Brake energy control method and device and engineering vehicle

Abstract

The invention relates to a braking energy control method and device and an engineering vehicle. The method comprises the steps that a braking signal is detected, braking energy to be recycled is obtained, and the electric quantity of a battery is read; in response to the condition that the battery capacity exceeds a set threshold value, acquiring state data of each operation motor; and under the condition that all the operation motors are determined to be in the idle state, the braking energy to be recycled is distributed to all the power motors and all the operation motors so as to be dissipated in a motor heating mode. By the adoption of the method, when the electric quantity of the battery is too high and braking energy cannot be recycled, the vehicle control unit can dynamically distribute energy to the idle operation motor and the power motor, excess energy is actively dissipated in a heating mode, the problem of braking energy recycling contradiction under the high-electric-quantity working condition is solved, the risk of battery overcharge is avoided through heat dissipation of the motors, and the energy utilization rate is increased. The mechanical braking dependence is reduced, the service life of a braking system is prolonged, and the smoothness and response speed of vehicle control are improved.

Description

Technical Field

[0001] This application relates to the field of engineering, and in particular to a braking energy control method, a braking energy control device, and an engineering vehicle. Background Technology

[0002] Braking energy control, which provides electric braking force to a vehicle while converting mechanical energy into electrical energy and storing it in the power battery, is one of the key technologies for reducing overall vehicle energy consumption and increasing driving range in pure electric vehicles and hybrid vehicles.

[0003] However, according to patent CN105774566A, braking energy control can only be performed when the battery charge (SOC) is between 20% and 80%. When the SOC exceeds 80%, the system will discontinue the regenerative braking function because there is nowhere to store the converted electrical energy. At this time, controlling the vehicle's deceleration and braking solely through mechanical braking force will cause the brake discs to overheat, resulting in thermal fade or accelerated wear, which in turn weakens the total braking force and increases the braking distance. At the same time, the mechanical braking response is delayed, affecting the smoothness of operation, safety, and driving experience. Summary of the Invention

[0004] Therefore, it is necessary to provide a braking energy control method, a braking energy control device, and an engineering vehicle to address the aforementioned technical problems.

[0005] In a first aspect, this application provides a braking energy control method applied to the vehicle controller of an engineering vehicle, the engineering vehicle including at least one power motor and at least one work motor, the method comprising: A braking signal is detected, the braking energy to be recovered is acquired, and the battery level is read. In response to the battery level exceeding a set threshold, a request is sent to the working motor controller; Receive the status data of each working motor from the working motor controller based on the request; When it is determined from the state data that all working motors are in an idle state, the braking energy to be recovered is distributed to each power motor and each working motor to dissipate through motor heating.

[0006] In one embodiment, the step of controlling the power motor to dissipate braking energy through heating includes: Periodic positive and negative symmetrical currents are superimposed on the operating current of the power motor so that the iron core windings heat up and dissipate braking energy. The operating current is used to drive the power motor to output the target braking torque.

[0007] In one embodiment, the step of controlling the working motor to dissipate braking energy by heating includes: The operating motor is controlled to output a periodic positive and negative symmetrical current with an average torque of zero, so that the iron core windings heat up and dissipate braking energy.

[0008] In one embodiment, the switching period of the positive and negative symmetrical currents is 0.2ms-1ms.

[0009] In one embodiment, the step of distributing the regenerated braking energy to each power motor and each working motor for dissipation through motor heating includes: The braking energy to be recovered is compared with a first preset power value; the first preset power value is the sum of the maximum heat generation power of all power motors and the maximum heat generation power of all operating motors. If the braking energy to be recovered is greater than the first preset power value, then each power motor and each working motor are controlled to generate heat at their respective maximum heating power to dissipate the braking energy to be recovered in a coordinated manner.

[0010] In one embodiment, the method further includes: The braking energy to be recovered is determined to be no greater than the first preset power value and greater than the second preset power value; the second preset power value is the sum of the maximum heat generation power of all power motors. Each power motor is controlled to generate heat at its maximum heating power to dissipate part of the braking energy, and the remaining braking energy is distributed to each working motor for dissipation.

[0011] In one embodiment, the method further includes: It is determined that the braking energy to be recovered is not greater than the second preset power value; The braking energy to be recovered is evenly distributed to each power motor for dissipation.

[0012] In one embodiment, the method further includes: If it is determined from the state data that a working motor is in operation, the braking energy to be recovered is preferentially allocated to the working motor in operation so as to dissipate it through operation. The remaining braking energy is distributed to each power motor and the idle working motor to dissipate through motor heating.

