-direction distance from the left front wheel reference point to the left wading sensor installation point and the Z-direction distance from the left rear wheel reference point to the left wading sensor installation point respectively;

[0075] P iR_z (i=F / R) are the Z-direction distance from the right front wheel reference point to the right wading sensor installation point and the Z-direction distance from the right rear wheel reference point to the right wading sensor installation point respectively;

[0076] P iL_x (i=F / R) are the X-direction distance from the left front wheel reference point to the left wading sensor installation point and the X-direction distance from the left rear wheel reference point to the left wading sensor installation point respectively;

[0077] P iR_x (i=F / R) are the X-direction distance from the right front wheel reference point to the right wading sensor installation point and the X-direction distance from the right rear wheel reference point to the right wading sensor installation point respectively;

[0078] P iL_Y (i=F / R) is the Y-direction distance from the left front wheel reference point to the left wading sensor installation point, and the Y-direction distance from the left rear wheel reference point to the left wading sensor installation point;

[0079] P iR_Y (i=F / R) is the Y-direction distance from the right front wheel reference point to the right wading sensor installation point, and the Y-direction distance from the right rear wheel reference point to the left wading sensor installation point.

[0080] S05033: Obtain the wading depth value of each wheel, and determine whether the wading depth value of each wheel is greater than the vehicle floating threshold? If yes, execute step S05034; if no, execute step S05031;

[0081] S05034: Obtain the suspension height value of each wheel and determine whether the suspension of each wheel is in an unloaded state. If yes, execute step S05035; if no, execute step S05031;

[0082] Specifically, according to the difference between the suspension height of each wheel and the suspension height when the vehicle is floating in water and the suspension is unloaded, it is judged and output whether the suspension of each wheel is in an unloaded state:

[0083] Exemplarily, when judging and outputting whether the suspension of each wheel is in an unloaded state based on the difference between the suspension height of each wheel and the suspension height when the vehicle is floating in water and the suspension is unloaded,

[0084] The difference between the suspension height of each wheel and the suspension height when the vehicle is floating in water and the suspension is unloaded = |suspension height of each wheel - suspension height when the suspension is unloaded|;

[0085] If the difference between the suspension height of the wheel and the suspension height when the vehicle is floating in water and the suspension is unloaded is less than a threshold value (such as 5 mm), it is considered that the suspension of the wheel is in an unloaded state.

[0086] S05035: Obtain the slip state of each wheel and determine whether each wheel is in a slip state. If yes, execute step S05036; if no, execute step S05031;

[0087] For example, when calculating the slip state of each vehicle according to the vehicle speed and the wheel speed of each wheel, the slip state of each wheel is determined and output according to the difference between the wheel speed of each wheel and the vehicle speed:

[0088] The difference between the wheel speed of each wheel and the vehicle speed = |wheel speed of each wheel - vehicle speed|

[0089] If the difference between the wheel speed and the vehicle speed of each vehicle is greater than the slip threshold (such as 10 km / h), the wheel is considered to be in a slipping state.

[0090] S05036: Determine that the vehicle is in a floating state.

[0091] Next, refer to Figure 2 When the vehicle is in a floating state, the vehicle is controlled to switch from a wading state sub-mode to a floating state sub-mode, and a floating driving control strategy is used to control the vehicle's driving. Through the floating mode of the floatable vehicle, the wading state sub-mode and the floating state sub-mode are further divided according to whether the vehicle is in a floating state; when the vehicle meets the preset conditions and is in a floating state, the vehicle is controlled to switch from the wading state sub-mode to the floating state sub-mode, and the floating driving control strategy is used to control the vehicle's driving. Compared with the existing method of only setting the wading mode, the present application further divides the wading state sub-mode and the floating state sub-mode according to whether the vehicle is in a floating state, and respectively uses the wading driving control strategy and the floating driving control strategy to control the vehicle's driving, so that the vehicle's floating state and the wading state are well compatible and distinguished, so as to adapt to the scene changes of different wading degrees, so that the vehicle has a good ability to drive in water, and fills the gap of the drive control strategy of the prior art. In addition, the above method does not need to add an additional power system, but only needs to adopt different drive control strategies, without increasing costs, which is conducive to the promotion and application of floatable vehicles.

[0092] When the vehicle enters the floating state sub-mode, a variety of methods can be used to control the vehicle's driving using the floating driving control strategy. It should be noted that the floating driving control strategy and the wading driving control strategy are two different control strategies. The wading driving control strategy is relatively better adapted to vehicle driving in shallow water scenes, while the floating driving control strategy is relatively better adapted to vehicle driving in deep water scenes where the vehicle is in a floating state. The control method of the floating driving control strategy is described in detail below.

