Drive system of a road roller and control method thereof, road roller

Abstract

The application relates to the technical field of working machines, in particular to a driving system of a road roller, a control method of the driving system and the road roller, wherein the method comprises the following steps: determining a target speed of the road roller; based on the target speed of the road roller, adjusting an actual speed of front wheels by controlling a displacement of a traveling pump and a displacement of a traveling motor; determining a target power of an electric driving system of rear wheels based on an actual power of a hydraulic driving system of the front wheels and a power distribution ratio of the hydraulic driving system of the front wheels and the electric driving system of the rear wheels; and based on the target speed of the road roller and the target power of the electric driving system of the rear wheels, adjusting the actual speed of the rear wheels and an actual power of the electric driving system by controlling a torque and a rotating speed output by a rear electric motor. Thus, the scheme of a double driving system including the hydraulic driving system of the front wheels and the electric driving system of the rear wheels is realized, the problems existing in the single driving system of the rear wheels are avoided, and the requirement of a steeper slope can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of working machines, in particular to a driving system of a road roller, a control method of the driving system and the road roller. BACKGROUND

[0002] The road roller is a road equipment which has been widely applied at present and can roll soil, asphalt concrete and other pavements. In order to ensure construction quality, the mass of the front wheel of many road rollers (for example, single steel wheel road roller) is larger than that of the rear wheel, for example, the mass ratio of the front wheel to the rear wheel is 17:9. For the rear wheel single drive system, the adhesion of the whole machine is not enough due to the small mass ratio of the rear wheel, which leads to insufficient maximum traction and cannot meet the requirements of steep slopes. SUMMARY

[0003] The present application provides a driving system of a road roller, a control method of the driving system and the road roller, which solves or improves the defects that the rear wheel single drive system of the road roller in the prior art cannot meet the requirements of steep slopes, and realizes the scheme of the double drive system based on the hydraulic drive system of the front wheel and the electric drive system of the rear wheel.

[0004] The present application provides a driving system control method of a road roller, comprising:

[0005] determining a target speed of the road roller; the driving system of the road roller comprises a hydraulic drive system of a front wheel and an electric drive system of a rear wheel, the hydraulic drive system of the front wheel comprises a travel motor and a travel pump, and the electric drive system of the rear wheel comprises a rear drive motor;

[0006] based on the target speed of the road roller, adjusting the actual speed of the front wheel by controlling the displacement of the travel pump and the displacement of the travel motor, and obtaining the actual power of the hydraulic drive system of the front wheel after adjustment;

[0007] based on the actual power of the hydraulic drive system of the front wheel and the power distribution ratio of the hydraulic drive system of the front wheel and the electric drive system of the rear wheel, determining the target power of the electric drive system of the rear wheel;

[0008] based on the target speed of the road roller and the target power of the electric drive system of the rear wheel, adjusting the actual speed of the rear wheel and the actual power of the electric drive system by controlling the torque and the rotating speed output by the rear drive motor.

[0009] According to the driving system control method of the road roller provided by the present application, the power distribution ratio is determined by the following way:

[0010] determining the ratio of the maximum adhesion corresponding to the front axle of the road roller to the maximum adhesion corresponding to the rear axle of the road roller as the power distribution ratio.

[0011] A driving system control method of a road roller is provided, which adjusts an actual speed of a front wheel based on a target speed of the road roller by controlling a displacement of a traveling pump and a displacement of a traveling motor, and includes:

[0012] A front-rear wheel speed difference is determined based on a steering angle, the front-rear wheel speed difference being used to represent a difference between the target speed of the front wheel and a target speed of a rear wheel;

[0013] The target speed of the front wheel is determined based on the target speed of the road roller and the front-rear wheel speed difference;

[0014] The actual speed of the front wheel is adjusted based on the target speed of the front wheel by controlling the displacement of the traveling pump and the displacement of the traveling motor.

[0015] A driving system control method of a road roller is provided, which adjusts an actual speed of a front wheel based on a target speed of the front wheel by controlling a displacement of a traveling pump and a displacement of a traveling motor, and includes:

[0016] If it is determined that the actual speed of the rear wheel is greater than the target speed of the road roller, the road roller is braked so that the actual speed of the rear wheel is less than or equal to the target speed of the road roller, and a speed adjustment step is performed;

[0017] If it is determined that the actual speed of the rear wheel is less than or equal to the target speed of the road roller, the speed adjustment step is performed;

[0018] The speed adjustment step includes:

[0019] A preset corresponding relationship is obtained, the corresponding relationship including a speed range corresponding to each gear of a plurality of gears of the displacement of the traveling motor;

[0020] The actual speed of the front wheel is adjusted based on the target speed of the front wheel and the corresponding relationship by controlling the displacement of the traveling pump and the displacement of the traveling motor.

[0021] A driving system control method of a road roller is provided, which adjusts an actual speed of a front wheel based on a target speed of the front wheel and a corresponding relationship by controlling a displacement of a traveling pump and a displacement of a traveling motor, and includes:

[0022] If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is greater than or equal to the target speed of the front wheel, a first target displacement of the traveling pump corresponding to the target speed of the front wheel is determined at the current gear of the displacement of the traveling motor, and the actual speed of the front wheel is adjusted by adjusting the displacement of the traveling pump to the first target displacement;

[0023] If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is less than the target speed of the front wheel, the current gear of the displacement of the traveling motor is gradually reduced, and when the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is greater than or equal to the target speed of the front wheel, the reduction of the current gear of the displacement of the traveling motor is stopped, and a first target displacement of the traveling pump corresponding to the target speed of the front wheel is determined at the current gear of the displacement of the traveling motor, and the actual speed of the front wheel is adjusted by adjusting the displacement of the traveling pump to the first target displacement.

[0024] According to the present application, a driving system control method of a road roller is provided, and after the actual speed of the front wheel is adjusted by adjusting the displacement of the traveling pump to the first target displacement, the method further comprises:

[0025] If the difference between the actual speed of the front wheel and the target speed of the front wheel is greater than or equal to a preset difference value, the target speed of the front wheel is corrected so that the difference between the actual speed of the front wheel and the target speed of the front wheel is less than the preset difference value.

[0026] According to the present application, a driving system control method of a road roller is provided, and the braking of the road roller comprises:

[0027] The electric braking condition of the road roller is obtained, the electric braking condition comprises a first condition and a second condition, the first condition comprises that the electric quantity of the power supply of the road roller is less than or equal to a preset electric quantity, and the second condition comprises that the required braking force of the road roller is less than or equal to a preset braking force;

[0028] If it is determined that the road roller satisfies the first condition and does not satisfy the second condition, the actual speed of the front wheel is reduced by controlling the displacement of the traveling pump and the displacement of the traveling motor based on the corresponding relationship, so that the road roller satisfies the electric braking condition;

[0029] If it is determined that the road roller satisfies the electric braking condition, the braking energy recovery of the rear-drive motor is controlled.

[0030] According to the method for controlling the driving system of the road roller provided in the application, the actual speed of the front wheels is reduced by controlling the displacement of the traveling pump and the displacement of the traveling motor based on the corresponding relationship, so that the road roller meets the electric braking condition, comprising:

[0031] If it is determined that the target speed of the front wheels is greater than the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the actual speed of the front wheels is reduced by reducing the displacement of the traveling pump under the current gear of the displacement of the traveling motor.

