Precise control method and system of range extender based on multi-working condition prediction and range extended electric vehicle

Abstract

The application discloses a range extender precise control method and system based on multi-working condition prediction and a range extended electric vehicle, S100 acquires front road information and calculates energy prediction information; S200 predicts battery SOC at a road section end point based on the energy prediction information and current battery SOC; S300 inquires a battery charge and discharge characteristic MAP table based on the road section end point battery SOC and current battery temperature to predict battery sustainable discharge power and / or battery sustainable charge power at the road section end point; S400 determines a range extender start-stop flag and power generation power according to control logic corresponding to a current working condition type, wherein the control logic at least includes comparing the battery sustainable charge and discharge power with corresponding road section required motor power to determine the start-stop flag and the power generation power; and S500 outputs a range extender control instruction. The application can finely predict battery capacity at a front road section end point, can adapt to various typical working conditions and can reasonably coordinate multi-working condition conflicts.

Description

Technical Field

[0001] This invention relates to the field of range-extended electric vehicle control technology, specifically a precise control method, system, and range-extended electric vehicle based on multi-condition prediction for range extenders. Background Technology

[0002] Range-extended electric vehicles (REEVs) use an engine + generator + battery + drive motor as their core power architecture. The range extender, consisting of the engine and generator, does not directly drive the vehicle but is used to replenish the battery or directly supply power to the drive motor. The rationality of the range extender control strategy directly affects the vehicle's fuel economy, battery life, and driving smoothness.

[0003] Traditional range extender control methods primarily rely on threshold-triggered control based on the current battery SOC and the real-time vehicle power demand. This means the range extender activates when the battery SOC falls below a set lower limit and deactivates when it rises above a set upper limit. Because this method doesn't anticipate future road conditions, it suffers from control lag. For example, blindly activating the range extender when the vehicle is about to enter a long downhill section can result in insufficient energy recovery and energy waste. Furthermore, frequent start-stop cycles of the range extender exacerbate engine wear and noise.

[0004] To address the aforementioned lag issue, the industry has proposed control methods based on navigation or map information to predict future road conditions, but these methods still have the following shortcomings: First, the decision-making dimension is limited to the state of charge (SOC). For example, the patent application CN116101088A, titled "A Method for Reducing Fuel Consumption of Range-Extended Vehicles, Vehicle Controller, and Storage Medium," determines the vehicle's operating conditions for subsequent journeys based on navigation information and sets different range extender power outputs for flat or uphill sections. However, its control basis is still "whether the remaining battery capacity is within a preset range." However, the actual usable charge and discharge power of a battery varies significantly under different temperatures and SOCs. At the same SOC, the discharge power of a low-temperature battery may be less than 50% of its rated value, while the chargeable power at high SOCs will rapidly decrease. Using SOC alone as the decision-making basis cannot determine whether the battery has sufficient power to meet the motor's power requirements or absorb regenerative energy when the vehicle reaches the end of the road segment. This leads to a mismatch between the range extender's power output and the battery's actual capacity, resulting in battery overcharging, over-discharging, or insufficient motor power.

[0005] Secondly, the prediction accuracy for battery power is insufficient. For example, the "Navigation-Based Range Extender Start-Stop Control Method, Device, Vehicle, and Storage Medium" disclosed in CN117261688A expands the decision-making dimension from state of charge to battery power, calculating and estimating battery discharge power based on current traffic congestion levels, the average battery discharge power over a user-preset historical time period, and correction coefficients, and then controlling the range extender's start accordingly. However, this solution is a statistical estimate of the battery discharge capacity under "current / average operating conditions," and cannot predict the instantaneous continuous charge and discharge capacity of the battery when the vehicle reaches a specific location ahead, especially at road segment transition points. Furthermore, it does not consider the impact of battery temperature on power capacity; in scenarios with large temperature differences in the battery pack at low temperatures, the deviation of the statistical estimate will be significantly amplified.

[0006] Third, the operating condition classification is relatively simplistic and lacks coordination for conflicts between multiple operating conditions. Existing solutions typically only classify operating conditions into two categories: flat roads and uphill sections. They fail to provide refined differentiation and differentiated control for complex and varied actual driving scenarios such as flat-downhill, flat-uphill, uphill, highway, and general-purpose driving. Furthermore, in actual driving, vehicles may simultaneously be in multiple overlapping operating conditions, such as flat-uphill and highway. If there is a lack of reasonable power value rules when power generation commands for various operating conditions are output simultaneously, it will lead to a mismatch between the range extender's power generation and the vehicle's overall demand.

[0007] The information disclosed in the above background section is only intended to enhance the understanding of the overall background of the present invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] To address the aforementioned shortcomings in existing technologies, this invention provides a precise control method, system, and range-extended electric vehicle based on multi-condition prediction. This method can accurately predict the battery capacity at the end of the road segment ahead, adapt to various typical operating conditions, and reasonably coordinate conflicts among multiple operating conditions.

[0009] The technical solution of the present invention is as follows: A precise control method for range extenders based on multi-condition prediction, applied to range-extended electric vehicles, includes: S100: Obtain road information ahead and calculate energy prediction information based on the road information ahead. The energy prediction information includes the required motor power corresponding to different types of road segments ahead and the energy consumed or recyclable energy of the road segment. S200: Based on the energy prediction information and the current battery SOC, predict the battery SOC at the end of the road segment ahead; S300: Based on the battery SOC and current battery temperature at the end of the road segment predicted in step S200, the battery's sustainable discharge power and / or sustainable charging power at the end of the road segment are predicted by querying a pre-established battery charge and discharge characteristic MAP table. S400: Determine the start / stop flag and power generation of the range extender according to the control logic corresponding to the current operating condition type; the control logic includes at least: comparing the battery's sustainable discharge power and / or battery's sustainable charging power with the required motor power of the corresponding road segment in the energy prediction information, and determining the start / stop flag and power generation based on the comparison result; S500: Output range extender control commands based on the result of step S400 to control the operation of the range extender.

[0010] Specifically, step S400 determines the current operating condition type based on the road information ahead and / or the energy prediction information. The operating condition types include flat road-downhill, flat road-uphill, uphill, highway, and general operating conditions. Multiple of these five operating conditions can coexist. When the current road segment is flat and the next road segment is downhill, it is determined to be a flat-downhill driving condition; when the current road segment is flat and the next road segment is uphill, it is determined to be a flat-uphill driving condition; when the current road segment is uphill, it is determined to be an uphill driving condition; when the road grade is expressway, it is determined to be an expressway driving condition; when the minimum motor power required by the vehicle within the future preset distance segment is greater than or equal to the preset economic power generation threshold of the range extender, it is determined to be a general driving condition. When multiple operating conditions among the five operating conditions simultaneously trigger the range extender's power generation command, the maximum absolute value of the power output from the multiple operating conditions is taken as the actual power generation of the range extender.