[0093] When the vehicle is in a floating state, the pre-control torque and torque correction of each wheel of the vehicle are determined by using a motion control algorithm according to the target yaw rate and actual yaw rate of the vehicle, as well as the pre-control target wheel speed and actual wheel speed of each wheel of the vehicle. The specific implementation method can adopt a variety of implementation methods. For example,

[0094] Exemplarily, when a motion control algorithm is used to determine the pre-controlled torque and torque correction of each wheel of the vehicle based on the target yaw angular velocity and actual yaw angular velocity of the vehicle, as well as the pre-controlled target wheel speed and actual wheel speed of each wheel of the vehicle, a first motion control algorithm can be used to first determine the target wheel speed correction of each wheel of the vehicle based on the target yaw angular velocity and actual yaw angular velocity of the vehicle; and then a second motion control algorithm can be used to determine the pre-controlled torque and torque correction of each wheel of the vehicle based on the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle.

[0095] There are many implementation methods for sequentially determining the target wheel speed correction amount, pre-control torque and torque correction amount of each wheel of the vehicle by using different motion control methods, which are also related to the current driving state of the vehicle.

[0096] In deep water scenarios, vehicles in a floating state can be divided into non-in-situ steering and in-situ steering. Among them, non-in-situ steering can specifically include straight driving, slow turning or deviation correction during straight driving, etc. Figure 5 In some embodiments, the present application also makes full use of the characteristics of independent four-wheel drive electric vehicles that have fast control feedback and can be independently controlled, and proposes different floating driving control strategies for non-in-situ steering driving and in-situ steering driving. The following is an exemplary introduction.

[0097] Exemplarily, the floating state sub-mode may include at least a floating travel control state. When the vehicle is in the floating state sub-mode and is not turning on the spot, the vehicle is in the floating travel control state.

[0098] Exemplarily, when the vehicle is in a floating state and is not turning in place, at this time, when the first motion control algorithm is used to determine the target wheel speed correction amount of each wheel of the vehicle according to the target yaw rate and the actual yaw rate of the vehicle, the following steps can be used: first, according to the steering wheel angle and the vehicle speed of the vehicle, based on the preset steering wheel angle-vehicle speed-target yaw rate relationship, the target yaw rate of the vehicle is determined. Then, according to the target yaw rate and the actual yaw rate of the vehicle, the first motion control algorithm is used to determine the target wheel speed correction amount of each wheel of the vehicle. The above-mentioned first motion control algorithm can be a PI, PD or PID control algorithm, which can be specifically implemented by a corresponding controller.

[0099] Exemplarily, when the vehicle is in a floating state and is not turning in place, at this time, when the second motion control algorithm is used to determine the pre-controlled torque and torque correction of each wheel of the vehicle based on the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle, the following method can be used. First, according to the throttle of the vehicle, based on the preset throttle-target wheel speed-motor pre-control torque relationship, the pre-controlled target wheel speed and pre-controlled torque of each wheel of the vehicle are determined; then, according to the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle, the second motion control algorithm is used to determine the torque correction of each wheel of the vehicle. The above-mentioned second motion control algorithm can be a PI, PD or PID control algorithm, which can be specifically implemented by a corresponding controller. The following is combined with the attached Figure 7 An implementation method is introduced by way of specific example.

[0100] Exemplarily, in the floating driving control state, refer to Figure 7 The floating driving control strategy can be: according to the throttle-target wheel speed-motor pre-control torque curve, the steering wheel angle-vehicle speed-target yaw rate curve, the PI, PD or PID control algorithm is used to determine the driving torque input to each wheel.

[0101] For example, when the driving torque input to each wheel is determined by using a PI, PD or PID control algorithm according to the throttle-target wheel speed-motor pre-control torque curve and the steering wheel angle-vehicle speed-target yaw rate curve, the reference Figure 7 The control structure block diagram of the control module in the floating driving control strategy shown;

[0102] in, Figure 7 2 in the figure represents the throttle-target wheel speed-motor pre-control torque curve, which can be calibrated through experimental tests. According to the throttle-target wheel speed-motor pre-control torque curve, the motor torque and motor stable speed range required for the vehicle to drive steadily in a straight line at different throttle openings in a floating state can be obtained.

[0103] Figure 7 11 in the figure represents a steering wheel angle-vehicle speed-target yaw rate curve. The steering wheel angle-vehicle speed-target yaw rate curve can be defined by the following mathematical relationship:

[0104]

[0105] Where δ = δ w / i steer , δ represents the front wheel steering angle deg, δ w Indicates the steering wheel angle deg, i steer Indicates the steering gear ratio. δ0 indicates the steering wheel angle threshold, which can be 5 to 10 degrees and is a calibrable quantity. u indicates the floating vehicle speed in km / h; K indicates the steering coefficient, which can be calibrated.