[0032] If it is determined that the target speed of the front wheels is less than or equal to the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the current gear of the displacement of the traveling motor is gradually increased, and when the target speed of the front wheels is greater than the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the increase of the current gear of the displacement of the traveling motor is stopped, and the actual speed of the front wheels is reduced by reducing the displacement of the traveling pump under the current gear of the displacement of the traveling motor.

[0033] The application further provides a driving system of a road roller for implementing any of the above-mentioned methods for controlling the driving system of the road roller, comprising a vehicle controller, a hydraulic driving system of front wheels and an electric driving system of rear wheels.

[0034] The hydraulic driving system of the front wheels comprises a traveling motor and a traveling pump.

[0035] The electric driving system of the rear wheels comprises a rear-drive motor.

[0036] The vehicle controller is in communication connection with the hydraulic driving system of the front wheels and the electric driving system of the rear wheels.

[0037] According to the driving system of the road roller provided in the application, the rear-drive motor is connected with the rear wheels through a speed reducer, and / or the traveling motor is connected with the front wheels through a speed reducer.

[0038] The driving system of the road roller provided in the application further comprises a multi-combination assembly, a vibration pump and an auxiliary pump for steering and braking.

[0039] The driving system of the road roller further comprises an integrated electric drive assembly connected with the vehicle controller, the all-in-one assembly is connected with the rear drive motor and the integrated electric drive assembly respectively, and the integrated electric drive assembly is connected with the traveling pump, the vibration pump and the auxiliary pump respectively; or, the driving system of the road roller further comprises a front drive motor and an integrated electric drive assembly connected with the vehicle controller, the all-in-one assembly is connected with the rear drive motor, the front drive motor and the integrated electric drive assembly respectively, the front drive motor is connected with the traveling pump and the vibration pump respectively, and the integrated electric drive assembly is connected with the auxiliary pump; or, the driving system of the road roller further comprises a front drive motor and an integrated electric drive assembly connected with the vehicle controller, the all-in-one assembly is connected with the rear drive motor, the front drive motor and the integrated electric drive assembly respectively, the front drive motor is connected with the traveling pump, and the integrated electric drive assembly is connected with the vibration pump and the auxiliary pump respectively.

[0040] The application further provides a driving system control device of a road roller, comprising:

[0041] a speed determination module configured to determine a target speed of the road roller, wherein the driving system of the road roller comprises a hydraulic driving system of front wheels and an electric driving system of rear wheels, the hydraulic driving system of the front wheels comprises a traveling motor and a traveling pump, and the electric driving system of the rear wheels comprises a rear drive motor;

[0042] a front wheel adjustment module configured to adjust an actual speed of the front wheels by controlling a displacement of the traveling pump and a displacement of the traveling motor based on the target speed of the road roller, and obtain an actual power of the hydraulic driving system of the front wheels after the adjustment;

[0043] a power distribution module configured to determine a target power of the electric driving system of the rear wheels based on the actual power of the hydraulic driving system of the front wheels and a power distribution ratio of the hydraulic driving system of the front wheels and the electric driving system of the rear wheels;

[0044] a rear wheel adjustment module configured to adjust an actual speed of the rear wheels and an actual power of the electric driving system of the rear wheels by controlling a torque and a rotating speed output by the rear drive motor based on the target speed of the road roller and the target power of the electric driving system of the rear wheels.

[0045] The application further provides an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the driving system control method of the road roller according to any one of the above-mentioned embodiments when executing the program.

[0046] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the driving system control method of the road roller.

[0047] The application further provides a road roller, which comprises a road roller body, and the road roller body is provided with the driving system of the road roller, the driving system control device of the road roller, the electronic device or the computer readable storage medium of the road roller according to any one of the above.

[0048] The driving system control method of the road roller provided by the application can drive the front wheels through the travel pump and the travel motor of the hydraulic driving system of the front wheels, drive the rear wheels through the rear-drive motor of the electric driving system of the rear wheels, realize the double driving system of the road roller, avoid the problems of the single driving system of the rear wheels, improve the adhesion of the whole machine, increase the traction, meet the requirements of steeper slopes, improve the construction quality, determine the target speed of the road roller, adjust the actual speed of the front wheels through the displacement of the travel pump and the displacement of the travel motor based on the target speed, obtain the target power of the electric driving system of the rear wheels based on the actual power of the hydraulic driving system of the front wheels and the power distribution ratio of the hydraulic driving system of the front wheels and the electric driving system of the rear wheels, and adjust the actual speed of the rear wheels and the actual power of the electric driving system through the torque and the rotating speed output by the rear-drive motor in combination with the target speed of the road roller, so as to realize the compound control of the hydraulic driving system of the front wheels and the electric driving system of the rear wheels. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0050] Figure 1 is one of the flowcharts of the driving system control method of the road roller provided by the application;

[0051] Figure 2 is one of the structural diagrams of the driving system of the road roller provided by the application;

[0052] Figure 3 is the second structural diagram of the driving system of the road roller provided by the application;

[0053] Figure 4Figure 3 is a schematic structural diagram of a third driving system of the road roller according to the present application;

[0054] Figure 5 Figure 2 is a schematic flow chart of a second driving system control method of the road roller according to the present application;

[0055] Figure 6 Figure 1 is a schematic structural diagram of a driving system control device of the road roller according to the present application;

[0056] Figure 7 Figure 4 is a schematic structural diagram of an electronic device according to the present application. DETAILED DESCRIPTION

[0057] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0058] The road roller is a road equipment that has been widely applied at present, and can roll and compact soil, asphalt concrete and the like. In order to ensure construction quality, the mass of the front wheel of many road rollers (for example, single steel wheel road roller) is larger, and the mass of the rear wheel is smaller, for example, the mass ratio of the front wheel to the rear wheel is 17:9. For the rear wheel single drive system, since the mass ratio of the rear wheel is small, the adhesion of the whole machine is not enough, which leads to insufficient maximum traction, and cannot meet the requirements of a relatively steep slope. When the adhesion is not enough, the rear wheel skids, which will cause wrinkles on the compacted road surface, and reduce the construction quality.

[0059] For example, the mechanical single drive scheme based on the engine, clutch and gearbox, and the hydraulic single drive scheme based on the engine, hydraulic pump and rear drive hydraulic motor, both have the problem of insufficient adhesion.

[0060] Although the full hydraulic double drive scheme based on the engine, hydraulic pump, front drive and rear drive hydraulic motor can be used in the prior art, the efficiency is not high. In addition, the full electric double drive scheme based on battery electric control in which the front drive and the rear drive are both electric machines can also be used, but the vibration environment of the front wheel of the road roller is harsh and the space is small. If the electric machine and the speed reducer are used for driving, the reliability will be reduced, and faults such as damage of the electric machine, leakage of electricity and leakage of cooling liquid are likely to occur. In addition, the axial size of the electric machine and the speed reducer is large, and it is not easy to meet the design requirements of three-in-one, and it is not easy to use the electric machine and the speed reducer for driving in terms of structural size.

[0061] Therefore, the present application provides a driving system of a road roller, a driving system control method of the road roller and the road roller, which will be described in detail below.

[0062] The application is described below Figures 1 to 5 A method for controlling a driving system of a road roller is provided.

[0063] Figure 1 A method for controlling a driving system of a road roller is provided.