[0013] Secondly, this application also provides a braking energy control device, the device comprising: The detection module is used to detect braking signals, acquire the braking energy to be recovered, and read the battery power. The request module is used to send a request to the working motor controller in response to the battery power exceeding a set threshold. The receiving module is used to receive the status data of each working motor fed back by the working motor controller based on the request; The control module is used to distribute the braking energy to be recovered to each power motor and each working motor when it is determined from the status data that each working motor is in an idle state, so as to dissipate it through motor heating.

[0014] Thirdly, embodiments of this application provide an engineering vehicle, including a vehicle controller, a battery management system, a power battery, at least one power motor, a power motor controller, at least one work motor, and a work motor controller; the vehicle controller communicates with the battery management system, the power motor controller, and the work motor controller respectively, and the power battery is connected to the battery management system, the power motor controller, and the work motor controller respectively; The vehicle controller is used to detect braking signals, obtain the braking energy to be recovered through the power motor controller, and read the battery charge of the power battery generated by the battery management system; in response to the battery charge exceeding a set threshold, it sends a request to the working motor controller; receives the status data of each working motor fed back by the working motor controller based on the request; when it is determined based on the status data that each working motor is in an idle state, it distributes the braking energy to be recovered to each power motor and each working motor to dissipate it through motor heating.

[0015] One of the above technical solutions has the following advantages or beneficial effects: When the battery charge is too high and braking energy cannot be recovered, the vehicle controller can dynamically allocate energy to the idle working motor and the power motor, and actively dissipate excess energy in the form of heat. This solves the problem of the contradiction in braking energy recovery under high charge conditions. By dissipating the energy through motor heat, the risk of battery overcharging is avoided, the reliance on mechanical braking is reduced, the life of the braking system is extended, and the smoothness and response speed of vehicle control are improved. Attached Figure Description

[0016] Figure 1 This is an application environment diagram of the braking energy control method in one embodiment; Figure 2 This is a flowchart illustrating a braking energy control method in one embodiment; Figure 3 This is a flowchart illustrating the braking energy control method in another embodiment; Figure 4 This is a structural block diagram of a braking energy control device in one embodiment; Figure 5 This is a schematic diagram of the structure of an engineering vehicle in one embodiment. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0019] The braking energy control method provided in this application can be applied to, for example... Figure 1 The application environment shown is illustrated. The equipment in the figure can be understood as a new energy engineering vehicle. This engineering vehicle is not limited to the crane vehicle shown in the figure; it can also be a mixer truck, tractor, etc. The engineering vehicle can be a pure electric engineering vehicle, a hybrid engineering vehicle, or other types of new energy engineering vehicles. Any engineering vehicle equipped with a multi-motor system such as a work motor and a power motor can apply the braking energy control method of this application.

[0020] like Figure 1 As shown, the engineering vehicle 100 may include a vehicle controller 101, at least one power motor 102, and at least one work motor 103. The at least one power motor 102 may correspond to at least one power motor controller, and the at least one work motor 103 may correspond to at least one work motor controller. For example, when the new energy engineering vehicle 100 is a mixer truck, the work motor 103 may be a mixer drum motor; when the new energy engineering vehicle 100 is a tractor, the work motor 103 may be a front PTO motor and a rear PTO motor. The work motor 103 may also be a hydraulic pump motor, a winch motor, etc. When the new energy engineering vehicle 100 is driven by a single motor, the number of power motors 102 is one; when the new energy engineering vehicle 100 is driven by multiple motors, the number of power motors 102 is multiple.

[0021] The vehicle controller 101 can perform vehicle energy management, driving control, and superstructure operation control; the power motor controller and power motor 102 can be used to drive the engineering vehicle 100; the work motor controller and work motor 103 can be used to drive the engineering vehicle 100 for superstructure operations. The vehicle controller 101 can communicate with each power motor controller and each work motor controller via wired or wireless means, and the specific communication method is not limited here. Although not shown in the figure, the engineering vehicle 100 may also include a battery management system and a power battery for energy output and storage. When the power battery of the engineering vehicle 100 proposed in this application is in a high charge state (e.g., SOC exceeds 80%), the electrical energy generated by the braking energy feedback of the power motor 102 can be directly used for the operation consumption of the work motor 103 or the heat consumption of the power motor 102 and the work motor 103, thereby ensuring that braking energy recovery can be performed even when the battery is in a high charge state, thereby solving the problems of reduced total braking force, extended braking distance, and delayed braking response caused by frequent mechanical braking.