[0011] Specifically, the energy prediction information includes the required motor power Pm corresponding to different types of road segments ahead, and the energy consumed / recoverable by the road segment E, wherein: The required motor power Pm includes: (1) Motor power required for flat roads; (2) Motor power required for downhill driving; (3) Motor power required for uphill driving; (4) The minimum motor power required for the whole vehicle within the future preset distance range; Consumable / recoverable energy E includes: (5) The energy required to get from the current position to the first downhill section; (6) Energy can be recovered downhill; (7) The energy required to get from the current position to the first uphill section; (8) Energy required to go uphill; The required motor power is positive for discharge and negative for feedback; The energy prediction information is calculated in the following way: S101: Obtain road slope information ahead of the vehicle from the high-precision map via CAN message, and based on the current road segment information, the next road segment information, slope length l, slope α, estimated vehicle weight m, predicted future average vehicle speed v, transmission ratio ig, main reducer ratio i0, transmission system mechanical efficiency ηT, motor efficiency ηm, and tire radius r, calculate the motor power demand Pm and energy consumption E corresponding to the three road segment types of flat road, uphill, and downhill according to the following simultaneous equations, thereby obtaining signals (1), (2), (3), (6), and (8): ; Where Ff is rolling resistance; Fw is air resistance; Fi is slope resistance; Ft is vehicle traction force; Tm is motor torque; nm is motor speed; t is uphill time; g is gravitational acceleration; f is rolling resistance coefficient; Cd is air resistance coefficient; and A is vehicle frontal area. S102: Based on the motor power demand Pm and energy consumption / recoverable energy E corresponding to the three road segment types of flat road, uphill and downhill calculated by S101, and combined with the current road segment information and the next road segment information, signals (4), (5) and (7) are obtained according to the following logic: Minimum required motor power for the vehicle within a preset distance range: provided that the distance to the first road segment ahead is greater than or equal to the preset distance range, if the current road information is flat, then the value is the required motor power for flat roads; if the current road information is uphill, then the value is the required motor power for uphill roads; if the current road information is downhill, then the value is the required motor power for downhill roads; otherwise, the value is 0. Energy required to get from the current location to the first downhill: When the next road segment is downhill, if the current road is flat, its value is the energy required for flat road; if the current road is uphill, its value is the energy required for uphill; if the current road is downhill, its value is the energy that can be recovered downhill; when the next road segment is not downhill, its value is 0. Energy required to get from the current location to the first uphill section: When the next road segment is uphill, if the current road is flat, its value is the energy required for flat road; if the current road is uphill, its value is the energy required for uphill; if the current road is downhill, its value is the energy that can be recovered downhill; when the next road segment is not uphill, its value is 0.

[0012] Specifically, the prediction of battery SOC at the end of the road segment ahead in step S200 includes: For flat-downhill driving conditions, the following formula is used for prediction: SOC at the end of a straight section = Current battery SOC − (Energy required to reach the first downhill section from the current position / Total battery energy) × 100%; SOC at the end of the downhill section = SOC at the end of the straight section + (Recoverable energy on the downhill section / Total battery energy) × 100%; For flat-uphill driving conditions, the following formula is used for prediction: SOC at the end of a straight section = Current battery SOC − (Energy required to reach the first uphill section from the current location / Total battery energy) × 100%; SOC at the end of the uphill section = SOC at the end of the straight section − (energy consumed uphill / total battery energy) × 100%.

[0013] Specifically, in step S300, the sustainable discharge power and / or sustainable charging power of the battery at the end of the road segment ahead is predicted by querying a pre-established battery charge-discharge characteristic MAP table. This includes: The battery charge / discharge characteristic MAP table is queried using the current lowest and highest battery temperatures and the predicted SOC of the battery at the end of the road segment, respectively, to obtain two candidate battery current values. For the discharge scenario, the minimum value of the two candidate battery currents is taken as the battery's continuous discharge current, and for the charging scenario, the maximum value of the two candidate battery currents is taken as the battery's continuous charging current. The obtained battery continuous discharge current or battery continuous charging current is multiplied by the current battery voltage to obtain the battery's sustainable discharge power or battery sustainable charging power at the end of the road segment, respectively.

[0014] Specifically, the control logic for the flat-downhill condition in step S400 includes: The judgment process is initiated when the following preconditions are met simultaneously: ① If the range extender stops generating electricity, the battery's continuous discharge power at the end of the straight road section is greater than or equal to the motor power required on the straight road; ② The current vehicle speed is greater than or equal to the downhill speed threshold on the straight road; ③ The recoverable energy on the downhill section is greater than or equal to the downhill energy threshold on the straight road; ④ The sum of the distance on the straight road and the distance on the downhill section is less than or equal to the downhill distance threshold on the straight road. If all the above prerequisites are met, the range extender shutdown flag is valid if any of the following conditions are met; otherwise, the range extender shutdown flag is invalid: ① If the range extender stops generating electricity, the SOC at the end of the downhill section is greater than or equal to the SOC threshold at the end of the downhill section on flat roads; ② The downhill motor power demand is less than or equal to the predicted battery sustainable charging power at the end of the downhill section.

[0015] Specifically, the control logic for the flat-uphill condition in step S400 includes: The range extender's power generation flag is valid when the following conditions are met simultaneously, where the power generation is the range extender's rated power generation: ① The uphill motor power demand is greater than or equal to the absolute value of the battery's sustainable discharge power at the predicted end of the uphill section minus the range extender's rated power generation; ② The current vehicle speed is greater than or equal to the uphill start speed threshold on flat roads; ③ The current battery SOC is less than or equal to the uphill start SOC threshold on flat roads; ④ The sum of the flat road distance and the uphill distance is less than or equal to the uphill distance threshold on flat roads. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The uphill motor power demand is less than the absolute value of the battery's sustainable discharge power at the predicted end of the uphill section minus the range extender's rated power generation; ② The current vehicle speed is less than the uphill stopping speed threshold on flat roads; ③ The current battery SOC is greater than the uphill stopping SOC threshold on flat roads.

[0016] Specifically, the control logic for the uphill condition, high-speed condition, and general condition in step S400 is as follows: The control logic for the uphill condition includes: The range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the motor power required for uphill driving and the current battery SOC, obtained by querying the pre-calibrated power generation MAP table: ① The motor power required for uphill driving is greater than or equal to the range extender's high-efficiency power generation threshold; ② The current vehicle speed is greater than or equal to the uphill start speed threshold; ③ The current battery SOC is less than or equal to the uphill start SOC threshold; ④ The ratio of uphill distance to planned speed is greater than or equal to the uphill duration threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The current vehicle speed is less than the uphill stop speed threshold; ② The current battery SOC is greater than the uphill stop SOC threshold.

[0017] The control logic for high-speed operation includes: The range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the actual power of the drive motor and the current battery SOC, obtained by querying the pre-calibrated power generation MAP table: ① The road level information is detected as a highway; ② The vehicle speed is greater than or equal to the high-speed start speed threshold within a continuously set time period; ③ The actual power of the drive motor is greater than or equal to the high-speed start power threshold within a continuously set time period; ④ The current battery SOC is less than or equal to the high-speed start SOC threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold. The range extender's power generation flag will be invalidated and the power generation will be 0 when any of the following conditions are met: ① The road grade information is not a highway; ② The vehicle speed is less than the highway stop speed threshold within a continuously set time period; ③ The actual power of the drive motor is less than the highway stop power threshold within a continuously set time period; ④ The current battery SOC is greater than the highway stop SOC threshold; ⑤ The battery peak charging power is greater than the highway stop charging power threshold.