[0064] As Figure 1 shown, the method for controlling a driving system of a road roller provided by the embodiment can be applied to a road roller and can be executed by the road roller or software and / or hardware therein, for example, by a controller in the road roller, which can be a vehicle control unit (VCU). The VCU is a vehicle controller. The method for controlling a driving system of a road roller at least includes the following steps:

[0065] In step 101, a target speed of the road roller is determined. The driving system of the road roller includes a hydraulic driving system of front wheels and an electric driving system of rear wheels. The hydraulic driving system of the front wheels includes a travel motor and a travel pump. The electric driving system of the rear wheels includes a rear-drive motor.

[0066] The method for controlling a driving system of a road roller provided by the embodiment can be implemented based on a new driving system of a road roller, which includes a hydraulic driving system of front wheels and an electric driving system of rear wheels.

[0067] The electric driving system of the rear wheels can include a rear-drive motor. The rear-drive motor is connected to the rear wheels. In addition, considering that the speed of the rear-drive motor is relatively high and the speed requirement of an actual road roller is relatively low, the rear-drive motor can be connected to a rear axle through a speed reducer to increase torque, that is, the rear-drive motor can be connected to the corresponding rear axle of the rear wheels through the speed reducer.

[0068] The hydraulic driving system of the front wheels can include a travel motor and a travel pump. The front wheels can be single steel wheels. The travel motor is connected to the front wheels, and the travel pump is connected to the travel motor. The travel motor is a hydraulic motor. The hydraulic motor is connected to the front wheels through a speed reducer.

[0069] An exemplary Figure 2 driving system of a road roller is shown, which includes a travel pump, a travel motor, a rear-drive motor, a rear axle, a power source, a high-pressure box, a multi-in-one assembly, an integrated electric drive assembly, a vibration pump, an auxiliary pump, a vibration motor, a steering gear, a brake valve, an electric air conditioner, a battery (for example, a 24V battery), a low-voltage system, and the like.

[0070] The multi-in-one assembly is connected to the rear-drive motor, the high-pressure box, the battery, the electric air conditioner, and the integrated electric drive assembly, respectively. The multi-in-one assembly can be implemented by a motor control unit (MCU), which is denoted as MCU1 and can control the connected components.

[0071] The integrated electric drive assembly is connected with the traveling pump, the vibration pump and the auxiliary pump respectively. The integrated electric drive assembly can be implemented by using an MCU and a motor, and the MCU used by the integrated electric drive assembly can be denoted as MCU2, which can supply power for the connected traveling pump, vibration pump and auxiliary pump.

[0072] The storage battery is connected with the low-voltage system to supply power for the low-voltage system. The low-voltage system can include an operation part such as a button, a handle, a pedal, an angle sensor and the like for sending a driver operation instruction, a device such as a VCU, an MCU and the like for providing signal processing, and an execution device such as an electrically controlled valve, a steering gear and the like.

[0073] The vibration pump is connected with a vibration motor, and the vibration motor is connected with an eccentric block to make the front wheels vibrate.

[0074] The auxiliary pump is connected with a steering gear and a brake valve for steering and braking.

[0075] The high-voltage box is also connected with a power source, which can distribute the power of the power source and can also be connected with a ground charging machine to charge the power source. The power source can be implemented by using a power battery, i.e., a pure electric scheme. The power source can also be implemented by using an engine, a generator and a power battery in series or in series-parallel. The power source can also be implemented by using an engine and a power battery in parallel.

[0076] Figure 2 The traveling pump, the vibration pump and the auxiliary pump are collectively powered by the integrated electric drive assembly, which is a integrated scheme. Alternatively, a discrete scheme can also be used, for example Figure 3 The driving system of the road roller shown in Figure 2 differs from that of in that a front drive motor is added, which is connected with the all-in-one assembly to supply power for the traveling pump and the vibration pump, while the integrated electric drive assembly supplies power for the auxiliary pump, which is powered individually to reduce energy consumption. Further, for example Figure 4 The driving system of the road roller shown in Figure 3 differs from that of in that the front drive motor supplies power for the traveling pump, while the integrated electric drive assembly supplies power for the auxiliary pump and the vibration pump.

[0077] The VCU can be connected with the all-in-one assembly and the integrated electric drive assembly to send a CAN signal, and can also be connected with the traveling pump and the traveling motor to send a current signal.

[0078] In actual application, the driver can control the road roller by operating the operation part such as button, handle, pedal, steering wheel, etc. The operation part feeds back the low-voltage signal such as switch quantity / analogue quantity to the VCU. The VCU receives the signals such as parking signal from the button or handle, brake signal from the pedal or handle, throttle signal from the pedal or handle, vibration signal from the button, and steering signal from the steering wheel, analyzes the received signals, generates corresponding instructions, and sends the instructions to the corresponding execution device for control. The execution device performs corresponding actions by transferring energy such as electric energy, hydraulic pressure, and mechanical energy. Based on the parking signal, the speed reducer can be released or parked, and the parking mode can be entered. Based on the brake signal, the electric brake or hydraulic brake can be controlled. Based on the vibration signal, the displacement of the vibration pump can be controlled, and the road roller vibration start-stop mode can be entered. Based on the steering signal, the MCU2 can be sent to control the steering pump, steering gear, and steering cylinder to realize steering. The processes such as parking control, brake control, motor drive, hydraulic drive, vibration control, and steering control are not described here.

[0079] Here, the composite control of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels when receiving the throttle signal is described in detail.

[0080] When receiving the throttle signal from the pedal or handle, the VCU can convert the throttle signal into a speed signal. Different opening degrees of the pedal and handle stroke correspond to different proportions of speed. The specific process can be referred to related technology, which is not described here. Based on this, the target speed of the road roller can be determined based on the received throttle signal. The target speed of the road roller is converted from the throttle signal, which is the speed that the road roller needs to reach.

[0081] Step 102, based on the target speed of the road roller, the actual speed of the front wheels is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor, and the actual power of the hydraulic drive system of the front wheels after adjustment is obtained.

[0082] In actual application, when the road roller starts, the hydraulic drive system of the front wheels can be started first. In this step, based on the target speed of the road roller, the actual speed of the front wheels is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor in the hydraulic drive system of the front wheels. After adjustment, the actual power of the corresponding hydraulic drive system of the front wheels also changes, and the actual power P f of the hydraulic drive system of the front wheels after adjustment can be obtained. In implementation, the actual speed of the front wheels can be obtained by a speed sensor and sent to the VCU.

[0083] In actual application, for the hydraulic drive system of the front wheels, the actual power output by the motor to the traveling pump for supplying power to the traveling pump can be obtained as the actual power of the hydraulic drive system of the front wheels. The actual power output to the traveling pump is related to the output speed and torque, and thus the actual power output to the traveling pump can be obtained based on the output speed and torque. The torque output to the traveling pump is related to the load, which can be reflected by the hydraulic system pressure P of the hydraulic drive system of the front wheels, and thus the torque output to the traveling pump can be calculated based on the hydraulic system pressure P of the hydraulic drive system of the front wheels. The specific calculation method can refer to related technical implementation, which will not be described here.