[0022] In one embodiment, such as Figure 2 As shown, a braking energy control method is provided, which is applied to... Figure 1 Taking the vehicle controller of an engineering vehicle as an example, the following steps are included: S202, a braking signal is detected, the braking energy to be recovered is obtained, and the battery power is read.

[0023] The vehicle controller can detect braking signals in various ways to identify the timing of regenerative braking. For example, it can acquire brake pedal opening signals in real time via hard-wired signals or the CAN bus, and determine whether a braking signal has been detected based on the opening size. Alternatively, it can determine the detection of a braking signal by detecting changes in the high and low levels of the brake pedal switch. If the braking system is a pneumatic or hydraulic system, the braking signal can be obtained by detecting the air pressure in the brake chamber, the oil pressure in the master cylinder, or the brake valve. If the vehicle uses an electronic braking system, the vehicle controller can consider it a braking signal when it detects a braking request sent by the electronic parking brake module via CAN. If the vehicle is equipped with an autonomous driving system, the vehicle controller can obtain the braking signal by receiving the trigger signal from the automatic emergency braking system, and so on. Alternatively, engineering vehicles can consider a braking signal to be detected when the boom or bucket or other working mechanisms are triggered, and so on.

[0024] The vehicle controller can acquire the braking energy to be recovered in various ways. For example, it can calculate the total braking energy demand based on one or more parameters such as the brake pedal opening, the change in air or oil pressure, the current vehicle speed, and the vehicle mass, and use this as the braking energy to be recovered.

[0025] Meanwhile, the vehicle controller can receive battery SOC data sent by the battery management system via the CAN bus, and then read the current battery level.

[0026] S204, in response to the battery level exceeding a set threshold, sends a request to the work motor controller.

[0027] In this embodiment, when the State of Charge (SOC) exceeds a set threshold, a request can be sent to the work motor controller. This request can be understood as a status request frame, which instructs the work motor controller to feed back the collected operating status of each work motor to the vehicle controller for subsequent work motor status determination. The set threshold can be selected as needed, for example, set to 80%-100%, and the upper and lower limits of this range can be changed to 85%, 90%, 95%, 98%, 99%, etc., as needed.

[0028] S206, Receive status data of each working motor from the working motor controller based on the request feedback.

[0029] The work motor controller can monitor the status data of the work motor in real time, such as speed, current, temperature, and real-time load. When it receives the above request from the vehicle controller, it feeds back the above data and the work motor's operating mode flag to the vehicle controller. The request can be sent via CAN interrupt or polling, whichever is more specific.

[0030] S208, when it is determined from the status data that all working motors are in an idle state, distributes the braking energy to be recovered to each power motor and each working motor, so as to dissipate it through motor heating.

[0031] The vehicle controller can determine the status of each working motor based on status data, such as idle, working, or fault status. Specifically, it can determine the status based on real-time load rate, real-time speed, real-time temperature, and temperature rise rate of the working motor. That is, when the real-time load rate or real-time speed is close to zero or below a corresponding threshold, or the real-time temperature or temperature rise rate is below a certain safety threshold, it can be determined to be in an idle or fault state; otherwise, it is in a working state. Finally, by combining the working mode flag or fault flag, it can eliminate situations where low load, low speed, or low temperature is caused by a fault, thus identifying all working motors in an idle state. The aforementioned thresholds can be set according to the specific type and rated parameters of the working motor.

[0032] In this embodiment, when it is determined that all working motors are idle, the vehicle controller can allocate the braking energy to be recovered to each power motor and each working motor for dissipation through motor heating. In some other embodiments, when it is determined that some working motors are idle and some are in operation, the vehicle controller can prioritize allocating the braking energy to be recovered to the working motors for dissipation through operation, and then allocate the remaining braking energy to each power motor and each idle working motor for dissipation through motor heating; wherein, the remaining braking energy can also be prioritized to each power motor, and finally allocated to the idle working motors. Of course, the above allocation priority can also be adjusted as needed, and there is no limitation here; for example, the braking energy to be recovered can also be prioritized to the working motors and each power motor, and finally allocated to the idle working motors, etc.

[0033] In the above embodiments of this application, the executing entity can be a vehicle controller or other control device with certain computing capabilities, and can be selected and changed according to the actual situation.