[0018] The control logic for the general operating condition includes: The range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the actual power of the drive motor and the current battery SOC obtained from the pre-calibrated power generation MAP table: ① The minimum motor power required by the vehicle within the future preset distance segment is greater than the range extender's high-efficiency power generation threshold; ② The current vehicle speed is greater than or equal to the general starting speed threshold; ③ The current battery SOC is less than or equal to the general starting SOC threshold; ④ The ratio of the future preset distance segment to the planned vehicle speed is greater than the general duration threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The current vehicle speed is less than the general stop speed threshold; ② The current battery SOC is greater than the general stop SOC threshold.

[0019] This invention also discloses a range extender precision control system based on multi-condition prediction, applied to range-extended electric vehicles, comprising: The data input module is used to collect driver intent information and obtain future road slope information ahead of the vehicle through the in-vehicle T-BOX based on ADAS map and GPS positioning. The PEMS algorithm module is used to receive the driver intention information and the future road slope information from the data input module, and to perform average vehicle speed prediction, energy prediction and rule-based range extender power generation strategy based on the received information, and to execute the range extender precision control method based on multi-condition prediction as described above, and output range extender control commands. The control execution module is used to control the start-up, shutdown, and power generation of the range extender according to the control commands output by the PEMS algorithm module.

[0020] The present invention also discloses a range-extended electric vehicle, including a vehicle controller (VCU), wherein the VCU is used to execute the above-described range extender precision control method based on multi-condition prediction.

[0021] The beneficial effects of this invention are: 1. By obtaining future power and energy demand information from the energy prediction module in advance through the vehicle control unit (VCU), and predicting the battery SOC at the end of the road segment, the range extender start-stop control becomes more proactive, effectively avoiding energy waste caused by traditional lagging threshold control. For example, when the vehicle is about to enter a downhill section, the range extender can be stopped in advance to make full use of downhill energy recovery and significantly improve the overall vehicle energy utilization rate.

[0022] 2. By combining battery temperature, especially dual protection against minimum and maximum temperatures, with the predicted SOC at the end of the route, the system queries the battery's continuous charging MAP and continuous discharging MAP, and determines the battery's actual continuous charging and discharging power based on a strategy of discharging at the minimum value or charging at the maximum value. The range extender output is then adjusted accordingly. This dynamic threshold matching mechanism effectively avoids the risks of overcharging and over-discharging the battery and extends its cycle life.

[0023] 3. This invention designs independent start-stop and power generation control logic for five typical operating conditions: flat road-downhill, flat road-uphill, uphill, highway, and general operating conditions. This solves the problem of poor adaptability of the traditional single threshold method, enabling the range extender to work in the optimal state under various driving scenarios, taking into account both the vehicle's power performance and fuel economy.

[0024] 4. By predicting operating conditions and adjusting dynamic thresholds, the frequent start-stop of the range extender under complex road conditions is significantly reduced, engine wear and noise are reduced, and the NVH performance and driving smoothness of the whole vehicle are improved.

[0025] 5. When multiple operating conditions trigger the range extender's power generation command simultaneously, this invention takes the largest absolute value among the multiple power generation outputs as the final output. This can meet the energy replenishment needs of the most demanding operating conditions, avoid battery over-discharge caused by insufficient power generation, and further improve the precision of energy management. Attached Figure Description

[0026] Figure 1 This is a diagram illustrating the system architecture of a range-extended electric vehicle provided in an embodiment of the present invention. Figure 2 A schematic diagram of a range extender precision control framework based on multi-condition prediction provided in an embodiment of the present invention; Figure 3 A flowchart of a range extender precision control method based on multi-condition prediction provided in an embodiment of the present invention; Figure 4 The judgment logic diagram of the range extender precision control method based on multi-condition prediction provided in the embodiments of the present invention; Figure 5 This is a control logic diagram for flat road-downhill driving conditions provided in an embodiment of the present invention; Figure 6This is a control logic diagram for flat road-uphill driving conditions provided in an embodiment of the present invention; Figure 7 This is a control logic diagram for uphill conditions provided in an embodiment of the present invention; Figure 8 This is a high-speed operating condition control logic diagram provided in an embodiment of the present invention; Figure 9 A general operating condition control logic diagram provided for embodiments of the present invention; Figure 10 This is a schematic diagram of a flat road-downhill working condition provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of a flat road-uphill working condition provided in an embodiment of the present invention; Figure 12 This is a verification diagram of the power generation indicator under uphill conditions provided in an embodiment of the present invention; Figure 13 This is a verification diagram of the high-speed power generation indicator provided in an embodiment of the present invention. Detailed Implementation

[0027] To illustrate the technical content, objectives, and effects of this invention in detail, the following description is provided in conjunction with embodiments and accompanying drawings. In the description of the embodiments, it should be understood that terms indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this embodiment and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Example

[0028] See Figure 1 The multi-condition prediction-based precise control method for range extenders provided in this invention is applied to range-extended electric vehicles, which mainly include three subsystems: Range extender system: The range extender control unit (RCU) coordinates the operation, while the engine control unit (ECU) controls the engine to drive the flywheel integrated starter generator (FISG) to generate electricity. After voltage regulation by the generator control unit (GCU), the electricity is used to replenish the power system or battery. Energy storage system: Centered on the power battery, the battery management system (BMS) monitors the battery's state parameters such as SOC, temperature, voltage, and current in real time, and ensures charging and discharging safety. Powertrain system: The motor control unit (MCU) controls the drive motor (DM), and the transmission control unit (TCU) regulates the torque increase of the mechanical automatic transmission (AMT) to drive the vehicle. The three subsystems mentioned above are centrally controlled by the vehicle control unit (VCU), which integrates operating condition information and decides on energy flow: pure electric mode, range-extended mode, and energy recovery mode. It coordinates the work of each subsystem to achieve an operating mode that is primarily electric drive with range extension and energy replenishment.

[0029] See Figure 2 The multi-condition prediction-based range extender precision control framework of this invention mainly includes a data input module, a PEMS algorithm module, and a control execution module. The data input module contains driver intent information such as accelerator pedal signals, and future road slope information obtained by the onboard T-BOX based on ADAS maps and GPS positioning during vehicle operation. The PEMS algorithm module includes average vehicle speed prediction, energy prediction, and a rule-based range extender power generation strategy. The control execution module includes the range extender system.

[0030] See Figure 3 , Figure 4 The precise control method for range extenders based on multi-condition prediction provided in this embodiment of the invention specifically includes steps S100 to S500.

[0031] Step S100: Obtain road information ahead and calculate energy prediction information based on the road information ahead. The energy prediction information includes the required motor power corresponding to different types of road segments ahead and the energy consumed or recyclable energy of the road segment.

[0032] Specifically, S101: The VCU obtains road slope information (including distance to the first downhill or uphill section, distance to the first road segment, length of the first uphill section, or length of the first downhill section) from the high-precision map via CAN messages, and obtains current road segment information, next road segment information, slope length l, slope α, and flat road length through logical judgment. The current road segment information and next road segment information both include flat road, uphill, or downhill. The slope α is positive when the first road segment ahead is uphill and negative when it is downhill.

[0033] Example of logical judgment for road segment information: When the vehicle starts, if the distance to the first road segment ahead is equal to the distance to the first uphill ahead, then the next road segment information is uphill; otherwise, if the distance to the first road segment ahead is equal to the distance to the first downhill ahead, then the next road segment information is downhill; otherwise, the next road segment information is flat road.