[0106] When determining the driving torque input to each wheel using PI, PD or PID control algorithms based on the throttle-target wheel speed-motor pre-control torque curve, steering wheel angle-vehicle speed-target yaw rate curve, refer to Figure 7First, according to the throttle size 1, the throttle-target wheel speed-motor pre-control torque curve 2 is looked up to obtain the pre-control target wheel speed 3 and the motor pre-control torque 4 required under the throttle opening; at the same time, according to the steering wheel angle size 10 and the floating vehicle speed 11, the steering wheel angle-vehicle speed-target yaw rate curve 12 is looked up to obtain the target yaw rate 13 required for steering under the current steering wheel angle and vehicle speed conditions. The target yaw rate and the actual yaw rate 17 are subtracted through the adder 14 to obtain the yaw rate response deviation. Then, the yaw rate response deviation is input to the input end of the 15 controller 1 as the input signal of the 15 controller 1. The 15 controller 1 here can be a PI controller, a PD controller, or a PID controller. The output signal of the 15 controller 1 is used as the target wheel speed correction amount, and is summed with the pre-control target wheel speed 3 through the adder 16 to obtain the target wheel speed. The target wheel speed and the actual wheel speed 18 are subtracted through the adder 5 to obtain the wheel speed response deviation. The response deviation of the wheel speed is input to the input end of the 6 controller 2 as the input signal of the 6 controller 2. The 6 controller 2 here can be a PI controller, a PD controller, or a PID controller. The output signal of the 6 controller 2 is used as the target torque correction amount, and is summed with the pre-control torque 4 through the adder 7 to obtain the target torque 8 of each wheel motor. After the vehicle and the motor controller receive the motor target torque signal, the motor torque control is performed. The actual wheel speed 18 of each wheel can be obtained by detecting the wheel speed sensor. The actual yaw rate 17 of the whole vehicle can be obtained by detecting the yaw rate sensor or the IMU sensor. In this way, a dual closed-loop control scheme based on the wheel speed closed loop and the yaw rate closed loop forms a complete dual closed-loop control loop composed of wheel speed and yaw rate, and composed of feedforward control formed by pre-control torque / wheel speed and controller feedback control, which has good control accuracy and control response characteristics.

[0107] In some embodiments of the present application, reference Figure 5 , and for on-the-spot turning driving, it is further divided into on-the-spot turning in driver mode and on-the-spot turning in automatic mode. Among them, on-the-spot turning in driver mode means that the driver drives the vehicle to turn on the spot by directly controlling the steering wheel and throttle operation. On-the-spot turning in automatic mode means that the driver only needs to input the steering direction and target steering angle, and the automatic driving system automatically controls the vehicle to turn on the spot. And this application also proposes different floating driving control strategies for on-the-spot turning in driver mode and on-the-spot turning in automatic mode. The following is an exemplary introduction.

[0108] When the vehicle is in a floating state and turning on the spot in the driver mode, the above-mentioned different motion control methods are used to determine the target wheel speed correction amount, pre-control torque and torque correction amount of each wheel of the vehicle in turn. The following method can be used.

[0109] Exemplarily, when the vehicle is in a floating state and is turning in place in the driver mode, when the first motion control algorithm is used to determine the target wheel speed correction amount of each wheel of the vehicle according to the target yaw rate and the actual yaw rate of the vehicle, the following method can be used: first, according to the throttle of the vehicle and the initial target yaw rate, based on the preset throttle-yaw rate increment relationship, the current target yaw rate of the vehicle is determined; then, according to the current target yaw rate and the actual yaw rate of the vehicle, the first motion control algorithm is used to determine the target wheel speed correction amount of each wheel of the vehicle. The above-mentioned first motion control algorithm can be a PI, PD or PID control algorithm, which can be specifically implemented by a corresponding controller.

[0110] Exemplarily, when the vehicle is in a floating state and turning on the spot in the driver mode, when the second motion control algorithm is used to determine the pre-control torque and torque correction of each wheel of the vehicle according to the pre-control target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle, the pre-control target wheel speed and pre-control torque of each wheel of the vehicle can be determined based on the target yaw rate of the vehicle and the preset target yaw rate-target wheel speed-motor pre-control torque relationship; then, the second motion control algorithm is used to determine the torque correction of each wheel of the vehicle according to the pre-control target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle. The above-mentioned second motion control algorithm can be a PI, PD or PID control algorithm, which can be implemented by a corresponding controller. Figure 8 An implementation method is introduced by way of specific example.

[0111] Exemplarily, the floating state sub-mode may also include at least a floating in-place steering control state of the driver mode, and when a request to enter the floating in-place steering control state of the driver mode is received, the vehicle is switched to the floating in-place steering control state of the driver mode. Figure 8 The floating driving control strategy can be: receiving the input throttle amount and steering wheel angle, and according to the throttle-yaw rate increment curve, the target yaw rate-target wheel speed-motor pre-control torque curve, using PI, PD or PID control algorithm, determine the driving torque input to each wheel.