[0034] Traditional engineering vehicles brake frequently and with high energy output. When the battery is near full charge, no more energy can be recovered, resulting in energy loss or mechanical braking, leading to significant waste or wear on braking components. The braking energy control method described above addresses this issue by dynamically allocating energy to idle work motors and drive motors when the battery charge is too high to recover braking energy. This actively dissipates excess energy as heat, resolving the conflicting problem of braking energy recovery under high battery conditions. By using motor heat dissipation, the risk of battery overcharging is avoided, reliance on mechanical braking is reduced, and the lifespan of the braking system is extended. Furthermore, by utilizing idle work motors in conjunction with drive motors to dissipate energy, the problem of overheating caused by concentrated loading of a single motor is avoided. The work motors during non-operational periods act as a new energy buffer unit, effectively improving the flexibility of the vehicle's energy system. In addition, the method relies on the cooling circuits inherent in the motors themselves, allowing heat generation to be managed directly through existing systems without the need for additional braking resistors or expanded battery capacity, thus reducing manufacturing costs.

[0035] In one embodiment, the step of the vehicle controller controlling the power motor to dissipate braking energy by heating may specifically include: superimposing periodic positive and negative symmetrical currents into the operating current of the power motor so that its iron core windings heat up and dissipate braking energy; the operating current is used to drive the power motor to output the target braking torque.

[0036] Periodic positive and negative symmetrical current can be understood as a high-frequency balanced alternating current, that is, a current with equal amplitude and opposite polarity in the positive and negative half-cycles. In this embodiment, a specific implementation can be achieved by superimposing a high-frequency sine wave, square wave, or triangular wave carrier wave into the PWM modulation of the motor controller. By adjusting the modulation ratio, periodic positive and negative symmetrical alternating current components are generated and superimposed on the fundamental current (which can be understood as the aforementioned operating current). It is worth noting that the DC component of the superimposed current should be zero to satisfy the symmetry of the positive and negative half-cycles and avoid affecting the target braking torque output of the power motor.

[0037] This method achieves efficient heat dissipation of braking energy by superimposing periodic positive and negative symmetrical currents into the operating current of the power motor. Simultaneously, the active heating of the iron core windings directly dissipates energy, reducing wear on traditional mechanical brakes, extending system life, and lowering maintenance costs. The current superposition design maintains the stability of the motor's output torque, ensuring a smooth and controllable braking process and avoiding the impact of torque fluctuations on the transmission system. Furthermore, this method fully utilizes the resistive characteristics of the motor windings, eliminating the need for additional energy recovery devices, simplifying the system structure, and is particularly suitable for operating conditions where energy recovery is not required under high battery conditions. From a thermal management perspective, the symmetrical alternating current can evenly distribute the heat generated by the windings, avoiding localized overheating and improving heat dissipation efficiency. Overall, this technology achieves synergistic optimization of energy dissipation and braking control through electronic control, combining reliability, economy, and control precision in scenarios involving frequent start-stop operations of engineering vehicles.

[0038] In one embodiment, the step of the vehicle controller controlling the working motor to dissipate braking energy through heating may specifically include: controlling the working motor to output a periodic positive and negative symmetrical current with an average torque of zero, so that its iron core windings heat up and dissipate braking energy. The periodic positive and negative symmetrical current can be found above and will not be repeated here. An average torque of zero can be understood as the working motor not outputting net torque macroscopically under the drive of the periodic positive and negative symmetrical current; however, in reality, instantaneous torque pulsations still exist microscopically.

[0039] It should be noted that if the switching period of the periodic positive and negative symmetrical current output by the working motor is too long, the average torque generated by the motor will not be zero. If the switching period is too short, it will be difficult to control. Therefore, as an optional embodiment, the switching period of the two positive and negative symmetrical currents mentioned above can be set to 0.2ms-1ms. The frequency corresponding to this high-frequency period is 1kHz~5kHz. This frequency band can promote a more uniform distribution of heat on the winding cross-section. At the same time, the eddy currents excited in the iron core by the high-frequency magnetic field will present a more dispersed path. Under short cycles, the heating of the iron core changes from deep penetration to surface dominance. Combined with the stacked design of silicon steel sheets, the heat of the iron core can be diffused laterally evenly. Therefore, setting the switching period within the above range can also effectively prevent local overheating of the motor.

[0040] In some embodiments, the conversion period of the two positive and negative symmetrical currents can also be dynamically adjusted according to the winding temperature of the corresponding motor. The basic adjustment principle is that the higher the temperature, the shorter the conversion period. Faster current commutation can promote heat dissipation inside the winding and help to further avoid local overheating of the working motor.