[0034] If the next road segment is a flat road and its distance from the first road segment ahead is not equal to the distance from the first road segment ahead at the previous moment, then the current road segment is a flat road, and its length is equal to the distance from the first road segment ahead. If the distance from the first road segment ahead is detected to be greater than the distance from the first uphill section ahead, then the next road segment is an uphill section, and its length is equal to the distance from the first uphill section ahead. Otherwise, the next road segment is a downhill section, and its length is equal to the distance from the first downhill section ahead. The transitions between other road segments follow the same logic.

[0035] Furthermore, based on the current road segment information, the next road segment information, slope length l, slope α, estimated vehicle weight m, predicted future average vehicle speed v, transmission ratio ig, final drive ratio i0, transmission system mechanical efficiency ηT, motor efficiency ηm, and tire radius r obtained from S101, the following eight signal values ​​are calculated by solving the following simultaneous equations: ① The motor power required for flat roads is electrical power; discharge is positive and feedback is negative. ② The motor power required for downhill driving is electrical power; discharge is positive and feedback is negative. ③ The motor power required for going uphill is electrical power; discharge is positive and feedback is negative. ④ Minimum motor power required for the entire vehicle over the next 1km; ⑤ The energy required to get from the current position to the first downhill section; ⑥ Energy can be recovered downhill; ⑦ The energy required to get from the current location to the first uphill section; ⑧ Energy required to go uphill.

[0036] The specific formulas for the required motor power and energy for each road segment are as follows: 1) Calculate rolling resistance based on vehicle weight, gravitational acceleration, rolling resistance coefficient, and slope. ; 2) Calculate air resistance based on the drag coefficient, the vehicle's frontal area, and average vehicle speed. ; 3) Calculate the slope resistance based on vehicle weight, gravitational acceleration, and gradient. ; 4) Vehicle traction ; 5) Calculate the motor torque based on the vehicle's traction force. ; 6) Calculate the motor speed based on the average vehicle speed and tire radius. ; 7) Calculate the required motor power for each road segment based on motor torque and motor speed. ; 8) Calculate the uphill time based on the slope length and average vehicle speed. ; 9) Calculate the energy consumption of each road segment based on power and time information. ; Where l is the slope length, α is the slope, m is the estimated vehicle weight, v is the predicted future average vehicle speed, ig is the transmission ratio, i0 is the main reducer ratio, ηT is the transmission mechanical efficiency, ηm is the motor efficiency, r is the tire radius, nm is the motor speed; t is the uphill time; g is the gravitational acceleration, f is the rolling resistance coefficient, Cd is the air resistance coefficient, and A is the vehicle's frontal area.

[0037] S102: Based on the required motor power Pm and consumed / recoverable energy E corresponding to the three road segment types of flat road, uphill, and downhill calculated in S101, and combined with the current road segment information and the next road segment information, three signals are obtained according to the following logic: The calculation logic for the minimum motor power required by the vehicle in the next 1km is as follows: Provided the distance to the first road segment ahead is ≥1km, if the current road information is flat, then the minimum motor power required by the vehicle in the next 1km is the motor power required for flat roads; otherwise, if the current road information is uphill, then the minimum motor power required by the vehicle in the next 1km is the motor power required for uphill roads; otherwise, if the current road information is downhill, then the minimum motor power required by the vehicle in the next 1km is the motor power required for downhill roads; otherwise, the minimum motor power required by the vehicle in the next 1km is 0kW.

[0038] The calculation logic for the energy required to get from the current location to the first downhill slope is as follows: If the next road segment is downhill and the current road is flat, then the energy required to get from the current location to the first downhill slope equals the energy required for the flat road; otherwise, if the current road is uphill, then the energy required to get from the current location to the first downhill slope equals the energy required for the uphill slope; otherwise, if the current road is downhill, then the energy required to get from the current location to the first downhill slope equals the recoverable energy of the downhill slope; otherwise, the energy required to get from the current location to the first downhill slope is 0.

[0039] The calculation logic for the energy required to get from the current location to the first uphill section is as follows: If the next road segment is uphill, and the current road is flat, then the energy required to get from the current location to the first uphill section equals the energy required for the flat road; otherwise, if the current road is uphill, then the energy required to get from the current location to the first uphill section equals the energy required for the uphill section; otherwise, if the current road is downhill, then the energy required to get from the current location to the first uphill section equals the recoverable energy for the downhill section; otherwise, the energy required to get from the current location to the first uphill section is 0.

[0040] In summary, the energy prediction information calculated in step S100 includes eight signals, of which signals ①②③⑥⑧ are directly calculated by the equation in S101, and signals ④⑤⑦ are obtained by the derived logic in S102.

[0041] Regarding the execution timing of step S100, the present invention provides the following two implementation methods as non-limiting examples: Implementation Method 1, Parallel Operation: Steps S101 and S102 are continuously executed in the VCU background, continuously calculating the eight signals for all possible road segment types (flat road, uphill, downhill) and storing the calculation results in the VCU buffer. When the subsequent step S400 determines the current operating condition, the control logic directly reads the required signals from the buffer to make a decision. The advantage of this implementation method is that the predicted values ​​can be immediately recalled during the change of operating conditions, and the control response is without delay.

[0042] Implementation Method Two, On-Demand: Step S101 continues to execute in the background. The derived signal calculation in Step S102 and the subsequent prediction calculations in Steps S200 and S300 are only triggered when the VCU identifies a road segment transition ahead, such as an upcoming uphill or downhill section. The advantage of this implementation method is reduced VCU computing resource consumption and decreased MAP lookup frequency.

[0043] Both of the above-described embodiments fall within the protection scope of this invention. Those skilled in the art can choose any embodiment or a combination of both according to specific engineering requirements.

[0044] Step S200: Based on the energy prediction information and the current battery SOC, predict the battery SOC at the end of the road segment ahead. This step adopts a two-stage SOC recursive prediction for flat-downhill and flat-uphill conditions, including predicting the SOC at the end of the straight road segment and the SOC at the end of the uphill / downhill road segment respectively.

[0045] See Figure 10 For flat-to-downhill driving conditions, the VCU predicts the battery SOC using the following formula: SOC at the end of a straight section = Current battery SOC − (Energy required to reach the first downhill section from the current position / Total battery energy) × 100%; SOC at the end of the downhill section = SOC at the end of the straight section + (Recoverable energy on the downhill section / Total battery energy) × 100%; See Figure 11 For flat-to-uphill driving conditions, the VCU predicts the battery SOC using the following formula: SOC at the end of a straight section = Current battery SOC − (Energy required to reach the first uphill section from the current location / Total battery energy) × 100%; SOC at the end of the uphill section = SOC at the end of the straight section − (Energy consumed uphill / Total battery energy) × 100%; The essence of the above two-stage SOC recursive prediction lies in dividing the complete journey "from the current position to the end of the next road segment" into two segments: a straight segment from the current position to the road segment switching point, and a sloping segment from the road segment switching point to the end of the road segment. The impact of each segment on the battery SOC is calculated separately and then recursively predicted. Compared with the existing technology that makes a one-time prediction of the entire energy consumption, the two-stage recursion can capture the changes in battery state before and after the road segment switching more precisely, thus improving the accuracy of SOC prediction.

[0046] Step S300: Based on the battery SOC and current battery temperature predicted at the end of the road segment ahead in step S200, predict the battery's sustainable discharge power and / or battery's sustainable charging power at the end of the road segment ahead by querying the pre-established battery charge and discharge characteristic MAP table.