[0112] For example, when receiving the input throttle amount and steering wheel angle amount, and determining the driving torque input to each wheel using PI, PD or PID control algorithm according to the throttle-yaw rate increment curve, the target yaw rate-target wheel speed-motor pre-control torque curve, the following method can be used: Figure 8 The control structure block diagram shown. Among them, Figure 83 in the figure represents the throttle-yaw rate increment curve, which can be calibrated through experimental tests. According to this set of curves, the target rotation rate increment that can be achieved by different throttle openings of the vehicle in the floating state can be obtained. Figure 8 5 in the figure is the target yaw rate-target wheel speed-motor pre-control torque curve, which can be calibrated through experimental tests. Based on this set of curves, the required motor torque and the motor stable speed range can be obtained when the vehicle rotates uniformly at different rotation speeds in a floating state.

[0113] When determining the driving torque input to each wheel using PI, PD or PID control algorithm based on the throttle-yaw rate increment curve, target yaw rate-target wheel speed-motor pre-control torque curve, refer to Figure 8 First, according to the throttle size 2, the throttle-yaw rate increment curve 3 is looked up to obtain the yaw rate increment under the throttle opening, and the yaw rate increment is summed with the initial target yaw rate 1 through an adder 14 to obtain the total target yaw rate. The purpose of setting the initial target yaw rate 1 is to achieve an initial default rotation speed of the vehicle when the driver does not step on the accelerator.

[0114] According to the total target yaw rate, the target yaw rate-target wheel speed-motor pre-control torque curve 5 is looked up in the table to obtain the required pre-control target wheel speed 6 and motor pre-control torque 8 under the target yaw rate. At the same time, the total target yaw rate and the actual yaw rate 15 are subtracted by the adder 13 to obtain the yaw rate response deviation. Then, the yaw rate response deviation is input to the input end of the controller 3 14 as the input signal of the controller 3 14. The controller 3 14 here can be a PI controller, a PD controller, or a PID controller.

[0115] The output signal of the 14 controller 3 is used as the target wheel speed correction amount, and is summed with the pre-controlled target wheel speed 6 through an adder 16 to obtain the target wheel speed. The target wheel speed and the actual wheel speed 18 are subtracted by an adder 7 to obtain the response deviation of the wheel speed. The response deviation of the wheel speed is input to the input end of the 9 controller 4 as the input signal of the 9 controller 4. The 9 controller 4 here can be a PI controller, a PD controller, or a PID controller. The output signal of the 9 controller 4 is used as the target torque correction amount, and is summed with the pre-controlled torque 8 through an adder 10 to obtain the target torque 11 of each wheel motor. After receiving the motor target torque signal, the whole vehicle and the motor controller perform motor torque control. The actual wheel speed 18 of each wheel can be detected and obtained by the wheel speed sensor. The actual yaw angular velocity 15 of the whole vehicle can be detected and obtained by the yaw rate sensor or the IMU sensor. In this way, a dual closed-loop control scheme based on wheel speed closed loop and yaw angular velocity closed loop forms a complete dual closed-loop control loop composed of wheel speed and yaw angular velocity, feedforward control formed by pre-controlled torque / wheel speed and controller feedback control, which has good control accuracy and control response characteristics.

[0116] Exemplarily, the floating state sub-mode may also include at least a floating in-situ steering control state in an automatic mode, and upon receiving a request to enter the floating in-situ steering control state in an automatic mode, the vehicle is switched to the floating in-situ steering control state in an automatic mode. When the vehicle is in a floating state and is steering in-situ in an automatic mode, the above-mentioned different motion control methods are respectively used to sequentially determine the target wheel speed correction amount, pre-control torque and torque correction amount of each wheel of the vehicle, and the following method can be used.

[0117] Exemplarily, when the vehicle is in a floating state and is turning in place in the automatic mode, at this time, when the pre-control torque and torque correction amount of each wheel of the vehicle are determined by using a motion control algorithm according to the target yaw rate and actual yaw rate of the vehicle, and the pre-control target wheel speed and actual wheel speed of each wheel of the vehicle, the target wheel speed correction amount of each wheel of the vehicle can be determined directly by using a first motion control algorithm according to the target yaw rate and actual yaw rate of the vehicle. The above-mentioned first motion control algorithm can be a PI, PD or PID control algorithm, which can be specifically implemented by a corresponding controller.

[0118] Exemplarily, when the vehicle is in a floating state and is turning in place in the automatic mode, at this time, when the first motion control algorithm is used to determine the target wheel speed correction amount of each wheel of the vehicle according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle, the following method can be used: according to the target yaw angular velocity, the actual yaw angular velocity and the target rotation angle of the vehicle, the first motion control algorithm is used to determine the target wheel speed correction amount of each wheel of the vehicle. The target rotation angle is a target rotation angle parameter input in the automatic mode, which can be left turn or right turn, which is specifically reflected in the target rotation angle.