[0041] As a further optimization, the vehicle controller can also monitor the two positive and negative symmetrical currents mentioned above in real time. If the average torque exceeds a certain threshold for a preset number of consecutive cycles, an alarm can be triggered, or the positive and negative symmetrical currents can be reapplied, or the regenerated braking energy can be redistributed. This measure, by continuously monitoring the symmetry of the positive and negative currents, can quickly identify torque deviations, avoid motor core magnetic saturation / winding overheating damage caused by asymmetrical currents, and improve system reliability.

[0042] In one embodiment, S208 specifically includes: comparing the braking energy to be recovered with a first preset power value; the first preset power value is the sum of the maximum heating power of all power motors and the maximum heating power of all working motors; if the braking energy to be recovered is greater than the first preset power value, then each power motor and each working motor is controlled to heat up at their respective maximum heating power to collaboratively dissipate the braking energy to be recovered. If there is residual braking energy, it can be configured for mechanical dissipation, power battery recovery, or recovery through other equipment in the engineering vehicle, as needed; no limitation is set here.

[0043] It should be noted that the first preset power value is a fixed value, which means that the range of the sum of the maximum heat dissipation power of all power motors and the maximum heat dissipation power of all working motors can be estimated in advance, and a certain value is selected from this range as the first preset power value. More preferably, the first preset power value is a dynamic value, that is, the maximum heat dissipation power of each power motor and each working motor during operation is a dynamic variable, and the actual value is affected by the real-time operating conditions, so it needs to be dynamically calculated or estimated. This scheme can effectively avoid the risk of motor overheating caused by a fixed power preset. Specifically, for example, it can be estimated according to the formula P(t)=(T1-T2(t)) / R, where P(t) is the maximum heat dissipation power of the motor at a certain time t, T1 is the maximum allowable temperature of the motor, T2(t) is the real-time temperature of the motor winding at a certain time t, and R is the thermal resistance.

[0044] Therefore, S208 may further include: obtaining the current maximum heat generation power of all power motors and the current maximum heat generation power of all working motors, summing them, and using the result as the current first preset power value. Then, the braking energy to be recovered is compared with the current first preset power value. If the difference is greater, the braking energy to be recovered can be allocated to each power motor and each working motor according to a weighted ratio, and each motor can generate heat at its maximum heat generation power to collaboratively dissipate the braking energy to be recovered. The aforementioned weighted ratio can be dynamically adjusted based on the current maximum heat generation power of each motor. After allocation, the temperature of each electrode can still be continuously monitored to further dynamically adjust the weighted ratio of power allocation.

[0045] By dynamically comparing the regenerative braking energy with two preset power thresholds (i.e., the first preset power value and the second preset power value), the vehicle controller can intelligently match the optimal energy consumption mode to ensure that the energy is completely dissipated and does not overflow. At the same time, when the regenerative braking energy is greater than the first preset power value, all motors can be mobilized to generate heat at full load to maximize the system's processing capacity.

[0046] In one embodiment, the braking energy control method further includes: determining that the braking energy to be recovered is not greater than a first preset power value and is greater than a second preset power value; the second preset power value is the sum of the maximum heating power of all power motors; controlling each power motor to generate heat at its maximum heating power to dissipate part of the braking energy, and distributing the remaining braking energy to each working motor for dissipation. The second preset power value here can be referred to in the description of the first preset power value above, and can be set as a fixed value, or preferably a dynamic value. The dynamic calculation method for the maximum heating power of the power motors can be referred to the above P(t) calculation process, and will not be elaborated here.

[0047] In this embodiment, when the braking energy to be recovered is between a first preset power value and a second preset power value, the vehicle controller will prioritize the use of the power motor, with the auxiliary motor assisting in energy dissipation. In engineering vehicles, since the power motor is directly connected to the vehicle's drive chain, prioritizing its energy dissipation task avoids potential interference to the vehicle's power output caused by frequent starts and stops of the auxiliary motor. On the other hand, the power motor of engineering vehicles has a strong heat dissipation design, and prioritizing its operation at maximum heat generation power can fully utilize its thermal redundancy. Furthermore, the power motor of engineering vehicles is already in an energy conversion state during braking, compared to the auxiliary motor which needs to start from a standstill. Prioritizing the use of the power motor's heat generation for energy dissipation reduces additional energy path losses. Finally, the allocation mode with the power motor as the main component can effectively reduce the complexity of multi-motor coordinated control and make it easier to achieve dynamic control of braking energy.