[0047] This step ignores the effects of battery aging, battery voltage, and transient temperature changes, and uses a dual-temperature lookup table strategy to find the maximum value: (1) Predict the sustainable discharge power of the battery at the end of the straight road section: The battery's lowest and highest temperatures are combined with the predicted SOC at the end of the straight road section to query the pre-calibrated battery continuous discharge MAP table to obtain two candidate discharge currents that are both positive; the minimum value of the two is taken as the battery continuous discharge current; and then multiplied by the current battery voltage to obtain the predicted sustainable discharge power of the battery at the end of the straight road section.

[0048] (2) Predict the sustainable charging power of the battery at the end of the downhill section: The battery's lowest and highest temperatures are combined with the predicted SOC at the end of the downhill section to query the pre-calibrated battery continuous charging MAP table to obtain two candidate charging currents, both of which are negative; the maximum value of the two is taken as the battery continuous charging current; and then multiplied by the current battery voltage to obtain the predicted sustainable charging power of the battery at the end of the downhill section.

[0049] (3) Predict the sustainable discharge power of the battery at the end of the uphill section: Query the pre-calibrated battery continuous discharge MAP table with the current lowest battery temperature and the highest battery temperature combined with the predicted SOC at the end of the uphill section to obtain two candidate discharge currents; take the minimum value of the two as the battery continuous discharge current; and multiply it with the current battery voltage to obtain the predicted sustainable discharge power of the battery at the end of the uphill section.

[0050] The dual-temperature lookup table strategy essentially employs the most conservative battery capability for control decisions, effectively ensuring battery safety. In scenarios with significant temperature differences in low-temperature battery packs, such as winter or prolonged high-load conditions, the internal temperature gradient increases, and the usable power of the lowest-temperature cell is often significantly lower than that of the highest-temperature cell. In such cases, relying solely on the average temperature for table lookup would overestimate the battery's actual usable power capability, potentially leading to overcurrent during discharge or overvoltage during charging. This invention uses a dual-temperature lookup table strategy, taking the minimum value for discharge and the maximum value for charging. This effectively uses the capability of the weakest cell in the battery pack as the overall capability for control, preventing overcurrent in any individual cell.

[0051] The sustainable discharge power and / or sustainable charging power of the battery at the end of the output segment in step S300 are the core basis for the control decision in the subsequent step S400. Unlike the existing technology that makes decisions based solely on SOC, this invention changes the decision dimension from percentage to watts in S300, that is, it directly predicts the actual available power capacity of the battery at the end of the segment and uses this power capacity as the basis for comparison with the motor's power demand, thus enabling the range extender control decision to have a forward-looking power matching capability.

[0052] Step S400: Determine the start / stop flag and power generation of the range extender according to the control logic corresponding to the current operating condition type; the control logic includes at least: comparing the battery's sustainable discharge power and / or battery's sustainable charging power with the required motor power of the corresponding road segment in the energy prediction information, and determining the start / stop flag and power generation based on the comparison result.

[0053] Based on the control logic corresponding to the current operating condition, the start / stop flag and power generation of the range extender are determined. The current operating condition is determined based on the road information ahead and / or the energy prediction information. The operating condition includes flat-downhill, flat-uphill, uphill, highway, and general operating conditions; multiple of these five conditions can coexist. Specific determination rules are as follows: If the current road segment is flat and the next road segment is downhill, then it is determined to be a flat-downhill condition. If the current road segment is flat and the next road segment is uphill, then it is determined to be a flat-uphill condition. If the current road segment information indicates an uphill section, then it is determined to be an uphill driving condition; If the road is classified as a highway, then it is determined to be a highway driving condition; If the minimum motor power required by the vehicle within the preset distance range is greater than or equal to the preset economic power generation threshold of the range extender, it is determined to be a general operating condition.

[0054] Multiple of the five operating conditions can exist simultaneously, each executing its corresponding control logic independently. The design principles and specific rules for the control logic of each operating condition are detailed below.

[0055] Control logic for flat road-downhill conditions, refer to Figure 5 As shown: During downhill driving, the motor can generate regenerative energy to charge the battery. To make full use of this downhill energy recovery, the range extender should be stopped as much as possible during flat-road downhill driving conditions. This will prevent the range extender and the downhill regenerative energy from charging the battery simultaneously, which could cause the battery's SOC to reach its limit too quickly and prevent further downhill energy recovery.

[0056] Under flat-to-downhill conditions, the range extender stop flag is valid if the following prerequisites are met simultaneously, and any one of the following conditions is also met; otherwise, the range extender stop flag is invalid: Prerequisites: ① If the range extender stops generating electricity, the battery's continuous discharge power at the end of the straight road section is greater than or equal to the motor power required on the straight road, meaning the battery is sufficient to independently support the motor power demand on the straight road section without the need for range extender assistance; ② The current vehicle speed is greater than or equal to the downhill speed threshold on the straight road, meaning the vehicle is actually moving, avoiding misjudging parking scenarios; ③ The recoverable energy on the downhill slope is greater than or equal to the downhill energy threshold on the straight road, meaning there is enough downhill energy, making the shutdown decision meaningful; ④ The sum of the straight road distance and the downhill distance is less than or equal to the downhill distance threshold on the straight road, meaning the road conditions ahead are close, resulting in high prediction accuracy.

[0057] Conditions: ① If the range extender stops generating electricity, the SOC at the end of the downhill section is greater than or equal to the SOC threshold at the end of the downhill section on flat roads. That is, after stopping, the battery at the end of the downhill section can still maintain a high SOC, which means that the battery has enough energy and there is no need for the range extender to recharge. ② The downhill motor power demand is less than or equal to the predicted sustainable charging power of the battery at the end of the downhill section. That is, the absolute value of the downhill feedback power does not exceed the charging power that the battery can withstand, and the battery can fully absorb the downhill energy.

[0058] In this embodiment, the downhill speed threshold on flat roads is 1 km / h, the downhill energy threshold on flat roads is 1 kWh, the downhill distance threshold on flat roads is 1 km, and the SOC threshold at the end of the downhill section on flat roads is 60%.

[0059] Control logic for flat road-uphill conditions, refer to Figure 6 As shown: Considering that the rated power of the range extender may not be able to cover the climbing requirements of the high-power drive motor, this invention activates the range extender in advance to charge the battery before the vehicle enters the uphill section, thereby increasing the total vehicle power available during the climbing process.

[0060] Under flat-to-uphill conditions, the range extender's generator activation flag is valid and it will generate electricity at the range extender's rated power when the following conditions are met simultaneously: ① The required motor power for uphill driving is greater than or equal to the absolute value of the battery's sustainable discharge power at the predicted end of the uphill section minus the range extender's rated power generation. This means that the battery's sustainable discharge power alone is insufficient to cover the uphill power requirement, and the range extender needs to provide additional power. ② The current vehicle speed is greater than or equal to the uphill starting speed threshold on flat roads. ③ The current battery SOC is less than or equal to the uphill starting SOC threshold on flat roads, meaning the battery has sufficient charging capacity. ④ The sum of the flat road distance and the uphill distance is less than or equal to the uphill distance threshold on flat roads, indicating that the road conditions ahead are close and the prediction accuracy is high.

[0061] The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The uphill motor power demand is less than the absolute value of the battery's sustainable discharge power at the predicted end of the uphill section minus the range extender's rated power generation; ② The current vehicle speed is less than the uphill stopping speed threshold on flat roads; ③ The current battery SOC is greater than the uphill stopping SOC threshold on flat roads.