[0084] In order to improve the driving efficiency, the motor for supplying power to the traveling pump can operate at a fixed rotation direction and a fixed speed, which can be a preset speed interval with the best working efficiency. For example, the motor for supplying power to the traveling pump can operate at a fixed rotation direction and a fixed speed in the preset speed interval with the best working efficiency. Figure 2 For example, the driving system of the road roller shown in FIG. 1 can control the speed of the motor in the integrated electric drive assembly through the IGBT switch of the MCU2.

[0085] Step 103: determining the target power of the electric drive system of the rear wheels based on the actual power of the hydraulic drive system of the front wheels and the power distribution ratio of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels.

[0086] The power distribution ratio is used to distribute the power of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels. The power distribution ratio can be reasonably set according to the actual situation of the road roller. In this step, specifically, the actual power P of the hydraulic drive system of the front wheels can be directly multiplied by the power distribution ratio i to obtain the target power P of the electric drive system of the rear wheels. f b That is:

[0087] P b = P f / i F (1)

[0088] Where i F is the power distribution ratio.

[0089] Of course, the ratio of the actual power of the hydraulic drive system of the front wheels to the power distribution ratio can also be corrected (for example, a set correction amount is added) to obtain the target power of the electric drive system of the rear wheels. The target power of the electric drive system of the rear wheels is the power that the electric drive system of the rear wheels needs to reach.

[0090] Step 104: adjusting the actual speed of the rear wheels and the actual power of the electric drive system by controlling the torque and speed output by the rear motor based on the target speed of the road roller and the target power of the electric drive system of the rear wheels.

[0091] ​Among them, the power of the electric drive system of the rear wheel includes the power of the rear drive motor. The target power of the rear drive motor can be used as the target power of the electric drive system of the rear wheel, and the actual power of the rear drive motor can be used as the actual power of the electric drive system of the rear wheel. The actual speed of the rear wheel is related to the speed output by the rear drive motor, and the power of the rear drive motor is related to the speed and torque output by the rear drive motor. Therefore, the actual speed of the rear wheel and the actual power of the electric drive system can be adjusted by controlling the torque and speed output by the rear drive motor. In implementation, the VCU can send a CAN signal to the MCU1, so that the MCU1 adjusts the IGBT switch to adjust the voltage frequency and output current to achieve control of the speed and torque of the rear drive motor, that is, to achieve control of the actual power of the electric drive system of the rear wheel. In implementation, based on the speed feedback of the rotary transformer in the rear drive motor, combined with the parameters of the whole vehicle such as the speed ratio and the wheel, the actual speed of the rear wheel can be determined. For details, please refer to the relevant technical implementation, which will not be described here.

[0092] In this step, the target speed of the roller is used as the target, and the actual speed of the rear wheels is adjusted by controlling the torque and speed output by the rear drive motor in the electric drive system of the rear wheels.

[0093] It should be noted that the above steps 102 to 104 may be repeatedly executed until the actual speed of the roller reaches the target speed of the roller.

[0094] The rear axle is rigidly connected to the entire roller vehicle. Therefore, the actual speed of the rear wheels can reflect the actual speed of the entire roller vehicle. By adjusting the actual speed of the rear wheels to achieve the target speed of the roller, the actual speed of the roller can be achieved.

[0095] In this embodiment, since the roller's drive system includes a front wheel hydraulic drive system and a rear wheel electric drive system, the front wheels can be driven by the travel pump and travel motor of the front wheel hydraulic drive system, while the rear wheels can be driven by the rear drive motor of the rear wheel electric drive system. This realizes a dual-drive system for the roller, avoids the problems of a single rear wheel drive system, improves the overall machine's adhesion, and increases traction, thereby meeting the requirements of steep slopes and improving construction quality. The roller's drive system can determine a target speed for the roller. Based on the target speed, the actual speed of the front wheels is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor. Based on the actual power of the front wheel hydraulic drive system and the power distribution ratio between the front wheel hydraulic drive system and the rear wheel electric drive system, a reasonable target power of the rear wheel electric drive system is obtained. Combined with the target speed of the roller, the actual speed of the rear wheels and the actual power of the electric drive system are adjusted by controlling the torque and speed output by the rear drive motor, thereby realizing composite control of the front wheel hydraulic drive system and the rear wheel electric drive system.

[0096] In addition, since the rear wheels of the road roller are driven by the electric drive system, compared with the full-hydraulic double-drive scheme, the efficiency is improved. Since the front wheels of the road roller are driven by the hydraulic drive system, the hydraulic drive system is more suitable for the vibration environment, is less prone to failure, has higher reliability, and reduces the axial size of the road roller, thereby facilitating the design requirement of the three-in-one road roller.

[0097] Based on the above embodiment, the power distribution ratio is determined by determining the ratio of the maximum adhesion corresponding to the front axle of the road roller to the maximum adhesion corresponding to the rear axle of the road roller as the power distribution ratio.

[0098] The adhesion represents the adhesion of the tire of the road roller to the road surface, and is related to factors such as the weight of the road roller, the material of the front wheels and the rear wheels, and the like. For example, the power distribution ratio i can be determined based on the adhesion coefficient μ f of the front wheels, the adhesion coefficient μ b of the rear wheels, the rolling resistance coefficient f f of the front wheels, the rolling resistance coefficient f b of the rear wheels, the radius r f of the front wheels, the radius r b of the rear wheels, the height of the center of gravity h of the road roller, the distance L a between the center of gravity and the front axle, the distance L b between the center of gravity and the rear axle, and the wheelbase L. F The front axle is also referred to as the front axle. The rear axle is also referred to as the rear axle. The wheelbase is the distance between the center of the front axle and the center of the rear axle. In actual application, the confidence interval of the adhesion coefficient of the front wheels and the adhesion coefficient of the rear wheels can be measured by experiment.

[0099] Specifically, the power distribution ratio can be determined by the following formula:

[0100]

[0101] Through the above formula, the power distribution ratio can be calculated in the pre-design process of the road roller, and the program code is written into the VCU to facilitate power distribution.

[0102] In this embodiment, the power distribution ratio is determined according to the adhesion of the front wheels and the rear wheels, and the power of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels is reasonably distributed by using the power distribution ratio, thereby improving the control accuracy of the drive system.

[0103] In addition, the above power distribution ratio can also be determined according to experience statistics.

[0104] Based on the above embodiment, based on the target speed of the road roller, the actual speed of the front wheels is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor, as shown in the following formula: Figure 5 The specific implementation manner can include:

[0105] Step 501, based on the steering angle, determine the front-rear wheel speed difference, the front-rear wheel speed difference is used to represent the difference between the target speed of the front wheel and the target speed of the rear wheel.

[0106] In practical application, the number of turns of the steering wheel can reflect the steering angle, which can be measured by an angle sensor.

[0107] For example, when determining the front-rear wheel speed difference based on the steering angle, the steering angle can be used to calculate the front wheel turning radius and the rear wheel turning radius, the difference between the paths of the front wheel and the rear wheel can be determined based on the front wheel turning radius and the rear wheel turning radius, and the front-rear wheel speed difference can be calculated based on the difference between the paths. The specific implementation of this scheme can be referred to related technologies, which will not be described in detail here.

[0108] Step 502, based on the target speed of the road roller and the front-rear wheel speed difference, determine the target speed of the front wheel.