[0048] In one embodiment, the braking energy control method further includes: determining that the braking energy to be recovered is not greater than a second preset power value; and distributing the braking energy to be recovered evenly to each power motor for dissipation.

[0049] This solution fully leverages the thermal redundancy potential of multi-motor systems, replacing mechanical braking with electrification to reduce wear and improve braking reliability. Furthermore, the aforementioned hierarchical control logic balances response speed and energy efficiency, avoids overloading of individual motors, achieves temperature equilibrium through dynamic power distribution, and extends motor lifespan. Overall, it achieves efficient, flexible, and safe dissipation of braking energy with minimal hardware cost.

[0050] In one embodiment, the braking energy control method further includes: when it is determined from the state data that a working motor is in operation, the braking energy to be recovered is preferentially allocated to the working motor in operation to dissipate through operation; and the remaining braking energy is allocated to each power motor and the working motor in idle state to dissipate through motor heating.

[0051] For the work motors of engineering vehicles, the cooling system is activated during operation, prioritizing the allocation of regenerative braking energy to the working motors. This avoids the risk of temperature rise caused by starting idle motors, reducing the overall system thermal load and extending motor life. Furthermore, prioritizing energy consumption through mechanical operations by the working motors helps convert braking energy into useful work, such as hydraulic system energy storage or actuator movement. Compared to pure heat dissipation, this significantly improves energy utilization and reduces energy waste. Simultaneously, the working motors are in dynamic operation, and their inertia and control systems can respond to energy allocation commands more quickly.

[0052] In one specific embodiment, this application provides a braking energy control method for a battery in a high-charge state, which is applied to a new energy engineering vehicle equipped with a multi-motor system. The new energy engineering vehicle includes a vehicle controller, a battery management system and a power battery, a power motor controller and a power motor, and a work motor controller and a work motor.

[0053] The operating motor can include two operating modes: a normal operating mode and a zero-torque output mode. The normal operating mode means that the motor operates in the high-efficiency range to convert electrical energy into mechanical energy as efficiently as possible; the zero-torque output mode means that as much electrical energy as possible is consumed through motor heating, and the average torque generated is zero.

[0054] The zero-torque output mode of the motor can be achieved by controlling the motor output with periodic positive and negative symmetrical currents, resulting in zero average output torque but with heat dissipation from the core and windings. The average power of this heat dissipation directly reflects the motor's energy loss efficiency. The vehicle controller can use this parameter to quantify the energy dissipation of the operating motor at zero torque output, aiding in the assessment of the system's thermal management requirements. Specifically, the average power of this heat dissipation can be calculated using the following formula:

[0055] in, R is the equivalent resistance of the iron core and windings, and T is the switching period of the positive and negative symmetrical current.

[0056] Meanwhile, the motor can have two operating modes: a normal operating mode and a target torque output mode. The normal operating mode refers to the motor operating in its high-efficiency range to convert electrical energy into mechanical energy as efficiently as possible. The target torque output mode refers to the motor operating in its low-efficiency range to dissipate as much electrical energy as possible through heating, while still responding to the target torque. The target torque output mode adds periodic positive and negative symmetrical currents to the normal operating current to increase the motor's heating capacity beyond the target torque output. The average heating power can be calculated using the following formula:

[0057] in, The currents are symmetrical, positive and negative. R is the normal current, R is the equivalent resistance of the iron core and windings, and T is the switching period of the positive and negative symmetrical current.

[0058] In this specific embodiment, such as Figure 3 As shown, the braking energy control method may further include: 1. When the vehicle controller detects that the driver has no braking need, there is no need to perform braking energy feedback.

[0059] 2. When the vehicle controller detects that the driver has a braking need and the power battery is not in a high charge state, both the power motor and the work motor are in the above-mentioned normal working mode. The system automatically performs braking energy feedback and stores the recovered electrical energy in the power battery.

[0060] 3. When the vehicle controller detects that the driver has a braking need and the power battery is in a high charge state, it determines whether the working motor is in working state. If the working motor is in working state, the power motor enters the motor heating target torque output mode and the working motor is in normal working mode. The braking energy to be recovered is used for the working motor to consume on the one hand, and consumed through the heat of the power motor on the other hand.