[0119] Exemplarily, when the vehicle is in a floating state and turning on the spot in automatic mode, at this time, according to the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle, a second motion control algorithm is used to determine the pre-controlled torque and torque correction of each wheel of the vehicle. The following steps can be used. First, according to the target yaw rate of the vehicle, based on the preset target yaw rate-target wheel speed-motor pre-control torque relationship, the pre-controlled target wheel speed and pre-controlled torque of each wheel of the vehicle are determined. Thereafter, according to the pre-controlled target wheel speed, actual wheel speed and target wheel speed correction of each wheel of the vehicle, a second motion control algorithm is used to determine the torque correction of each wheel of the vehicle. The above-mentioned second motion control algorithm can be a PI, PD or PID control algorithm, which can be specifically implemented by a corresponding controller. The following is combined with the attached Fig. 9 An implementation method is introduced by way of specific example.

[0120] In the automatic mode of floating on-the-spot steering control, refer to Fig. 9 The floating driving control strategy can be: receiving the input vehicle target steering direction and target rotation angle, and according to the preset target yaw rate, target vehicle speed, and target yaw rate-target wheel speed-motor pre-control torque curve, using PI, PD or PID control algorithm to determine the driving torque input to each wheel.

[0121] When receiving the input vehicle target steering direction and target rotation angle, according to the preset target yaw rate, target vehicle speed, and target yaw rate-target wheel speed-motor pre-control torque curve, the PI, PD or PID control algorithm is used to determine the driving torque input to each wheel. Fig. 9 The control structure block diagram is shown.

[0122] In the automatic mode of floating in-situ steering control, the vehicle's control target is to turn the vehicle to the target rotation angle received at the preset rotation angular velocity. When the actual rotation angular velocity deviates greatly from the preset rotation angular velocity, a speed control method based on the rotation angular velocity closed loop is used for correction control; when the actual rotation angular velocity is close to the target rotation angular velocity, a position control method based on the rotation angular velocity closed loop is used for correction control.

[0123] Specifically, when the driving torque input to each wheel is determined by using PI, PD or PID control algorithm according to the preset target yaw rate, target vehicle speed, and target yaw rate-target wheel speed-motor pre-control torque curve, first, according to the preset target yaw rate 1, the target yaw rate-target wheel speed-motor pre-control torque curve 3 is looked up in the table to obtain the pre-controlled target wheel speed 5 and motor pre-control torque 10 required at the rotation speed.

[0124] On the one hand, the target yaw rate and the actual yaw rate 18 are subtracted by the adder 2 to obtain the yaw rate response deviation. Then, the yaw rate response deviation is input to the input end of the 4 controller 5 as the input signal of the 4 controller 5. The 4 controller 5 here can be a PI controller, a PD controller or a PID controller.

[0125] On the other hand, the actual yaw rate 18 is used to obtain the actual yaw angle through the integrator 17. The target rotation angle 14 and the actual yaw angle are subtracted through the adder 15 to obtain the response deviation of the yaw angle. Then, the response deviation of the yaw angle is input to the input end of the 16 controller 7 as the input signal of the 16 controller 7. The 16 controller 7 here can be a PI controller, a PD controller, or a PID controller.

[0126] The response deviation of the yaw angle, the output end of the controller 5, and the output end of the controller 7 obtained by the adder 15 are input to the comparison selector 6 respectively. When the response deviation of the yaw angle is greater than the threshold value, the target wheel speed correction amount = the output result of the controller 5; otherwise, the target wheel speed correction amount = the output result of the controller 7. In this way, the switching of the two control algorithms of the controller 5 and the controller 7 is realized.

[0127] The target wheel speed correction amount and the pre-controlled target wheel speed 5 are summed by an adder 7 to obtain the target wheel speed. The target wheel speed and the actual wheel speed 19 are subtracted by an adder 8 to obtain the response deviation of the wheel speed. The response deviation of the wheel speed is input to the input end of the 9 controller 6 as the input signal of the 9 controller 6. The 9 controller 6 here can be a PI controller, a PD controller, or a PID controller.

[0128] The output signal of the controller 6 is used as the target torque correction amount, and is summed with the pre-control torque 10 through the adder 11 to obtain the target torque 12 of each wheel motor. After receiving the motor target torque signal, the vehicle and the motor controller perform motor torque control. The actual wheel speed 19 of each wheel can be obtained by detecting the wheel speed sensor. The actual yaw rate 18 of the vehicle can be detected by the yaw rate sensor or the IMU sensor. In this way, the dual closed-loop control scheme based on the wheel speed closed loop and the yaw rate closed loop forms a complete dual closed-loop control loop composed of wheel speed and yaw rate, and composed of feedforward control formed by pre-control torque / wheel speed and controller feedback control, which has good control accuracy and control response characteristics.

[0129] Exemplarily, the driving control method may further include: detecting whether a floating function of the vehicle has a floating failure; when the floating function of the vehicle is detected to have a floating failure and the vehicle is in a floating state, using a wading driving control strategy to control the vehicle's driving. In a more preferred embodiment, when the vehicle is in a floating state, it is also possible to detect whether a floating function of the vehicle has a floating failure. Figure 5 When a floating failure is detected in the vehicle's floating function, the vehicle is controlled to switch from the floating state sub-mode to the wading state sub-mode.