[0062] In this embodiment, the starting speed threshold for flat uphill driving is 3 km / h, the stopping speed threshold for flat uphill driving is 1 km / h, the starting SOC threshold for flat uphill driving is 50%, the stopping SOC threshold for flat uphill driving is 70%, and the distance threshold for flat uphill driving is 15 km.

[0063] Uphill operating condition control logic, refer to Figure 7 As shown: The principle is to reduce energy conversion stages. When going uphill, if the range extender operates in its high-efficiency range and directly generates electricity to drive the motor (i.e., direct drive mode), it can avoid the multi-stage energy conversion losses of engine → generator → battery → motor.

[0064] Under uphill conditions, the range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the motor power required for uphill driving and the current battery SOC, obtained by querying the pre-calibrated power generation MAP table: ① The motor power required for uphill driving is greater than or equal to the range extender's high-efficiency power generation threshold; ② The current vehicle speed is greater than or equal to the uphill start speed threshold; ③ The current battery SOC is less than or equal to the uphill start SOC threshold; ④ The ratio of uphill distance to planned speed is greater than or equal to the uphill duration threshold, meaning the uphill duration is long enough for the range extender to start and operate stably; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold.

[0065] The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The current vehicle speed is less than the uphill stop speed threshold; ② The current battery SOC is greater than the uphill stop SOC threshold.

[0066] In this embodiment, the high-efficiency power generation threshold of the range extender is set to 50kW, the uphill start speed threshold is set to 3km / h, the uphill start SOC threshold is set to 50%, the uphill duration threshold is set to 30s, the set battery charging power threshold is set to −50kW, the uphill stop speed threshold is set to 1km / h, and the uphill stop SOC threshold is set to 75%.

[0067] High-speed operating condition control logic, refer to Figure 8 As shown: The principle is to reduce energy conversion. When driving at high speeds, the motor's power demand is stable and relatively high. Allowing the range extender to operate in its high-efficiency range to generate electricity for direct drive can significantly improve the overall vehicle efficiency.

[0068] Under high-speed conditions, the range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the actual power of the drive motor and the current battery SOC obtained by querying the pre-calibrated power generation MAP table: ① The road level information is detected as a highway; ② The vehicle speed is greater than or equal to the high-speed start speed threshold within a continuously set time period; ③ The actual power of the drive motor is greater than or equal to the high-speed start power threshold within a continuously set time period; ④ The current battery SOC is less than or equal to the high-speed start SOC threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold.

[0069] The range extender's power generation flag will be switched to invalid and the power generation power will be 0 when any of the following conditions are met: ① The road level information is not a highway; ② The vehicle speed is less than the highway stop speed threshold within a continuously set time period; ③ The actual power of the drive motor is less than the highway stop power threshold within a continuously set time period; ④ The current battery SOC is greater than the highway stop SOC threshold, and redundancy protection avoids battery overcharging; ⑤ The battery peak charging power is greater than the highway stop charging power threshold.

[0070] In this embodiment, the set time period is 10s, the high-speed start vehicle speed threshold is 40km / h, the high-speed start power threshold is 50kW, the high-speed start SOC threshold is 45%, the high-speed stop vehicle speed threshold is 30km / h, the high-speed stop power threshold is 40kW, the high-speed stop SOC threshold is 70%, and the high-speed stop charging power threshold is −40kW.

[0071] General operating condition control logic, refer to Figure 9 As shown: When the vehicle's power demand is stable within the range extender's high-efficiency range, the range extender generates electricity in the high-efficiency range for direct drive.

[0072] Under general operating conditions, the range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the actual power of the drive motor and the current battery SOC obtained by querying the pre-calibrated power generation MAP table: ① The minimum motor power required by the vehicle within the future preset distance segment is greater than the range extender's high-efficiency power generation threshold; ② The current vehicle speed is greater than or equal to the general starting speed threshold; ③ The current battery SOC is less than or equal to the general starting SOC threshold; ④ The ratio of the future preset distance segment to the planned vehicle speed is greater than the general duration threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold.

[0073] The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The current vehicle speed is less than the general stop speed threshold; ② The current battery SOC is greater than the general stop SOC threshold.

[0074] In this embodiment, the preset distance range is 1km, the general start speed threshold is 1km / h, the general start SOC threshold is 45%, the general duration threshold is 30s, the general stop speed threshold is 1km / h, and the general stop SOC threshold is 65%.

[0075] Multiple of the above five operating conditions can coexist, for example, the vehicle may be simultaneously in a flat-uphill condition and a high-speed condition. When multiple operating conditions trigger the range extender's power generation command simultaneously, this invention adopts the following coordination rule: the maximum absolute value of the power generation output from the multiple operating conditions is taken as the actual power generation of the range extender. The significance of this coordination rule is that the absolute value of the power generation directly determines the rate at which power is supplied to the battery. When multiple operating conditions issue power generation commands but their recommended power is different, taking the one with the largest absolute value means prioritizing the maximum energy replenishment demand among the multiple operating conditions, avoiding continuous discharge of the power battery, excessively rapid drop in SOC, or insufficient vehicle power due to insufficient power generation.

[0076] Step S500: Based on the result of step S400, output range extender control commands to control the operation of the range extender. The output control results include start / stop flags and power generation. The RCU of the range extender system executes operations such as starting, stopping, or generating power at a specified power according to the commands. Example

[0077] To more clearly illustrate the working process and effects of the method described in this invention, a complete application example is given below.

[0078] Step S100: The VCU obtains the following information from the energy prediction module.

[0079] (1) First, the distance to the first downhill section ahead is 4.59km, the distance to the first uphill section ahead is 3.141km, the distance to the first road segment ahead is 3.141km, the length of the first uphill section is 1.449km, and the length of the first downhill section is 1.807km, obtained from the high-precision map via CAN messages. Through logical judgment, it is determined that the current road segment information is flat, the next road segment information is uphill, the uphill length is equal to 1.449km, the downhill length is equal to 0km, and the flat road length is equal to 3.141km. Thus, it can be determined that the current working condition is flat road-uphill.

[0080] (2) According to the vehicle information, the current slope is 0.002, the first uphill slope ahead is 0.034, the first downhill slope ahead is -0.019, the estimated vehicle weight is 13382.94 kg, the predicted future average vehicle speed is 61.8993 km / h, the transmission ratio is 1, the final drive ratio is 5.286, the transmission system mechanical efficiency is 0.95, the motor efficiency is 0.95, and the tire radius is 0.49 m. Based on the above information and the formulas in Section 5, we can calculate: the required motor power on flat roads is 43.7868kW; the required motor power downhill is 0kW; the required motor power uphill is 123.7248kW; the energy required to reach the first downhill from the current location is 0kWh; the recoverable energy downhill is 0kWh; the energy required to reach the first uphill from the current location is 2.2325kWh; the energy required to reach the uphill is 2.8963kWh; the minimum required motor power for the vehicle in the next 1km is 43.7868kW. Step S200: The VCU performs battery SOC prediction based on the information obtained from the energy prediction module.

[0081] The current condition is flat road-uphill. The current battery SOC is 54% and the total battery energy is 51kWh. Therefore, the SOC at the end of the flat road section is 49.6225% and the SOC at the end of the uphill road section is 43.9426%.

