Vehicle single limit working condition target power calculation method based on wide-area working condition classification

Abstract

The invention relates to a vehicle single limit condition target power calculation method based on wide-area condition classification, and the method comprises the steps: obtaining parameters through a built-in sensor of a vehicle-mounted power unit, the vehicle working condition is divided into a low-temperature single limit working condition, a high-temperature single limit working condition or a high-altitude single limit working condition based on parameter judgment; according to the method, the required torque TR and the actual rotating speed na of an engine or a generator serve as basic parameters, adaptive power correction values and interval adjustment parameters are introduced according to different working conditions, a calculation model of the target required output power PO is built by combining power system characteristics, and therefore the target required output power PO of the vehicle is obtained; and self-adaptive matching and stable output of vehicle power under a single limit working condition are realized.

Description

A method for calculating the target power of a vehicle under a single extreme operating condition based on wide-range operating condition classification Technical Field

[0001] This invention relates to the field of vehicle powertrain control technology, and specifically to a method for calculating the target power of a vehicle under a single extreme operating condition. Background Technology

[0002] When unmanned platforms operate autonomously in complex environments, their power systems need to dynamically adjust their states according to the external environment to adapt to the system performance requirements and practical application needs in different scenarios. The external environment is characterized by significant randomness, extremes, and complexity, and the degree of environmental extremes and multi-environment coupling directly imposes stringent requirements on the stable output characteristics of the power system. Actual vehicle power systems need to meet the usage requirements under extreme conditions, but do not need to maintain high-specification power output and performance redundancy in all environments. Therefore, the core technical challenges lie in: how to determine the system state and select strategies based on real-time environmental parameters under drastic environmental changes, achieving dynamic matching of its own performance to ensure stable and effective power system output; and how to achieve precise matching of the power system state to environmental changes, which is crucial for improving the energy utilization rate of the vehicle's power unit and realizing modular integrated control of the system. Existing technologies are insufficient to meet the adaptive operation requirements of unmanned platforms in complex and ever-changing environments. Therefore, a vehicle parameter matching and power calculation technology adaptable to a wide range of operating conditions is urgently needed to solve the aforementioned technical bottlenecks. Summary of the Invention

[0003] In view of this, this invention proposes a target power calculation method for a vehicle under a single extreme operating condition based on a wide-range operating condition classification. Addressing the environmental adaptability requirements of unmanned vehicles, this method, based on the characteristics of the intelligent system itself and relevant state parameters, performs characteristic analysis of different operating conditions within a wide range, thereby rationally calculating the target power. By accurately identifying operating condition differences and combining them with system performance matching results, control commands are effectively issued to change the actual output characteristics of the system, thus meeting the functional requirements and performance indicators in complex environments. The specific technical solution is as follows: A target power calculation method for a vehicle under a single extreme operating condition based on a wide-range operating condition classification, using parameters acquired by built-in sensors in the vehicle's power unit, including ambient temperature t and altitude h. Based on these parameters, the vehicle operating condition is classified into low-temperature single extreme operating condition, high-temperature single extreme operating condition, or high-altitude single extreme operating condition; the required torque T is used as the basis for the calculation. R The actual speed n of the engine or generator a Based on the fundamental parameters, appropriate power correction values ​​and range adjustment parameters are introduced for different operating conditions, and the target required output power P is constructed by combining the characteristics of the power system. O The calculation model is used to obtain the target required output power P of the vehicle. OThis enables adaptive matching and stable output of vehicle power under single extreme operating conditions.

[0004] Furthermore, the environmental boundaries of the low-temperature single extreme condition are: ambient temperature within the range of [-50℃, 0℃), and altitude less than 3000m; the power correction value is the low-temperature system loss power correction value κ. 11 The range adjustment parameter is the low temperature range adjustment parameter n. 11 Target output power P O via κ 11 With n 11 A computational model is constructed; under a single extreme low-temperature operating condition, the target required output power is greater than the system's rated power to provide additional operating heat; the power loss correction value κ of the low-temperature system is described. 11 The calculation formula is as follows:

[0005] The low temperature range adjustment parameter n 11 The calculation formula is as follows:

[0006] Where κ2 is the engine or generator speed correction value corresponding to the air pressure under normal operating conditions, and the target required output power P O The calculation model is as follows:

[0007] .