[0130] Combine the following Figure 4 and Figure 5 , a control flow chart of mutual switching between different sub-modes in floating mode is introduced by way of example, and the specific steps are as follows.

[0131] S0500: Indicates that the floating mode is activated and the floating mode is successfully entered.

[0132] S0501: After entering the floating mode, the vehicle will first be placed in the wading state sub-mode. At this time, if the vehicle state does not effectively jump to the floating state sub-mode, the vehicle will execute step S0502 to execute the wading driving control strategy in the wading state sub-mode. Under this wading driving control strategy, the torque of each wheel adopts the torque average distribution method, and there is no differential control effect.

[0133] S0503: Execute the vehicle floating judgment control program. If yes, execute step S0504; if no, maintain the wading state sub-mode and continue to execute step S0502, adopting the wading driving control strategy;

[0134] S0504: The vehicle will be placed in the floating state sub-mode;

[0135] S0505: Detect whether the vehicle's floating function fails in the floating state. If yes, return to S0501, re-enter the wading state sub-mode, and adopt the wading driving control strategy to achieve function degradation and emergency driving in the floating function failure state. If no, execute step S0506.

[0136] S0506: Perform general water-floating driving control. The vehicle will execute step S0507 to execute the water-floating driving control strategy under the water-floating driving control state.

[0137] S0508: Determine whether the driver further selects and issues a floating on-the-spot steering-automatic mode request in the floating driving state. If yes, execute S0509; if not, maintain the floating driving state.

[0138] S0509: The vehicle will be in the automatic mode of floating on-the-spot steering control.

[0139] S0510: In this state, the vehicle will adopt the floating driving control strategy in the automatic mode of floating on-the-spot steering control state.

[0140] In the automatic mode of floating on-the-spot steering control, the driver can select the vehicle's turning direction and target turning angle. The vehicle will rotate at a constant speed in the driver's selected turning direction according to the default yaw rate (such as 20deg / s, the value can be calibrated) until the target turning angle is reached and the vehicle stops automatically.

[0141] S0511: Determine whether the driver further selects and issues a floating on-the-spot steering-driver mode request in the floating driving state. If yes, execute S0512; if not, maintain the floating driving state.

[0142] S0512: The vehicle will be in the floating on-the-spot steering control state of the driver mode.

[0143] S0513: In this state, the vehicle will adopt the floating driving control strategy in the floating on-the-spot steering control state of the driver mode.

[0144] In the floating steering control state of the driver mode, the driver can choose the direction of the vehicle's rotation by turning the steering wheel or the direction selection button. The vehicle's rotation speed can be controlled by the accelerator. The rotation can be stopped by stepping on the brake.

[0145] In the various embodiments shown above, for a vehicle driven by four motors independently, when it is detected that the vehicle is in a floating state, a motion control algorithm is used to determine the pre-control torque and torque correction of each wheel of the vehicle according to the target yaw rate and actual yaw rate of the vehicle, as well as the pre-control target wheel speed and actual wheel speed of each wheel of the vehicle; then, according to the pre-control torque and torque correction of each wheel of the vehicle, the target torque output of the motor corresponding to each wheel of the vehicle is determined to control the driving of the vehicle. The dual closed-loop control scheme based on the wheel speed closed loop and the yaw rate closed loop forms a complete dual closed-loop control loop composed of wheel speed and yaw rate, feedforward control formed by pre-control torque / wheel speed and controller feedback control, which has good control accuracy and control response characteristics.

[0146] Moreover, in other embodiments, the embodiment of the present application is directed to the floating mode of the floatable vehicle, and further divides the wading state sub-mode and the floating state sub-mode according to whether the vehicle is in a floating state; when the vehicle meets the preset conditions, the vehicle is controlled to enter the wading state sub-mode, and the wading driving control strategy is adopted to control the vehicle driving; when the vehicle is in the wading state sub-mode, it is also determined whether the vehicle is in a floating state, and when the vehicle is in a floating state, the vehicle is controlled to switch from the wading state sub-mode to the floating state sub-mode, and the floating driving control strategy is adopted to control the vehicle driving. Compared with the existing method of only setting the wading mode, the present application further divides the wading state sub-mode and the floating state sub-mode according to whether the vehicle is in a floating state, and respectively adopts the wading driving control strategy and the floating driving control strategy to control the vehicle driving, so that the vehicle floating state and the wading state are well compatible and distinguished, so as to adapt to the scene changes of different wading degrees, so that the vehicle has good water driving ability, and fills the gap of the driving control strategy of the prior art. In addition, the above method does not need to add an additional power system, but only needs to adopt different driving control strategies, without increasing costs, which is conducive to the promotion and application of floatable vehicles.