[0082] Step S300: Predict the battery's continuous discharge power and continuous charging power. At this time, the lowest battery temperature is 19℃ and the highest battery temperature is 20℃, and the current battery voltage is 630V. The predicted continuous battery discharge power at the end of the straight road section is calculated to be 145.53kW, the predicted continuous battery charging power at the end of the downhill road section is -110.88kW, and the predicted continuous battery discharge power at the end of the uphill road section is 145.53kW.

[0083] Step S400: Calculate the range extender control logic for each operating condition.

[0084] If the current road segment is flat and the next road segment is uphill, and the road classification is expressway, then the current working condition is flat road - uphill and expressway. (1) The current working condition is flat road-uphill. The rated power of the range extender is -150kW. Substituting into the calculation, it can be seen that the conditions for starting the range extender to generate electricity under this working condition are not met. Therefore, the range extender is shut down under this working condition. (2) The start-up flag of the range extender is valid when the current operating condition is high speed. Substituting into the calculation, it can be seen that the range extender does not meet the requirements for high speed operating condition shutdown. At this time, the range extender power generation is -80kW under high speed operating condition.

[0085] Step S500: Output range extender control command.

[0086] In summary: The range extender's start-up and power generation flag is currently valid, and the range extender's power output is -80kW.

[0087] To verify the actual effectiveness of the method of this invention compared with traditional control schemes, comparative tests were conducted on the same vehicle model, the same typical route, and a total mileage of 452 km, using both a VCU-less predictive control scheme and the VCU predictive control scheme of this invention. The test results are as follows.

[0088]

[0089] Therefore, compared with the VCU-less predictive control scheme, the present invention achieves the following savings for the same total mileage: refueling volume is reduced from 97.5L to 93L, saving 4.5L; refueling volume after balancing SOC is reduced from 96.464L to 93.498L, saving 2.966L; actual fuel consumption power generation is increased from 3.938kWh / L to 4.097kWh / L, an increase of approximately 4.04%; and the overall fuel saving rate reaches 3.075%.

[0090] In addition to improving fuel efficiency, simulation and test results also show that the method of the present invention can significantly reduce the number of start-stop cycles of the range extender under complex road conditions, thereby reducing engine wear and noise, improving the overall vehicle NVH performance and driving smoothness; and through the conservative strategy of using dual-temperature MAP lookup table to find the maximum value, the battery is protected from local cell overcurrent in low-temperature scenarios with large temperature differences, thus extending the battery cycle life.

[0091] Furthermore, the verification tests of this invention also show that: (1) When the vehicle is about to enter an uphill road condition, the present invention can start the range extender to generate electricity in advance to provide more power for the vehicle to climb the hill. The power generation of the range extender is optimized according to the predicted power and power demand of the uphill section, so as to improve the climbing power performance; Figure 12 As shown; (2) For example Figure 13As shown, in identifying high-speed, suburban, and urban driving conditions, this invention enables the range extender to operate at its optimal power generation point, with the generated electricity directly used to drive the motor, reducing energy conversion losses. Actual testing and verification show that during normal driving, the system can generally adjust the range extender's power generation according to road conditions, and its functions are normal.

[0092] Although the present invention has been described in detail above with specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A precise control method for range extenders based on multi-condition prediction, applied to range-extended electric vehicles, characterized in that, The method includes: S100: Obtain road information ahead and calculate energy prediction information based on the road information ahead. The energy prediction information includes the required motor power corresponding to different types of road segments ahead and the energy consumed or recyclable energy of the road segment. S200: Based on the energy prediction information and the current battery SOC, predict the battery SOC at the end of the road segment ahead; S300: Based on the battery SOC and current battery temperature at the end of the road segment predicted in step S200, the battery's sustainable discharge power and / or sustainable charging power at the end of the road segment are predicted by querying a pre-established battery charge and discharge characteristic MAP table. S400: Determine the start / stop flag and power generation of the range extender according to the control logic corresponding to the current operating condition type; the control logic includes at least: comparing the battery's sustainable discharge power and / or battery's sustainable charging power with the required motor power of the corresponding road segment in the energy prediction information, and determining the start / stop flag and power generation based on the comparison result; S500: Output range extender control commands based on the result of step S400 to control the operation of the range extender.

2. The precise control method for range extenders based on multi-condition prediction according to claim 1, characterized in that, Step S400: The current operating condition type is determined based on the road information ahead and / or the energy prediction information. The operating condition types include flat road-downhill, flat road-uphill, uphill, highway, and general operating conditions. Multiple of these five operating conditions can coexist. When the current road segment is flat and the next road segment is downhill, it is determined to be a flat-downhill driving condition; when the current road segment is flat and the next road segment is uphill, it is determined to be a flat-uphill driving condition; when the current road segment is uphill, it is determined to be an uphill driving condition; when the road grade is expressway, it is determined to be an expressway driving condition; when the minimum motor power required by the vehicle within the future preset distance segment is greater than or equal to the preset economic power generation threshold of the range extender, it is determined to be a general driving condition. When multiple operating conditions among the five operating conditions simultaneously trigger the range extender's power generation command, the maximum absolute value of the power output from the multiple operating conditions is taken as the actual power generation of the range extender.

3. The precise control method for range extenders based on multi-condition prediction according to claim 2, characterized in that, The energy prediction information includes the required motor power Pm corresponding to different types of road sections ahead, and the energy consumed / recoverable by the road section E, wherein: The required motor power Pm includes: (1) Motor power required for flat roads; (2) Motor power required for downhill driving; (3) Motor power required for uphill driving; (4) The minimum motor power required for the whole vehicle within the future preset distance range; Consumable / recoverable energy E includes: (5) The energy required to get from the current position to the first downhill section; (6) Energy can be recovered downhill; (7) The energy required to get from the current position to the first uphill section; (8) Energy required to go uphill; The required motor power is positive for discharge and negative for feedback; The energy prediction information is calculated in the following way: S101: Obtain road slope information ahead of the vehicle from the high-precision map via CAN message, and based on the current road segment information, the next road segment information, slope length l, slope α, estimated vehicle weight m, predicted future average vehicle speed v, transmission ratio ig, main reducer ratio i0, transmission system mechanical efficiency ηT, motor efficiency ηm, and tire radius r, calculate the motor power demand Pm and energy consumption E corresponding to the three road segment types of flat road, uphill, and downhill according to the following simultaneous equations, thereby obtaining signals (1), (2), (3), (6), and (8): ； Where Ff is rolling resistance; Fw is air resistance; Fi is slope resistance; Ft is vehicle traction force; Tm is motor torque; nm is motor speed; t is uphill time; g is gravitational acceleration; f is rolling resistance coefficient; Cd is air resistance coefficient; and A is vehicle frontal area. S102: Based on the motor power demand Pm and energy consumption / recoverable energy E corresponding to the three road segment types of flat road, uphill and downhill calculated by S101, and combined with the current road segment information and the next road segment information, signals (4), (5) and (7) are obtained according to the following logic: Minimum required motor power for the vehicle within a preset distance range: provided that the distance to the first road segment ahead is greater than or equal to the preset distance range, if the current road information is flat, then the value is the required motor power for flat roads; if the current road information is uphill, then the value is the required motor power for uphill roads; if the current road information is downhill, then the value is the required motor power for downhill roads; otherwise, the value is 0. Energy required to get from the current location to the first downhill: When the next road segment is downhill, if the current road is flat, its value is the energy required for flat road; if the current road is uphill, its value is the energy required for uphill; if the current road is downhill, its value is the energy that can be recovered downhill; when the next road segment is not downhill, its value is 0. Energy required to get from the current location to the first uphill section: When the next road segment is uphill, if the current road is flat, its value is the energy required for flat road; if the current road is uphill, its value is the energy required for uphill; if the current road is downhill, its value is the energy that can be recovered downhill; when the next road segment is not uphill, its value is 0.