[0008] Furthermore, the environmental boundaries of the high-temperature single extreme condition are: the ambient temperature is within the range of (40℃, 120℃), and the altitude is less than 3000m; the power correction value is the high-temperature system loss power correction value κ. 12 The range adjustment parameter is the high temperature range adjustment parameter n. 12 Target output power P O via κ 12 With n 12 Construct a computational model; under high-temperature single extreme operating conditions, the target required output power is less than the system rated power to meet the protection requirements of adapter components and reduce power output efficiency loss; the high-temperature system loss power correction value κ 12 The calculation formula is as follows:

[0009] The high temperature range adjustment parameter n 12 The calculation formula is as follows:

[0010] Where κ2 is the engine or generator speed correction value corresponding to the air pressure under normal operating conditions, and the target required output power P O The calculation model is as follows:

[0011] .

[0012] Furthermore, the environmental boundaries of the high-altitude single extreme condition are: ambient temperature within the range of [0℃, 40℃], and altitude greater than 3000m; under the high-altitude single extreme condition, the atmospheric pressure P ac The power correction value varies non-linearly with altitude h, and the power correction value is the engine or generator speed correction value κ corresponding to the high altitude air pressure. 21 The interval adjustment parameter is the high-altitude interval adjustment parameter n. 21 The κ 21 The calculation formula is as follows: Among them, the pressure ratio , The standard atmospheric pressure at zero altitude, n 21 The calculation formula is as follows:

[0013]

[0014] κ1 represents the power correction value corresponding to system losses under different temperature conditions during normal operation, and the target required output power P is... O The calculation model is as follows: .

[0016] Furthermore, the method is applicable to power systems consisting of an engine and a generator, wherein the engine and generator are directly connected and have approximately equal rotational speeds.

[0017] Beneficial Effects 1. Precise Adaptation to Single Extreme Scenarios, Solving the Problem of Targeted Matching: This invention specifically designs a target power calculation scheme for the characteristics of single extreme operating conditions (low temperature, high temperature, high altitude, etc.), overcoming the limitation of existing technologies that lack scenario-specificity. By focusing on the core influencing factors of a single extreme environment (air pressure changes at low temperature, high temperature, and high altitude), and combining the characteristics of the intelligent system itself with real-time status parameters, it achieves precise adaptation to single extreme operating conditions, effectively solving the technical pain point of mismatch between power output and demand of unmanned platforms in extreme environments.

[0018] 2. Optimize power output and energy utilization to reduce redundant losses: This method, based on the environmental characteristics and system performance matching results of a single extreme operating condition, rationally calculates the target power, avoiding the "one-size-fits-all" high-power redundant output mode in traditional technologies. While meeting the stable output requirements of the power system under a single extreme environment, it minimizes unnecessary energy losses, significantly improves the energy utilization rate of the vehicle's power unit, provides support for the long-term autonomous operation of the unmanned platform under a single extreme operating condition, and facilitates the realization of modular integrated control of the system.

[0019] 3. Connecting to a Wide-Range Operating Condition System, Strengthening the Foundation for Full-Condition Adaptability: As a core component of wide-range operating condition vehicle parameter matching technology, this invention's precise power calculation logic for a single extreme operating condition not only fills the gap in existing technologies' adaptability to single extreme scenarios but also forms a logical connection and technological complementarity with normal operating conditions and extreme coupled operating conditions. By clarifying the parameter matching rules for a single extreme operating condition, it provides reliable technical support for full-scenario adaptive adjustment under wide-range operating conditions, further improving the overall adaptability and operational stability of unmanned platforms in the face of complex and ever-changing environments. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the method described in this invention; Figure 2 is a schematic diagram of the vehicle target parameter demand matching and target power calculation process based on full-condition classification. Detailed Implementation

[0021] For a power system composed of an engine and generator, the actual operating conditions of a vehicle are closely related to the operating conditions of the system. Under different operating conditions, the vehicle's characteristics differ. Regarding the vehicle's output power, the two most important factors affecting it are the external ambient temperature and air pressure. When the vehicle's external environment changes, the system needs to accurately calculate the target power demand based on the changes in operating conditions and transmit the target power value to the engine and motor controllers, thereby adjusting its own characteristics to meet the system's adaptability and stable power output under different conditions.