[0147] Secondly, an embodiment of the present application also provides a drive control device for a floatable vehicle, the drive control device comprising: a first calculation module and a second calculation module; wherein the first calculation module is used to: when the vehicle is in a floating state, use a motion control algorithm to determine the pre-control torque and torque correction amount of each wheel of the vehicle based on the target yaw angular velocity and actual yaw angular velocity of the vehicle, and the pre-control target wheel speed and actual wheel speed of each wheel of the vehicle; the second calculation module is used to: when the vehicle is in a floating state, use the pre-control torque and torque correction amount of each wheel of the vehicle to determine the target torque output by the motor corresponding to each wheel of the vehicle to control the vehicle's driving.

[0148] It should be explained that the first calculation module and the second calculation module are both functional modules combining software and hardware. The specific calculation method of each calculation module can refer to the corresponding description of the aforementioned method part, which will not be repeated here. It should also be noted that the drive control device is not limited to the functional modules shown above, and in addition, it can also include other functional modules to implement the corresponding steps of the aforementioned method part.

[0149] In addition, an embodiment of the present application also provides a drive control system for a floatable vehicle, which drive control system for a floatable vehicle includes: a storage medium and a processor, the storage medium stores a computer program run by the processor, and when the computer program is run by the processor, the processor executes any one of the above-mentioned drive control methods for a floatable vehicle.

[0150] Fig.10 FIG. 1 is a schematic block diagram of a driving control system 100 of a floatable vehicle according to an embodiment of the present application. Fig.10 As shown, the driving control system 100 of a floatable vehicle according to an embodiment of the present application may include a storage medium 110 and a processor 120. The storage medium 110 stores a computer program executed by the processor 120. When the computer program is executed by the processor 120, the processor 120 executes the driving control method of the floatable vehicle according to the embodiment of the present application described above.

[0151] The storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0152] Furthermore, the embodiment of the present application further provides a storage medium, on which a computer program is stored, and when the computer program is run, any of the above-mentioned drive control methods for a floatable vehicle is executed. The storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0153] In addition, an embodiment of the present application further provides a floatable vehicle, which includes: a vehicle body, and a drive control system of any of the above-mentioned floatable vehicles arranged on the vehicle body. Specifically, the floatable vehicle can be any type of vehicle that can float and travel in water, such as, but not limited to, a passenger car, a truck, etc. The above-mentioned vehicle body can include structures such as a frame, wheels, a gearbox, and a steering wheel. The floatable vehicle can be, for example, but not limited to, a vehicle that is driven by floating water only by wheels, the floatable vehicle can be a distributed drive vehicle, the floatable vehicle can have engine components, or can have no engine components, the floatable vehicle can be, for example, but not limited to, a pure electric vehicle, a fuel vehicle, a plug-in hybrid vehicle, and an extended-range hybrid vehicle.

[0154] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A driving control method for a floatable vehicle, wherein the vehicle is independently driven by four motors, characterized in that: include: When the vehicle is in a floating state, a motion control algorithm is used to determine a pre-controlled torque and a torque correction amount of each wheel of the vehicle according to a target yaw rate and an actual yaw rate of the vehicle, and a pre-controlled target wheel speed and an actual wheel speed of each wheel of the vehicle; According to the pre-control torque of each wheel of the vehicle and the torque correction amount, the target torque output by the motor corresponding to each wheel of the vehicle is determined to control the driving of the vehicle.

2. The driving control method according to claim 1, characterized in that: The method of determining the pre-control torque and torque correction amount of each wheel of the vehicle by using a motion control algorithm according to the target yaw rate and the actual yaw rate of the vehicle, and the pre-control target wheel speed and the actual wheel speed of each wheel of the vehicle comprises: Determine a target wheel speed correction amount for each wheel of the vehicle using a first motion control algorithm according to the target yaw rate and the actual yaw rate of the vehicle; According to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction of each wheel of the vehicle, a second motion control algorithm is adopted to determine the pre-controlled torque and the torque correction of each wheel of the vehicle.

3. The driving control method according to claim 2, characterized in that: When the vehicle is in the floating state and is not turning in situ, determining the target wheel speed correction amount of each wheel of the vehicle by using a first motion control algorithm according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle includes: Determining a target yaw rate of the vehicle according to a steering wheel angle and a vehicle speed of the vehicle and based on a preset steering wheel angle-vehicle speed-target yaw rate relationship; The first motion control algorithm is used to determine a target wheel speed correction amount for each wheel of the vehicle according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle.

4. The driving control method according to claim 3, characterized in that: The method of determining the pre-controlled torque and torque correction amount of each wheel of the vehicle by using a second motion control algorithm according to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction amount of each wheel of the vehicle comprises: According to the throttle of the vehicle, based on a preset throttle-target wheel speed-motor pre-control torque relationship, determining the pre-control target wheel speed and pre-control torque of each wheel of the vehicle; According to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction of each wheel of the vehicle, a second motion control algorithm is adopted to determine the torque correction of each wheel of the vehicle.