[0061] 4. When the vehicle controller detects that the driver has a braking need and the power battery is in a high charge state, it determines whether the working motor is in working state. If the working motor is not in working state, the power motor enters the motor heating target torque output mode, and the working motor enters the motor heating zero torque output mode, so that the braking energy to be recovered is consumed by the heat of the power motor and the working motor.

[0062] This embodiment is based on the multi-motor system configured in new energy engineering vehicles. By combining the driver's braking needs, the power battery's charge status, and the working status of the work motor, the power motor and the work motor are controlled in a coordinated manner. This enables regenerative braking without adding external hardware, thereby solving the problems of reduced total braking force, increased braking distance, and poor driving experience caused by the inability to regenerate braking energy when the power battery is in a high charge state.

[0063] It should be understood that, for the foregoing method embodiments, although the steps in the flowcharts are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the method embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0064] Based on the same inventive concept, this application also provides a braking energy control device for implementing the braking energy control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more braking energy control device embodiments provided below can be found in the limitations of the braking energy control method described above, and will not be repeated here.

[0065] In one embodiment, such as Figure 4 As shown, a braking energy control device 400 is provided, including: a detection module 401, a request module 402, a receiving module 403, and a control module 404, wherein: The detection module 401 is used to detect the braking signal, acquire the braking energy to be recovered, and read the battery power. Request module 402 is used to send a request to the working motor controller in response to the battery power exceeding a set threshold; The receiving module 403 is used to receive the status data of each working motor from the working motor controller based on the request feedback; The control module 404 is used to distribute the braking energy to be recovered to each power motor and each working motor when it is determined from the status data that each working motor is in an idle state, so as to dissipate it through the motor heating method.

[0066] In one embodiment, the control module 404 is specifically used to superimpose periodic positive and negative symmetrical currents into the operating current of the power motor so that the iron core windings heat up and dissipate braking energy; the operating current is used to drive the power motor to output the target braking torque.

[0067] In one embodiment, the control module 404 is specifically used to control the working motor to output periodic positive and negative symmetrical currents with an average torque of zero, so that the iron core windings heat up and dissipate braking energy.

[0068] In one embodiment, the switching period of the positive and negative symmetrical currents is 0.2ms-1ms.

[0069] In one embodiment, the control module 404 is specifically used to compare the braking energy to be recovered with a first preset power value; the first preset power value is the sum of the maximum heating power of all power motors and the maximum heating power of all working motors; if the braking energy to be recovered is greater than the first preset power value, then each power motor and each working motor is controlled to heat up at their respective maximum heating power to dissipate the braking energy to be recovered in a coordinated manner.

[0070] In one embodiment, the control module 404 is further specifically used to determine that the braking energy to be recovered is not greater than a first preset power value and is greater than a second preset power value; the second preset power value is the sum of the maximum heating power of all power motors; control each power motor to heat up according to its maximum heating power to dissipate part of the braking energy, and distribute the remaining braking energy to each working motor for dissipation.

[0071] In one embodiment, the control module 404 is further specifically used to determine that the braking energy to be recovered is not greater than a second preset power value; and to distribute the braking energy to be recovered evenly to each power motor for dissipation.

[0072] In one embodiment, the control module 404 is further specifically configured to, when it is determined from the state data that a working motor is in a working state, preferentially allocate the braking energy to be recovered to the working motor in the working state so as to dissipate it through operation; and allocate the remaining braking energy to each power motor and the working motor in the idle state so as to dissipate it through motor heating.

[0073] For specific limitations regarding the braking energy control device, please refer to the limitations on the braking energy control method above, which will not be repeated here. Each module in the aforementioned braking energy control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the vehicle controller in hardware form or independently of it, or stored in the memory of the vehicle controller in software form, so that the processor can call and execute the corresponding operations of each module.

[0074] Furthermore, in the above-described embodiment of the braking energy control device, the logical division of each program module is merely illustrative. In practical applications, the above functions can be assigned to different program modules as needed, for example, for the sake of corresponding hardware configuration requirements or the convenience of software implementation. That is, the internal structure of the braking energy control device can be divided into different program modules to complete all or part of the functions described above.