[0022] The wide-range operating conditions specifically encompass three scenarios in the actual operation of unmanned platforms: normal operating conditions, single extreme operating conditions, and extreme coupled operating conditions. These three types of operating conditions are not independent but exhibit significant correlation and a progressive analytical relationship. Based on the parameter matching logic of normal operating conditions, targeted optimization is performed by considering the characteristic differences of single extreme operating conditions (such as low temperature, high temperature, and high altitude). Furthermore, the coupled calculation logic for extreme coupled operating conditions is formed by superimposing dual extreme factors, thus realizing the construction of an operating condition adaptation system from basic to complex and from single to multiple. The following will, with reference to Figures 1 and 2, begin by explaining the target power calculation logic and implementation process under normal operating conditions, and then elaborate on the subsequent single extreme operating conditions and extreme coupled operating conditions, ultimately presenting a complete and accurate matching scheme for the power system under the wide-range operating conditions.

[0023] Step 1: Calculation of Target Power under Normal Operating Conditions. During actual vehicle operation, a reasonable target output power value needs to be calculated based on actual environmental changes to ensure accurate issuance of control commands. The normal operating environment for the system is a temperature range of [0℃, 40℃] and an altitude range of [-500m, 3000m]. The temperature and altitude data used in the calculation process can be obtained from sensor data within the onboard power unit.

[0024] 1.1 Calculation of System Output Power Requirements Under normal vehicle conditions, the engine and generator are directly connected, therefore their speeds are approximately equal. At this time, the target output power requirement P of the power system is... O The corresponding calculation method is as follows:

[0025] In the formula, T R For the required torque, n a κ1 represents the actual engine / generator speed, κ2 represents the power correction value corresponding to system losses under different temperature conditions, and κ3 represents the engine speed correction value corresponding to pressure changes under different air pressure conditions.

[0026] 1.2 Variable Temperature Output Power Correction Calculation Considering the influence and changes in ambient temperature, there is a difference between the actual required output power of the system and the target output power. Therefore, κ1 is adaptively calculated according to the state changes in the normal temperature range to achieve the correction setting of the target power. Under normal temperature conditions, κ1 needs to be matched and calculated according to the ambient temperature.

[0027] As the ambient temperature t gradually increases within the range of [0℃, 40℃], heat loss is relatively small. Under these conditions, the system output power increases with rising temperature, allowing it to output power greater than the rated power. Considering the system's own losses, the power correction value κ1 at this point is:

[0028] 1.3 Calculation of Output Power Correction Based on Altitude The nonlinear variation of atmospheric pressure needs to be considered depending on the actual altitude. Assume the standard atmospheric pressure at 0 altitude is P. v (kPa), pressure P at altitudes below 3000m ac It changes approximately linearly with altitude h (m), as shown below:

[0029] Considering the influence and changes in the external environment, there is a difference between the actual required output power and the target output power of the system. Therefore, κ2 is adaptively calculated based on state changes under normal altitude conditions to correct the target power setting. Under normal temperature conditions, κ2 needs to be matched and calculated according to the external altitude.

[0030] At different altitudes, the power correction value κ2 is:

[0031] Step 2: Calculation of power demand under temperature differences. When the vehicle is in an ambient temperature range of [-50℃, 0℃] and (40℃, 120℃) and an altitude of less than 3000m, the power system needs to perform power demand matching calculations based on the actual system state in order to achieve system performance matching under different operating conditions.