5. The driving control method according to claim 2, characterized in that: When the vehicle is in the floating state and is turning in situ in the driver mode, determining the target wheel speed correction amount of each wheel of the vehicle by using a first motion control algorithm according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle includes: Determining a current target yaw rate of the vehicle according to a throttle and an initial target yaw rate of the vehicle and based on a preset throttle-yaw rate increment relationship; The first motion control algorithm is used to determine a target wheel speed correction amount for each wheel of the vehicle according to the current target yaw rate and the actual yaw rate of the vehicle.

6. The driving control method according to claim 5, characterized in that: The method of determining the pre-controlled torque and torque correction amount of each wheel of the vehicle by using a second motion control algorithm according to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction amount of each wheel of the vehicle comprises: According to the target yaw rate of the vehicle, based on a preset target yaw rate-target wheel speed-motor pre-control torque relationship, determining a pre-control target wheel speed and a pre-control torque of each wheel of the vehicle; The torque correction amount of each wheel of the vehicle is determined by using the second motion control algorithm according to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction amount of each wheel of the vehicle.

7. The driving control method according to claim 2, characterized in that: When the vehicle is in the floating state and is turning in situ in the automatic mode, determining the target wheel speed correction amount of each wheel of the vehicle by using a first motion control algorithm according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle includes: The first motion control algorithm is used to determine a target wheel speed correction amount for each wheel of the vehicle according to the target yaw rate, the actual yaw rate and the target rotation angle of the vehicle.

8. The driving control method according to claim 7, characterized in that: The method of determining the pre-controlled torque and torque correction amount of each wheel of the vehicle by using a second motion control algorithm according to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction amount of each wheel of the vehicle comprises: According to the target yaw rate of the vehicle, based on a preset target yaw rate-target wheel speed-motor pre-control torque relationship, determining a pre-control target wheel speed and a pre-control torque of each wheel of the vehicle; The torque correction amount of each wheel of the vehicle is determined by using the second motion control algorithm according to the pre-controlled target wheel speed, the actual wheel speed and the target wheel speed correction amount of each wheel of the vehicle.

9. The drive control method according to any one of claims 1 to 8, characterized in that: Also includes: Whether the vehicle is in a floating state is determined according to the wading depth and slip state of each wheel of the vehicle and the load state of each wheel suspension.

10. The driving control method according to claim 9, characterized in that: The determining whether the vehicle is in a floating state according to the wading depth and the slip state of each wheel of the vehicle and the load state of the suspension of each wheel includes: When the wading depth value of each wheel of the vehicle is greater than the vehicle floating threshold, the suspension of each wheel is in an unloading state, and each wheel is in a slipping state, it is determined that the vehicle is in the floating state.

11. The driving control method according to claim 1, characterized in that: Also includes: When a request to enter a floating mode is received and the vehicle meets a preset condition, a wading driving control strategy is adopted to control the vehicle to travel; In the process of controlling the vehicle's travel by adopting the wading travel control strategy, it is determined whether the vehicle is in the floating state.

12. The driving control method according to claim 11, characterized in that: Also includes: Detecting whether a floating function of the vehicle has a floating failure; When it is detected that a floating function of the vehicle has a floating failure and the vehicle is in the floating state, the wading driving control strategy is used to control the driving of the vehicle.

13. The driving control method according to claim 11, characterized in that: The preset conditions at least include: The speed of the vehicle is less than a preset threshold; The synchronous lock of the vehicle is in an unlocked state; When the floatable vehicle has an engine, the engine is in a started state, and the circuits where the carbon canister solenoid valve and the DMTL solenoid valve of the vehicle are located are both in a closed state.

14. The driving control method according to claim 11, characterized in that: The method of controlling the vehicle driving by adopting a wading driving control strategy includes: The target torque output by the motor corresponding to each wheel of the vehicle is determined by using the torque average distribution method.

15. A driving control device for a floatable vehicle, characterized in that: include: a first calculation module, configured to determine a pre-controlled torque and a torque correction amount of each wheel of the vehicle by using a motion control algorithm according to a target yaw rate and an actual yaw rate of the vehicle, and a pre-controlled target wheel speed and an actual wheel speed of each wheel of the vehicle when the vehicle is in a floating state; The second calculation module is used to determine the target torque output by the motor corresponding to each wheel of the vehicle according to the pre-control torque and the torque correction amount of each wheel of the vehicle when the vehicle is in the floating state, so as to control the driving of the vehicle.

16. A driving control system for a floatable vehicle, characterized in that: include: A storage medium and a processor, wherein the storage medium stores a computer program to be executed by the processor, and when the computer program is executed by the processor, the processor executes the driving control method of the floatable vehicle according to any one of claims 1 to 15.

17. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is run, the drive control method of the floatable vehicle according to any one of claims 1 to 15 is executed.

18. A floatable vehicle, characterized in that: include: Vehicle body; A driving control system for a floatable vehicle according to claim 16, arranged on the vehicle body.

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