[0109] Specifically, the sum of the target speed v1 of the road roller and the front-rear wheel speed difference Δv is used to obtain the target speed v2 of the front wheel. For example, the calculation formula of the target speed v2 of the front wheel is as follows:

[0110] v2=v1+Δv (3)

[0111] When the road roller is driving straight, since it is not steering, Δv is zero, and finally v2=v1.

[0112] In the steering mode, since steering is required, the front wheel and the rear wheel need to produce a speed difference, Δv is not zero, based on this, the actual speed v4 of the rear wheel can be made to be v1, and the actual speed v3 of the front wheel is greater than v4, so that the road roller can be steered at a certain angle.

[0113] Step 503, based on the target speed of the front wheel, adjust the actual speed of the front wheel by controlling the displacement of the travel pump and the displacement of the travel motor.

[0114] The speed of the front wheel is related to a variety of factors, as shown in the following formula:

[0115]

[0116] Wherein, i g represents the speed ratio of the corresponding speed reducer of the front wheel, r d represents the radius of the front wheel steel wheel, N represents the speed of the motor supplying power to the travel pump, V p represents the displacement of the travel pump, V m represents the displacement of the travel motor, and η represents the volumetric efficiency of the hydraulic system. The confidence interval of the value of the volumetric efficiency of the hydraulic system can be measured by experiment.

[0117] Based on the above formula (4), it can be seen that the target speed of the front wheel is related to the displacement of the traveling pump and the displacement of the traveling motor, and therefore, the actual speed of the front wheel can be adjusted by controlling the displacement of the traveling pump and the displacement of the traveling motor. The VCU can control the current signal output to the traveling pump to control the displacement of the traveling pump, and control the current signal output to the traveling motor to control the displacement of the traveling motor.

[0118] In the embodiment, since the speed difference between the front and rear wheels is related to the steering angle, the speed difference between the front and rear wheels can be accurately determined through the steering angle, and then the target speed of the front wheel is determined in combination with the target speed of the road roller. Then, the target speed of the front wheel is taken as the target, and the actual speed of the front wheel is quickly and accurately adjusted by controlling the displacement of the traveling pump and the displacement of the traveling motor.

[0119] Based on the above embodiment, the actual speed of the front wheel is adjusted by controlling the displacement of the traveling pump and the displacement of the traveling motor based on the target speed of the front wheel, and the specific implementation manner can include:

[0120] If it is determined that the actual speed of the rear wheel is greater than the target speed of the road roller, the road roller is braked so that the actual speed of the rear wheel is less than or equal to the target speed of the road roller, and the speed adjustment step is performed.

[0121] If it is determined that the actual speed of the rear wheel is less than or equal to the target speed of the road roller, the speed adjustment step is performed.

[0122] The speed adjustment step includes: obtaining a preset corresponding relationship, the corresponding relationship including a speed range corresponding to each gear of the displacement of the traveling motor; based on the target speed of the front wheel and the corresponding relationship, the actual speed of the front wheel is adjusted by controlling the displacement of the traveling pump and the displacement of the traveling motor.

[0123] In actual application, in the driving mode, i.e., when the driver controls the speed of the road roller to be increased, v4 < v1, the actual speed of the front wheel can be directly adjusted through the above speed adjustment step. In the braking mode, i.e., when the driver controls the speed of the road roller to be decreased, v4 > v1, then the road roller needs to be braked first so that v4 ≤ v1, and then the actual speed of the front wheel is finely adjusted through the above speed adjustment step. When the road roller is braked, v4 = v1 can be achieved, but considering that the control accuracy is required to be high during braking, v4 < v1 can also be achieved.

[0124] In the embodiment, in order to reduce the vibration caused by displacement switching and ensure the stability of traction, multiple gears are set for the displacement of the traveling motor in the speed adjusting step, each gear corresponds to a speed range, and the displacement of the traveling pump and the displacement of the traveling motor are controlled based on the multiple gears, so as to adjust the actual speed of the front wheels.

[0125] In the implementation, the minimum displacement threshold of the traveling motor can be determined in advance according to the maximum vehicle speed designed in advance for the road roller and the maximum displacement of the traveling pump, the maximum displacement threshold of the traveling motor is determined according to the maximum climbing degree designed in advance for the road roller and the maximum pressure of the hydraulic system, wherein the maximum pressure of the hydraulic system is determined by the selection of each hydraulic component, and then multiple displacements are set between the minimum displacement threshold and the maximum displacement threshold of the traveling motor to obtain multiple gears of the displacement of the traveling motor, and the speed range corresponding to each gear of the displacement of the traveling motor is determined.

[0126] Based on the above embodiment, the actual speed of the front wheels is adjusted by controlling the displacement of the traveling pump and the displacement of the traveling motor based on the target speed of the front wheels and the corresponding relationship, and the specific implementation manner can include:

[0127] If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is greater than or equal to the target speed of the front wheels, the first target displacement of the traveling pump corresponding to the target speed of the front wheels is determined at the current gear of the displacement of the traveling motor, and the actual speed of the front wheels is adjusted by adjusting the displacement of the traveling pump to the target displacement.

[0128] If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is less than the target speed of the front wheels, the current gear of the displacement of the traveling motor is gradually reduced, and when the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is greater than or equal to the target speed of the front wheels, the reduction of the current gear of the displacement of the traveling motor is stopped, and the first target displacement of the traveling pump corresponding to the target speed of the front wheels is determined at the current gear of the displacement of the traveling motor, and the actual speed of the front wheels is adjusted by adjusting the displacement of the traveling pump to the target displacement.

[0129] For example, the first target displacement of the traveling pump corresponding to the target speed of the front wheels can be determined in combination with formula (4).

[0130] Here, the first target displacement is the displacement that the traveling pump needs to reach.

[0131] In this embodiment, the adjustment of the current gear position of the displacement of the travel motor is performed in combination with the size relationship between the maximum value of the speed range corresponding to the current gear position of the displacement of the travel motor and the target speed of the front wheels, and if the speed range under the current gear position of the displacement of the travel motor can meet the target speed of the front wheels, the adjustment of the displacement of the travel pump can be performed, and when v4 < v1, the actual speed of the front wheels can be increased by increasing the displacement of the travel pump, so that the actual speed of the front wheels can be smoothly adjusted to the target speed of the front wheels quickly and accurately.

[0132] Based on the above embodiment, after adjusting the actual speed of the front wheels by adjusting the displacement of the travel pump to the target displacement, the method can further include: if the difference between the actual speed of the front wheels and the target speed of the front wheels is greater than or equal to a preset difference value, correcting the volumetric efficiency of the hydraulic system of the front wheel drive system, determining the second target displacement of the travel pump corresponding to the target speed of the front wheels based on the corrected volumetric efficiency of the hydraulic system under the current gear position of the displacement of the travel motor, and adjusting the displacement of the travel pump to the second target displacement to make the difference between the actual speed of the front wheels and the target speed of the front wheels less than the preset difference value.

[0133] The second target displacement here is the displacement that the travel pump needs to reach.

[0134] In theory, after adjusting the displacement of the travel pump to the first target displacement, the actual speed v3 of the front wheels is equal to the target speed v2 of the front wheels, but due to factors such as the volumetric efficiency of the hydraulic system, there is a certain difference between the two, at this time, the VCU can correct the volumetric efficiency according to a preset correction strategy. Since the volumetric efficiency of the hydraulic system is variable, when correcting, the volumetric efficiency of the hydraulic system is adjusted based on formula (4), the displacement of the travel pump after adjustment is calculated, the second target displacement is obtained, the target speed v2 of the front wheels is guaranteed, and the difference between the actual speed of the front wheels after correction and the target speed of the front wheels is less than the preset difference value. In the driving mode, the final correction can be v2 = v1.