[0032] 2.1 Calculation of Power Requirement in Low-Temperature Environments When the system is in a low-temperature environment, i.e., the ambient temperature is within the range of [-50℃, 0℃) or even lower, the target output power requirement P of the power system is calculated. O The corresponding calculation method is as follows:

[0033]

[0034] In the formula, κ 11 n represents the power correction value corresponding to system losses under low-temperature conditions. 11 The adjustment parameters for the low-temperature range are calculated as follows:

[0035] κ2 is the power correction value in 1.3.

[0036] Under different low-temperature environments, the power system itself requires a certain amount of heat to operate. Under extreme low-temperature conditions, the system power output may be temporarily suspended. However, under normal low-temperature conditions, the target power demand of the system should be greater than the rated power required for actual system operation to provide the additional heat needed for system operation. Therefore:

[0037] 2.2 Calculation of Power Requirement in High-Temperature Environments When the system is in a high-temperature environment, i.e., the ambient temperature is within the range of (40℃, 120℃) or even higher, the target output power P required by the power system is calculated. O The corresponding calculation method is as follows:

[0038]

[0039] In the formula, κ2 is the power correction value in 1.3, κ 12 n represents the power correction value corresponding to system losses under high-temperature conditions. 12 The adjustment parameters for the high-temperature range are calculated as follows:

[0040] Under different high-temperature environments, the system power output efficiency will decrease due to the protection of its own components. However, under normal high-temperature conditions, the target power requirement of the system should be less than the rated power required for actual system operation. Therefore:

[0041] Step 3: Calculation of Power Demand under Pressure Differences. Based on the linear relationship between atmospheric pressure and altitude, when the altitude is greater than 3000m, the relationship between atmospheric pressure and altitude h becomes non-linear. Considering the pressure variation characteristics of high-altitude areas, the specific corresponding actual atmospheric pressure P... ac The relationship between altitude h and altitude is as follows:

[0042] Considering a single extreme environmental change, namely when the vehicle is in an ambient temperature range of [0℃, 40℃] and the altitude is greater than 3000m, the power system needs to perform power demand matching calculations based on the actual altitude to achieve system performance matching under different operating conditions.

[0043] At this point, considering nonlinear air pressure changes, the target required output power P of the power system is... O The corresponding calculation method is as follows:

[0044]

[0045] Wherein, κ1 is the power correction value in 1.2.

[0046] κ 21 n represents the engine speed correction value corresponding to pressure changes under different high-altitude air pressure conditions. 21 These are the adjustment parameters corresponding to the high-altitude range.

[0047] When the altitude is greater than 3000m, the pressure ratio λ < 0.6. As the altitude increases, the pressure ratio λ gradually decreases, at which point the engine speed correction value κ... 21 The corresponding calculation method is as follows:

[0048] Considering the difference in the changes of the two parameters within this range, the adjustment parameter n... 21 The corresponding calculation method is as follows:

[0049] Step 4: Calculation of Power Demand under Coupled Operating Conditions. When the vehicle is in an ambient temperature range of [-50℃, 0℃] or (40℃, 120℃) and the altitude is greater than 3000m, the operating environment is considered a limit-coupled state. Under this condition, the calculation of the target power demand needs to consider the influence of different factors under coupled operating conditions. The powertrain system needs to perform corresponding target power demand calculations to achieve system performance matching under special operating conditions.

[0050] 4.1 Power Calculation under Low-Temperature Coupling Conditions Under low-temperature conditions, both ambient temperature and altitude are at extreme limits beyond normal operating conditions. It is necessary to calculate the temperature and altitude correction coefficients χ under these extreme coupling conditions. lt Based on the dynamic differences in temperature and altitude, the calculation methods for different conditions are as follows:

[0051] Among them, κ 11 κ represents the power correction value corresponding to system losses under low-temperature conditions as described in section 2.1. 21 This refers to the engine speed correction values ​​corresponding to pressure changes under different high-altitude air pressure conditions in step three. At this point, the target required output power P of the power system is... O The corresponding calculation methods are coupled, and the corresponding calculation methods are as follows:

[0052] In the formula, κ lt The low-temperature compensation coefficient is calculated as follows:

[0053] 4.2 Power Calculation under High-Temperature Coupling Conditions Under high-temperature conditions, both ambient temperature and altitude are at extreme limits beyond normal operating conditions. It is necessary to calculate the temperature and altitude correction coefficients χ under these extreme coupling conditions. ht Based on the dynamic differences in temperature and altitude, the calculation methods for different conditions are as follows:

[0054] Among them, κ 12 κ represents the power correction value for system losses under low-temperature conditions as described in section 2.2. 21 This refers to the engine speed correction values ​​corresponding to pressure changes under different high-altitude air pressure conditions in step three. At this point, the target required output power P of the power system is... O The corresponding calculation methods are coupled, and the corresponding calculation methods are as follows:

[0055] In the formula, κ ht The high-temperature optimization coefficient is calculated as follows: .

Claims

1. A method for calculating the target power of a vehicle under a single extreme operating condition based on wide-range operating condition classification, characterized in that, The parameters are obtained by the built-in sensors of the vehicle power unit, including ambient temperature t and altitude h. Based on the parameters, the vehicle operating conditions are divided into low temperature single extreme condition, high temperature single extreme condition or high altitude single extreme condition. Based on the required torque T R The actual speed n of the engine or generator a Based on the fundamental parameters, appropriate power correction values ​​and range adjustment parameters are introduced for different operating conditions, and the target required output power P is constructed by combining the characteristics of the power system. O The calculation model is used to obtain the target required output power P of the vehicle. O This enables adaptive matching and stable output of vehicle power under single extreme operating conditions.

2. The method according to claim 1, characterized in that, The environmental boundary for the specific low-temperature single extreme condition is: the ambient temperature is within the range of [-50℃, 0℃), and the altitude is less than 3000m; the power correction value is the low-temperature system loss power correction value κ. 11 The range adjustment parameter is the low temperature range adjustment parameter n. 11 Target output power P O via κ 11 With n 11 A computational model is constructed; under a single extreme low-temperature operating condition, the target required output power is greater than the system's rated power to provide additional operating heat; the power loss correction value κ of the low-temperature system is described. 11 The calculation formula is as follows: The low temperature range adjustment parameter n 11 The calculation formula is as follows: Where κ2 is the engine or generator speed correction value corresponding to the air pressure under normal operating conditions, and the target required output power P O The calculation model is as follows: 。 3. The method according to claim 1, characterized in that, The environmental boundary for the high-temperature single extreme operating condition is: the ambient temperature is within the range of (40℃, 120℃), and the altitude is less than 3000m; the power correction value is the high-temperature system loss power correction value κ. 12 The range adjustment parameter is the high temperature range adjustment parameter n. 12 Target output power P O via κ 12 With n 12 Construct a computational model; Under high-temperature single extreme operating conditions, the target required output power is less than the system rated power to meet the protection requirements of the adapter components and reduce power output efficiency loss; the high-temperature system loss power correction value κ 12 The calculation formula is as follows: The high temperature range adjustment parameter n 12 The calculation formula is as follows: Where κ2 is the engine or generator speed correction value corresponding to the air pressure under normal operating conditions, and the target required output power P O The calculation model is as follows: 。 4. The method according to claim 1, characterized in that, The environmental boundaries for the high-altitude single extreme operating condition are: ambient temperature within the range of [0℃, 40℃], and altitude greater than 3000m; under the high-altitude single extreme operating condition, the atmospheric pressure P ac The power correction value varies non-linearly with altitude h, and the power correction value is the engine or generator speed correction value κ corresponding to the high altitude air pressure. 21 The interval adjustment parameter is the high-altitude interval adjustment parameter n. 21 The κ 21 The calculation formula is as follows: Among them, the pressure ratio ， The standard atmospheric pressure at zero altitude, n 21 The calculation formula is as follows: κ1 represents the power correction value corresponding to system losses under different temperature conditions during normal operation, and the target required output power P is... O The calculation model is as follows: 。 5. The method according to any one of claims 1-4, characterized in that, The method is applicable to power systems consisting of an engine and a generator, where the engine and generator are directly connected and have approximately equal speeds.

Images