[0075] In one embodiment, an engineering vehicle is also provided, such as Figure 5 As shown, the system includes a vehicle controller, a battery management system, a power battery, at least one power motor, a power motor controller, at least one work motor, and a work motor controller. The vehicle controller communicates with the battery management system, the power motor controller, and the work motor controller, respectively. The power battery is connected to the battery management system, the power motor controller, and the work motor controller, respectively. The vehicle controller detects braking signals, obtains the braking energy to be recovered through the power motor controller, and reads the battery charge of the power battery generated by the battery management system. In response to the battery charge exceeding a set threshold, the vehicle controller sends a request to the work motor controller. The vehicle controller receives the status data of each work motor based on the request. If the status data determines that each work motor is in an idle state, the vehicle controller distributes the braking energy to be recovered to each power motor and each work motor to dissipate it through motor heating.

[0076] In some embodiments, the vehicle controller described above may include a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0077] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0078] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0079] The terms “comprising” and “having”, and any variations thereof, in the embodiments herein are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or (module) units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0080] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A braking energy control method applied to a vehicle controller of an engineering vehicle, the engineering vehicle comprising at least one power motor and at least one work motor, the method comprising: A braking signal is detected, the braking energy to be recovered is acquired, and the battery level is read. In response to the battery level exceeding a set threshold, a request is sent to the working motor controller; Receive the status data of each working motor from the working motor controller based on the request; When it is determined from the state data that all working motors are in an idle state, the braking energy to be recovered is distributed to each power motor and each working motor to dissipate through motor heating.

2. The method according to claim 1, characterized in that, The steps for controlling the power motor to dissipate braking energy through heat generation include: Periodic positive and negative symmetrical currents are superimposed on the operating current of the power motor so that the iron core windings heat up and dissipate braking energy. The operating current is used to drive the power motor to output the target braking torque.

3. The method according to claim 1, characterized in that, The steps for controlling the working motor to dissipate braking energy through heating include: The operating motor is controlled to output a periodic positive and negative symmetrical current with an average torque of zero, so that the iron core windings heat up and dissipate braking energy.

4. The method according to claim 3, characterized in that, The switching period of the positive and negative symmetrical currents is 0.2ms-1ms.

5. The method according to any one of claims 1 to 4, characterized in that, The step of distributing the braking energy to be recovered to each power motor and each working motor for dissipation through motor heating includes: The braking energy to be recovered is compared with a first preset power value; the first preset power value is the sum of the maximum heat generation power of all power motors and the maximum heat generation power of all operating motors. If the braking energy to be recovered is greater than the first preset power value, then each power motor and each working motor are controlled to generate heat at their respective maximum heating power to dissipate the braking energy to be recovered in a coordinated manner.

6. The method according to claim 5, characterized in that, The method further includes: The braking energy to be recovered is determined to be no greater than the first preset power value and greater than the second preset power value; the second preset power value is the sum of the maximum heat generation power of all power motors. Each power motor is controlled to generate heat at its maximum heating power to dissipate part of the braking energy, and the remaining braking energy is distributed to each working motor for dissipation.

7. The method according to claim 6, characterized in that, The method further includes: It is determined that the braking energy to be recovered is not greater than the second preset power value; The braking energy to be recovered is evenly distributed to each power motor for dissipation.

8. The method according to any one of claims 1 to 4, characterized in that, The method further includes: If it is determined from the state data that a working motor is in operation, the braking energy to be recovered is preferentially allocated to the working motor in operation so as to dissipate it through operation. The remaining braking energy is distributed to each power motor and the idle working motor to dissipate through motor heating.

9. A braking energy control device, characterized in that, The device includes: The detection module is used to detect braking signals, acquire the braking energy to be recovered, and read the battery power. The request module is used to send a request to the working motor controller in response to the battery power exceeding a set threshold. The receiving module is used to receive the status data of each working motor fed back by the working motor controller based on the request; The control module is used to distribute the braking energy to be recovered to each power motor and each working motor when it is determined from the status data that each working motor is in an idle state, so as to dissipate it through motor heating.

10. An engineering vehicle, characterized in that, The system includes a vehicle controller, a battery management system, a power battery, at least one power motor, a power motor controller, at least one work motor, and a work motor controller; the vehicle controller communicates with the battery management system, the power motor controller, and the work motor controller, respectively, and the power battery is connected to the battery management system, the power motor controller, and the work motor controller, respectively. The vehicle controller is used to detect braking signals, obtain the braking energy to be recovered through the power motor controller, and read the battery charge of the power battery generated by the battery management system; in response to the battery charge exceeding a set threshold, it sends a request to the working motor controller; receives the status data of each working motor fed back by the working motor controller based on the request; when it is determined based on the status data that each working motor is in an idle state, it distributes the braking energy to be recovered to each power motor and each working motor to dissipate it through motor heating.

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