[0135] Based on the above embodiment, the road roller is braked, and the specific implementation manner can include:

[0136] Firstly, an electric braking condition of the road roller is obtained, the electric braking condition including a first condition and a second condition, the first condition including that the electric quantity of the power supply of the road roller is less than or equal to a preset electric quantity, and the second condition including that the braking force required by the road roller is less than or equal to a preset braking force.

[0137] The preset electric quantity can be set according to actual conditions, and for example, the preset electric quantity can be 95% SOC. The preset braking force includes the braking torque corresponding to the braking force that can be provided by the rear-drive motor and the corresponding speed reducer.

[0138] Second step, if it is determined that the road roller meets the first condition and does not meet the second condition, based on the corresponding relationship, the actual speed of the front wheel is reduced by controlling the displacement of the traveling pump and the displacement of the traveling motor, so that the road roller meets the electric braking condition.

[0139] In practical application, when the required braking force is large, the demand for braking force can be reduced by reducing the actual speed of the front wheel, so that the road roller meets the electric braking condition.

[0140] Specifically, based on the corresponding relationship, the actual speed of the front wheel is reduced by controlling the displacement of the traveling pump and the displacement of the traveling motor, so that the road roller meets the electric braking condition, which can include:

[0141] If it is determined that the target speed of the front wheel is greater than the maximum value of the speed range corresponding to the last gear of the current gear of the displacement of the traveling motor, the actual speed of the front wheel is reduced by reducing the displacement of the traveling pump under the current gear of the displacement of the traveling motor.

[0142] If it is determined that the target speed of the front wheel is less than or equal to the maximum value of the speed range corresponding to the last gear of the current gear of the displacement of the traveling motor, the current gear of the displacement of the traveling motor is gradually increased, and when the target speed of the front wheel is greater than the maximum value of the speed range corresponding to the last gear of the current gear of the displacement of the traveling motor, the current gear of the displacement of the traveling motor is stopped increasing, and the actual speed of the front wheel is reduced by reducing the displacement of the traveling pump under the current gear of the displacement of the traveling motor.

[0143] In this way, when the actual speed of the front wheel is reduced, the gear of the displacement of the traveling motor is adjusted according to the relationship between the maximum value of the speed range corresponding to the last gear of the current gear of the displacement of the traveling motor and the target speed of the front wheel, and if the speed range under the current gear of the displacement of the traveling motor can meet the target speed of the front wheel, the displacement of the traveling pump can be adjusted, the actual speed of the front wheel is reduced by reducing the displacement of the traveling pump, so that the actual speed of the front wheel is stably reduced quickly and accurately.

[0144] Third step, if it is determined that the road roller meets the electric braking condition, the rear drive motor is controlled to perform brake energy recovery.

[0145] It should be noted that during the process of controlling the rear drive motor to perform brake energy recovery, the displacement of the traveling motor needs to approach zero to avoid hindering brake energy recovery. A fixed displacement value can be selected near zero to adjust the displacement of the traveling motor to the fixed displacement value. When v4≤v1, brake energy recovery can be stopped.

[0146] In this embodiment, brake energy recovery is performed by the rear drive motor of the electric drive system of the rear wheel, which brakes quickly and reduces energy waste.

[0147] The driving system control device of the road roller provided by the present invention is described below. The driving system control device of the road roller described below and the driving system control method of the road roller described above can be referred to in correspondence with each other.

[0148] like Figure 6 As shown, this embodiment provides a driving system control device for a road roller, comprising:

[0149] Speed ​​determination module 601, for determining the target speed of the roller; the roller's drive system includes a front wheel hydraulic drive system and a rear wheel electric drive system, the front wheel hydraulic drive system includes a travel motor and a travel pump, and the rear wheel electric drive system includes a rear drive motor;

[0150] The front wheel adjustment module 602 is used to adjust the actual speed of the front wheels by controlling the displacement of the travel pump and the displacement of the travel motor based on the target speed of the roller, and obtain the actual power of the hydraulic drive system of the front wheels after adjustment;

[0151] a power distribution module 603 for determining a target power of the rear wheel electric drive system based on the actual power of the front wheel hydraulic drive system and the power distribution ratio between the front wheel hydraulic drive system and the rear wheel electric drive system;

[0152] The rear wheel adjustment module 604 is used to adjust the actual speed of the rear wheels and the actual power of the electric drive system by controlling the torque and speed output by the rear drive motor based on the target speed of the roller and the target power of the electric drive system of the rear wheels.

[0153] Based on the above embodiment, the power allocation ratio is determined by:

[0154] The ratio of the maximum adhesion corresponding to the front axle of the roller to the maximum adhesion corresponding to the rear axle of the roller is determined as the power distribution ratio.

[0155] Based on the above embodiment, the front wheel adjustment module 602 is specifically configured to:

[0156] Based on the steering angle, the front and rear wheel speed difference is determined, and the front and rear wheel speed difference is used to represent the difference between the target speed of the front wheels and the target speed of the rear wheels;

[0157] Determine the target speed of the front wheel based on the target speed of the roller and the speed difference between the front and rear wheels;

[0158] Based on the target speed of the front wheels, the actual speed of the front wheels is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor.

[0159] Based on the above embodiment, the front wheel adjustment module 602 is specifically configured to:

[0160] If it is determined that the actual speed of the rear wheel is greater than the target speed of the road roller, the road roller is braked so that the actual speed of the rear wheel is less than or equal to the target speed of the road roller, and the speed adjustment step is performed;

[0161] If it is determined that the actual speed of the rear wheel is less than or equal to the target speed of the road roller, the speed adjustment step is performed;

[0162] The speed adjustment step includes:

[0163] The preset corresponding relationship includes a speed range corresponding to each gear of the displacement of the travel motor;

[0164] Based on the target speed of the front wheel and the corresponding relationship, the actual speed of the front wheel is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor.

[0165] Based on the above embodiment, the front wheel adjustment module 602 is specifically configured to:

[0166] If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the travel motor is greater than or equal to the target speed of the front wheel, a first target displacement of the travel pump corresponding to the target speed of the front wheel is determined at the current gear of the displacement of the travel motor, and the actual speed of the front wheel is adjusted by adjusting the displacement of the travel pump to the target displacement;

[0167] If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the travel motor is less than the target speed of the front wheel, the current gear of the displacement of the travel motor is gradually reduced, and when the maximum value of the speed range corresponding to the current gear of the displacement of the travel motor is greater than or equal to the target speed of the front wheel, the reduction of the current gear of the displacement of the travel motor is stopped, and a first target displacement of the travel pump corresponding to the target speed of the front wheel is determined at the current gear of the displacement of the travel motor, and the actual speed of the front wheel is adjusted by adjusting the displacement of the travel pump to the target displacement.