4. The precise control method for range extenders based on multi-condition prediction according to claim 3, characterized in that, Step S200, which predicts the battery SOC at the end of the road segment ahead, specifically includes: For flat-downhill driving conditions, the following formula is used for prediction: SOC at the end of a straight section = Current battery SOC − (Energy required to reach the first downhill section from the current position / Total battery energy) × 100%; SOC at the end of the downhill section = SOC at the end of the straight section + (Recoverable energy on the downhill section / Total battery energy) × 100%; For flat-uphill driving conditions, the following formula is used for prediction: SOC at the end of a straight section = current battery SOC − (energy consumed from the current position to the first uphill / total battery energy) × 100%; SOC at the end of the uphill section = SOC at the end of the straight section − (energy consumed uphill / total battery energy) × 100%.

5. The precise control method for range extenders based on multi-condition prediction according to claim 1 or 4, characterized in that, Step S300 involves querying a pre-established battery charge / discharge characteristic MAP table to predict the battery's sustainable discharge power and / or sustainable charging power at the end of the upcoming road segment. Specifically, this includes: The battery charge / discharge characteristic MAP table is queried using the current lowest and highest battery temperatures and the predicted SOC of the battery at the end of the road segment, respectively, to obtain two candidate battery current values. For the discharge scenario, the minimum value of the two candidate battery currents is taken as the battery's continuous discharge current, and for the charging scenario, the maximum value of the two candidate battery currents is taken as the battery's continuous charging current. The obtained battery continuous discharge current or battery continuous charging current is multiplied by the current battery voltage to obtain the battery's sustainable discharge power or battery sustainable charging power at the end of the road segment, respectively.

6. The precise control method for range extenders based on multi-condition prediction according to claim 5, characterized in that, The control logic for the flat-downhill condition in step S400 includes: The judgment process is initiated when the following preconditions are met simultaneously: ① If the range extender stops generating electricity, the battery's continuous discharge power at the end of the straight road section is greater than or equal to the motor power required on the straight road; ② The current vehicle speed is greater than or equal to the downhill speed threshold on the straight road; ③ The recoverable energy on the downhill section is greater than or equal to the downhill energy threshold on the straight road; ④ The sum of the distance on the straight road and the distance on the downhill section is less than or equal to the downhill distance threshold on the straight road. If all the above prerequisites are met, the range extender shutdown flag is valid if any of the following conditions are met; otherwise, the range extender shutdown flag is invalid: ① If the range extender stops generating electricity, the SOC at the end of the downhill section is greater than or equal to the SOC threshold at the end of the downhill section on flat roads; ② The downhill motor power demand is less than or equal to the predicted battery sustainable charging power at the end of the downhill section.

7. The precise control method for range extenders based on multi-condition prediction according to claim 5, characterized in that, The control logic for the flat-uphill condition in step S400 includes: The range extender's power generation flag is valid when the following conditions are met simultaneously, where the power generation is the range extender's rated power generation: ① The uphill motor power demand is greater than or equal to the absolute value of the battery's sustainable discharge power at the predicted end of the uphill section minus the range extender's rated power generation; ② The current vehicle speed is greater than or equal to the uphill start speed threshold on flat roads; ③ The current battery SOC is less than or equal to the uphill start SOC threshold on flat roads; ④ The sum of the flat road distance and the uphill distance is less than or equal to the uphill distance threshold on flat roads. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The uphill motor power demand is less than the absolute value of the battery's sustainable discharge power at the predicted end of the uphill section minus the range extender's rated power generation; ② The current vehicle speed is less than the uphill stopping speed threshold on flat roads; ③ The current battery SOC is greater than the uphill stopping SOC threshold on flat roads.

8. The precise control method for range extenders based on multi-condition prediction according to claim 5, characterized in that, The control logic for the uphill condition, high-speed condition, and general condition in step S400 is as follows: The control logic for the uphill condition includes: The range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the motor power required for uphill driving and the current battery SOC, obtained by querying the pre-calibrated power generation MAP table: ① The motor power required for uphill driving is greater than or equal to the range extender's high-efficiency power generation threshold; ② The current vehicle speed is greater than or equal to the uphill start speed threshold; ③ The current battery SOC is less than or equal to the uphill start SOC threshold; ④ The ratio of uphill distance to planned speed is greater than or equal to the uphill duration threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The current vehicle speed is less than the uphill stop speed threshold; ② The current battery SOC is greater than the uphill stop SOC threshold. The control logic for high-speed operation includes: The range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the actual power of the drive motor and the current battery SOC, obtained by querying the pre-calibrated power generation MAP table: ① The road level information is detected as a highway; ② The vehicle speed is greater than or equal to the high-speed start speed threshold within a continuously set time period; ③ The actual power of the drive motor is greater than or equal to the high-speed start power threshold within a continuously set time period; ④ The current battery SOC is less than or equal to the high-speed start SOC threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The road level information is not a highway; ② The vehicle speed is less than the highway stop speed threshold within a continuously set time period; ③ The actual power of the drive motor is less than the highway stop power threshold within a continuously set time period; ④ The current battery SOC is greater than the highway stop SOC threshold; ⑤ The battery peak charging power is greater than the highway stop charging power threshold. The control logic for the general operating condition includes: The range extender's power generation flag is valid when the following conditions are met simultaneously. The range extender generates power based on the actual power of the drive motor and the current battery SOC obtained from the pre-calibrated power generation MAP table: ① The minimum motor power required by the vehicle within the future preset distance segment is greater than the range extender's high-efficiency power generation threshold; ② The current vehicle speed is greater than or equal to the general starting speed threshold; ③ The current battery SOC is less than or equal to the general starting SOC threshold; ④ The ratio of the future preset distance segment to the planned vehicle speed is greater than the general duration threshold; ⑤ The battery peak charging power is less than or equal to the set battery charging power threshold. The range extender power generation flag is switched to invalid and the power generation is 0 when any of the following conditions are met: ① The current vehicle speed is less than the general stop speed threshold; ② The current battery SOC is greater than the general stop SOC threshold.

9. A precision control system for range extenders based on multi-condition prediction, applied to range-extended electric vehicles, characterized in that, include: The data input module is used to collect driver intent information and obtain future road slope information ahead of the vehicle through the in-vehicle T-BOX based on ADAS map and GPS positioning. The PEMS algorithm module is used to receive the driver intention information and the future road slope information from the data input module, and to perform average vehicle speed prediction, energy prediction and rule-based range extender power generation strategy based on the received information, and to execute the range extender precision control method based on multi-condition prediction as described in any one of claims 1 to 8, and output range extender control commands. The control execution module is used to control the start-up, shutdown, and power generation of the range extender according to the control commands output by the PEMS algorithm module.

10. A range-extended electric vehicle, characterized in that, It includes a vehicle control unit (VCU) for executing the range extender precision control method based on multi-condition prediction as described in any one of claims 1 to 8.

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