[0168] Based on the above embodiment, the front wheel adjustment module 602 is further configured to:

[0169] If the difference between the actual speed of the front wheel and the target speed of the front wheel is greater than or equal to a preset difference value, the volumetric efficiency of the hydraulic system of the front wheel driving system is corrected, a second target displacement of the travel pump corresponding to the target speed of the front wheel is determined based on the volumetric efficiency of the corrected hydraulic system at the current gear of the displacement of the travel motor, and the displacement of the travel pump is adjusted to the second target displacement so that the difference between the actual speed of the front wheel and the target speed of the front wheel is less than the preset difference value.

[0170] Based on the above embodiment, the front wheel adjustment module 602 is specifically configured to:

[0171] obtaining an electric braking condition of the road roller, the electric braking condition including a first condition and a second condition, the first condition including that an electric quantity of an electric power source of the road roller is less than or equal to a preset electric quantity, and the second condition including that a braking force required by the road roller is less than or equal to a preset braking force;

[0172] if it is determined that the road roller satisfies the first condition and does not satisfy the second condition, based on the corresponding relationship, the actual speed of the front wheels is reduced by controlling the displacement of the traveling pump and the displacement of the traveling motor, so that the road roller satisfies the electric braking condition;

[0173] if it is determined that the road roller satisfies the electric braking condition, the regenerative braking of the road roller is controlled by controlling the rear-drive motor.

[0174] Based on the above embodiment, the front wheel adjusting module 602 is specifically used for:

[0175] if it is determined that the target speed of the front wheels is greater than the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the actual speed of the front wheels is reduced by reducing the displacement of the traveling pump under the current gear of the displacement of the traveling motor;

[0176] if it is determined that the target speed of the front wheels is less than or equal to the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the current gear of the displacement of the traveling motor is gradually increased, and when the target speed of the front wheels is greater than the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the increasing of the current gear of the displacement of the traveling motor is stopped, and the actual speed of the front wheels is reduced by reducing the displacement of the traveling pump under the current gear of the displacement of the traveling motor.

[0177] The embodiment of the application also provides a driving system of a road roller for implementing the driving system control method of the road roller provided in any one of the above embodiments, comprising a vehicle controller, a hydraulic driving system of front wheels and an electric driving system of rear wheels; wherein the hydraulic driving system of the front wheels comprises a traveling motor and a traveling pump; the electric driving system of the rear wheels comprises a rear-drive motor;

[0178] The vehicle controller is in communication connection with the hydraulic driving system of the front wheels and the electric driving system of the rear wheels.

[0179] The vehicle controller is used for executing the driving system control method of the road roller provided in any one of the above embodiments.

[0180] In the embodiment, since the driving system of the road roller comprises the hydraulic driving system of the front wheels and the electric driving system of the rear wheels, the front wheels can be driven by the traveling pump and the traveling motor of the hydraulic driving system of the front wheels, and the rear wheels can be driven by the rear-drive motor of the electric driving system of the rear wheels, so that the double driving system of the road roller is realized, the problems of the single driving system of the rear wheels are avoided, the adhesion of the whole machine is improved, the traction is increased, the requirements of a steeper slope can be met, and the construction quality is improved. The target speed of the road roller can be determined for the driving system of the road roller, the actual speed of the front wheels is adjusted based on the target speed by controlling the displacement of the traveling pump and the displacement of the traveling motor, the target power of the electric driving system of the rear wheels is obtained based on the actual power of the hydraulic driving system of the front wheels and the power distribution ratio of the hydraulic driving system of the front wheels and the electric driving system of the rear wheels, and the actual speed of the rear wheels and the actual power of the electric driving system are adjusted by controlling the torque and the rotating speed output by the rear-drive motor in combination with the target speed of the road roller, so that the compound control of the hydraulic driving system of the front wheels and the electric driving system of the rear wheels is realized.

[0181] The rear-drive motor is connected with the rear wheels through a speed reducer, and / or the traveling motor is connected with the front wheels through a speed reducer.

[0182] Based on the above embodiment, the driving system of the road roller provided in the embodiment further comprises a multi-in-one assembly, a vibration pump and an auxiliary pump for steering and braking.

[0183] The driving system of the road roller further comprises an integrated electric drive assembly connected with the vehicle controller, and the multi-in-one assembly is connected with the rear-drive motor and the integrated electric drive assembly; or the driving system of the road roller further comprises a front-drive motor and an integrated electric drive assembly connected with the vehicle controller, and the multi-in-one assembly is connected with the rear-drive motor, the front-drive motor and the integrated electric drive assembly; or the driving system of the road roller further comprises a front-drive motor and an integrated electric drive assembly connected with the vehicle controller, and the multi-in-one assembly is connected with the rear-drive motor, the front-drive motor and the integrated electric drive assembly; or the driving system of the road roller further comprises a front-drive motor and an integrated electric drive assembly connected with the vehicle controller, and the multi-in-one assembly is connected with the rear-drive motor, the front-drive motor and the integrated electric drive assembly.

[0184] The driving system of the road roller provided in the embodiment can be correspondingly referred to the driving system control method of the road roller described above, and details are not described herein.

[0185] Figure 7 An example of an electronic device is shown in a schematic view of a physical structure, such as Figure 7As shown, the electronic device can include a processor 710, a communications interface 720, a memory 730, and a communications bus 740, wherein the processor 710, the communications interface 720, and the memory 730 complete mutual communication through the communications bus 740. The processor 710 can invoke a logic instruction in the memory 730 to execute a drive system control method of a road roller, the method comprising:

[0186] determining a target speed of the road roller; the drive system of the road roller includes a hydraulic drive system of front wheels and an electric drive system of rear wheels, the hydraulic drive system of the front wheels includes a travel motor and a travel pump, and the electric drive system of the rear wheels includes a rear-drive motor;

[0187] based on the target speed of the road roller, adjusting an actual speed of the front wheels by controlling a displacement of the travel pump and a displacement of the travel motor, and obtaining an actual power of the hydraulic drive system of the front wheels;

[0188] based on the actual power of the hydraulic drive system of the front wheels and a power distribution ratio of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels, determining a target power of the electric drive system of the rear wheels;

[0189] based on the target speed of the road roller and the target power of the electric drive system of the rear wheels, adjusting an actual speed of the rear wheels and an actual power of the electric drive system by controlling a torque and a rotating speed output by the rear-drive motor.

[0190] In addition, the logic instruction in the memory 730 described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0191] In another aspect, the present application also provides a computer program product, which comprises a computer program stored on a computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the method of controlling a drive system of a road roller as described above, the method comprising:

[0192] determining a target speed of the road roller; the drive system of the road roller comprises a hydraulic drive system of front wheels and an electric drive system of rear wheels, the hydraulic drive system of the front wheels comprises a travel motor and a travel pump, the electric drive system of the rear wheels comprises a rear drive motor;

[0193] based on the target speed of the road roller, adjusting an actual speed of the front wheels by controlling a displacement of the travel pump and a displacement of the travel motor, and obtaining an actual power of the hydraulic drive system of the front wheels;

[0194] based on the actual power of the hydraulic drive system of the front wheels and a power distribution ratio of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels, determining a target power of the electric drive system of the rear wheels;

[0195] based on the target speed of the road roller and the target power of the electric drive system of the rear wheels, adjusting an actual speed of the rear wheels and an actual power of the electric drive system by controlling a torque and a rotating speed output by the rear drive motor.

[0196] In yet another aspect, the present application also provides a computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the method of controlling a drive system of a road roller as described above, the method comprising:

[0197] determining a target speed of the road roller; the drive system of the road roller comprises a hydraulic drive system of front wheels and an electric drive system of rear wheels, the hydraulic drive system of the front wheels comprises a travel motor and a travel pump, the electric drive system of the rear wheels comprises a rear drive motor;

[0198] based on the target speed of the road roller, adjusting an actual speed of the front wheels by controlling a displacement of the travel pump and a displacement of the travel motor, and obtaining an actual power of the hydraulic drive system of the front wheels;

[0199] based on the actual power of the hydraulic drive system of the front wheels and a power distribution ratio of the hydraulic drive system of the front wheels and the electric drive system of the rear wheels, determining a target power of the electric drive system of the rear wheels;

[0200] based on the target speed of the road roller and the target power of the electric drive system of the rear wheels, adjusting an actual speed of the rear wheels and an actual power of the electric drive system by controlling a torque and a rotating speed output by the rear drive motor.

[0201] In yet another aspect, the present application also provides a road roller, comprising a road roller body, wherein the road roller body is provided with the driving system of the road roller according to any one of the above embodiments, or the driving system control device of the road roller according to any one of the above embodiments, or the electronic device according to any one of the above embodiments, or the computer readable storage medium according to any one of the above embodiments.

[0202] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, i.e., may be located in one place, or may be distributed to multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0203] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be realized by means of software and the necessary general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0204] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling a driving system of a road roller, characterized in that: include: determining a target speed of the roller; the roller drive system includes a front wheel hydraulic drive system and a rear wheel electric drive system, the front wheel hydraulic drive system includes a travel motor and a travel pump, and the rear wheel electric drive system includes a rear drive motor; wherein, when the roller is started, the front wheel hydraulic drive system is first started, and a front and rear wheel speed difference is determined based on a steering angle, the front and rear wheel speed difference being used to represent a difference between a target speed of the front wheel and a target speed of the rear wheel; and determining the target speed of the front wheel based on the target speed of the roller and the front and rear wheel speed difference; Based on the target speed of the front wheels of the road roller, the actual speed of the front wheels is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor, and the actual power of the hydraulic drive system of the front wheels after the adjustment is obtained; determining a target power of the electric drive system of the rear wheels based on the actual power of the hydraulic drive system of the front wheels and the power distribution ratio between the hydraulic drive system of the front wheels and the electric drive system of the rear wheels; wherein the power distribution ratio is determined by determining a ratio of a maximum adhesion corresponding to a front axle of the roller to a maximum adhesion corresponding to a rear axle of the roller as the power distribution ratio; Based on the target speed of the roller and the target power of the electric drive system of the rear wheels, the actual speed of the rear wheels and the actual power of the electric drive system are adjusted by controlling the torque and speed output by the rear drive motor.

2. The method for controlling a driving system of a road roller according to claim 1, wherein: The adjusting the actual speed of the front wheel by controlling the displacement of the travel pump and the displacement of the travel motor based on the target speed of the front wheel of the road roller includes: If it is determined that the actual speed of the rear wheel is greater than the target speed of the roller, braking the roller so that the actual speed of the rear wheel is less than or equal to the target speed of the roller, and performing a speed adjustment step; If it is determined that the actual speed of the rear wheel is less than or equal to the target speed of the roller, executing the speed adjustment step; Wherein, the speed adjustment step includes: Acquiring a preset corresponding relationship, wherein the corresponding relationship includes a speed range corresponding to each of a plurality of gears of the displacement of the travel motor; Based on the target speed of the front wheel and the correspondence, the actual speed of the front wheel is adjusted by controlling the displacement of the travel pump and the displacement of the travel motor.

3. The method for controlling a driving system of a road roller according to claim 2, wherein: The adjusting the actual speed of the front wheel by controlling the displacement of the travel pump and the displacement of the travel motor based on the target speed of the front wheel and the corresponding relationship includes: If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the travel motor is greater than or equal to the target speed of the front wheel, determining a first target displacement of the travel pump corresponding to the target speed of the front wheel under the current gear of the displacement of the travel motor, and adjusting the displacement of the travel pump to the first target displacement to adjust the actual speed of the front wheel; If it is determined that the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is less than the target speed of the front wheel, the current gear of the displacement of the traveling motor is controlled to gradually decrease. When the maximum value of the speed range corresponding to the current gear of the displacement of the traveling motor is greater than or equal to the target speed of the front wheel, the current gear of the displacement of the traveling motor is stopped from being reduced, and under the current gear of the displacement of the traveling motor, the first target displacement of the traveling pump corresponding to the target speed of the front wheel is determined. By adjusting the displacement of the traveling pump to the first target displacement, the actual speed of the front wheel is adjusted.

4. The method for controlling a driving system of a road roller according to claim 3, wherein: After adjusting the actual speed of the front wheel by adjusting the displacement of the travel pump to the first target displacement, the method further includes: If the difference between the actual speed of the front wheels and the target speed of the front wheels is greater than or equal to a preset difference, the volumetric efficiency of the hydraulic system of the front-wheel drive system is corrected, and at the current gear of the displacement of the travel motor, the second target displacement of the travel pump corresponding to the target speed of the front wheels is determined based on the corrected volumetric efficiency of the hydraulic system, and the displacement of the travel pump is adjusted to the second target displacement so that the difference between the actual speed of the front wheels and the target speed of the front wheels is less than the preset difference.

5. The method for controlling a driving system of a road roller according to claim 2, wherein: The step of braking the road roller comprises: Obtaining an electric braking condition of the roller, the electric braking condition including a first condition and a second condition, the first condition including that the power of the power supply of the roller is less than or equal to a preset power, and the second condition including that the braking force required by the roller is less than or equal to the preset braking force; If it is determined that the roller satisfies the first condition but does not satisfy the second condition, based on the correspondence, reducing the actual speed of the front wheel by controlling the displacement of the travel pump and the displacement of the travel motor so that the roller satisfies the electric braking condition; If it is determined that the roller meets the electric braking condition, the rear drive motor is controlled to perform braking energy recovery.

6. The method for controlling a driving system of a road roller according to claim 5, wherein: The controlling, based on the corresponding relationship, of the displacement of the travel pump and the displacement of the travel motor to reduce the actual speed of the front wheel so that the roller meets the electric braking condition includes: If it is determined that the target speed of the front wheel is greater than the maximum value of the speed range corresponding to the gear immediately preceding the current gear of the displacement of the travel motor, the actual speed of the front wheel is reduced by reducing the displacement of the travel pump at the current gear of the displacement of the travel motor; If it is determined that the target speed of the front wheel is less than or equal to the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the current gear of the displacement of the traveling motor is controlled to gradually increase. When the target speed of the front wheel is greater than the maximum value of the speed range corresponding to the previous gear of the current gear of the displacement of the traveling motor, the increase of the current gear of the displacement of the traveling motor is stopped, and under the current gear of the displacement of the traveling motor, the actual speed of the front wheel is reduced by reducing the displacement of the traveling pump.

7. A driving system for a road roller for implementing the driving system control method for a road roller according to any one of claims 1 to 6, characterized in that: Including vehicle controller; The vehicle controller is communicatively connected to the hydraulic drive system of the front wheels and the electric drive system of the rear wheels.

8. A road roller, comprising a road roller body, characterized in that: The roller body is provided with the driving system of the roller as claimed in claim 7.

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