High-temperature test method for high-voltage performance of unmanned logistics vehicle

Abstract

The invention discloses a high-voltage performance high-temperature test method for an unmanned logistics vehicle, and belongs to the technical field of vehicle test. Two initial states of a cold vehicle and a hot vehicle are designed, and three typical operation scenes of high voltage, slow charging and fast charging on a button are combined, so that a set of complete high-temperature test process is constructed; the method specifically comprises six testing steps of high voltage on a cold vehicle button, high voltage on a hot vehicle button, hot vehicle slow charging, hot vehicle quick charging, cold vehicle slow charging and cold vehicle quick charging testing. By placing the vehicle in a high-temperature environment of more than 40 DEG C for standing or driving and setting the state of charge of the battery in a specific range, the real operation condition of the unmanned logistics vehicle at extreme high temperature is simulated. According to the invention, the power-on reliability, the relay operation time sequence and the charging and discharging function stability of the high-voltage system in the high-temperature environment can be comprehensively and systematically verified, the potential failure mode is effectively exposed, and a key test basis is provided for improving the safety and reliability of the unmanned logistics vehicle in the high-temperature environment.

Description

Technical Field

[0001] This invention relates to the field of vehicle testing technology, and in particular to a high-temperature test method for the high-voltage electrical performance of unmanned logistics vehicles. Background Technology

[0002] As a core component of the intelligent logistics system, the reliability of the high-voltage electrical system of unmanned logistics vehicles directly affects their continuous operation and safety. The high-voltage electrical system mainly includes key components such as the battery pack, motor controller, DC-DC converter, main and negative relays, pre-charge relay, and charging relay. Its performance is significantly affected by temperature. In summer or high-temperature regions, unmanned logistics vehicles often face extreme conditions such as prolonged exposure to direct sunlight (cold engine state) and continuous medium-to-high-speed driving (hot engine state) followed immediately by high-voltage charging or other extreme conditions. Under such high-temperature environments, the high-voltage system components are prone to performance degradation due to thermal stress. For example, relay contacts may experience increased contact resistance or adhesion due to high-temperature oxidation; the pre-charge sequence may become disordered due to changes in capacitor characteristics, leading to power-on failure or arcing risks; the DC-DC converter may experience reduced efficiency or trigger overheat protection due to insufficient heat dissipation; and the charging process may be interrupted or its efficiency reduced due to high system temperatures. Currently, industry testing of new energy vehicles largely focuses on ambient temperature or single high-temperature scenarios, lacking a comprehensive high-temperature testing method that can systematically simulate the full-cycle cycle of "cold vehicle inactivity - hot vehicle operation - multiple charging methods" experienced by unmanned logistics vehicles in actual operation. Existing testing methods often suffer from incomplete scenario coverage, unrealistic operating condition simulation, and insufficiently stringent testing conditions, making it difficult to fully expose the collaborative working capabilities and potential failure risks of high-voltage systems under high-temperature environments. Therefore, there is an urgent need in this field for a comprehensive high-voltage electrical performance testing method that can fully simulate the extreme high-temperature operating conditions of unmanned logistics vehicles to verify the reliability, stability, and safety of their high-voltage systems under complex thermal environments. Summary of the Invention

[0003] The purpose of this invention is to provide a high-temperature test method for the high-voltage electrical performance of unmanned logistics vehicles, so as to solve the problems mentioned in the background art.

[0004] This invention is achieved through the following technical solution: A high-temperature test method for the high-voltage electrical performance of an unmanned logistics vehicle, the method comprising the following steps: Step (1) Cold start button high voltage test: After the vehicle is in sleep mode, place it in an environment with an ambient temperature of 40°C or higher for more than 8 hours, then perform multiple high voltage operation operations and check whether the high voltage system is successfully powered on and the working status of key components. Step (2) High voltage test on the hot start button: Run the vehicle continuously for two hours under conditions including medium and high speed driving to establish a hot start state. Then, perform multiple high voltage operation operations and check whether the high voltage system is successfully powered on and the working status of key components. Step (3) Hot-start slow charging test: Drive the vehicle to a hot-start state where the battery charge is between 20% and 30%, and perform slow charging at an ambient temperature above 40°C, and test the high voltage power-on and charging function during the charging process. Step (4) Hot-start fast charging test: Drive the vehicle to a hot-start state where the battery charge is between 20% and 30%, perform fast charging at an ambient temperature above 40°C, and test the high voltage power-on and charging function during the charging process. Step (5) Cold start slow charging test: The vehicle battery charge state is reduced to between 8% and 12%, and the vehicle is left to stand still for more than 8 hours in an ambient temperature above 40°C after the vehicle is in hibernation. Then, slow charging is performed until the battery is fully charged, and dynamic operation test including at least 5 full throttle acceleration operations is performed. Step (6) Cold-start fast charging test: The vehicle battery charge level is reduced to between 8% and 12%. After the vehicle is put into hibernation, it is left to stand for more than 8 hours in an ambient temperature above 40°C. Then, fast charging is performed until it is fully charged, and dynamic operation test including at least 5 full-throttle acceleration operations is carried out.

[0005] Furthermore, the step (1) of checking the status of the high-voltage system specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay and the precharge relay; Check if the DC-DC converter is working properly.

[0006] Furthermore, step (2) of checking the high-voltage system status specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay and the precharge relay; Check if the DC-DC converter is working properly.

[0007] Furthermore, the detection of the charging process in step (3) specifically includes: Repeatedly check whether the system has successfully applied high voltage; Check the closing timing of the main negative relay, pre-charge relay, and slow charge relay; Confirm that the slow charging function is working properly.

[0008] Furthermore, the detection of the charging process in step (4) specifically includes: Repeatedly check whether the system has successfully applied high voltage; Check the closing timing of the main negative relay, precharge relay, and fast charge relay; Confirm that the fast charging function is working properly.

[0009] Furthermore, step (5), specifically including the following aspects in the slow charging test before and after the slow charging test and in the dynamic operation test: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay, pre-charge relay, and slow charge relay; Confirm that the slow charging function is working properly.

[0010] Furthermore, step (6), in the process of performing fast charging before and after charging and dynamic operation testing, specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay, precharge relay, and fast charge relay; Confirm that the fast charging function is working properly.

[0011] Furthermore, the medium-to-high speed driving conditions under the warm-up state are established, including general traffic condition simulation, constant speed driving, acceleration and deceleration operations.

[0012] Furthermore, the stationary condition involves placing the vehicle close to the leeward wall to simulate a high-temperature, low-wind-speed environment.

[0013] Furthermore, in steps (3) and (4), the vehicle achieves the battery state of charge by performing at least 10 full-throttle acceleration overtaking operations.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: 1. This invention combines cold and hot operating states, as well as three typical operating scenarios—high voltage, slow charging, and fast charging—to form a complete test matrix consisting of six core test steps. This design simulates the entire lifecycle of an unmanned logistics vehicle, from static wake-up and daily driving to energy replenishment. It enables closed-loop and comprehensive reliability verification of the high-voltage electrical system, overcoming the shortcomings of existing single and one-sided testing methods.

[0015] 2. By setting specific conditions such as "ambient temperature above 40℃", "stationary for more than 8 hours", and "close to the leeward wall to simulate low wind speed", the extreme thermal environment of high temperature and low heat dissipation was accurately reproduced. At the same time, by precisely controlling the battery state of charge (SOC of 20%-30% and 8%-12%) and introducing high-intensity driving operations such as "at least 10 full-throttle acceleration overtaking" and "at least 5 full-throttle acceleration dynamic operations", the rigor and realism of the test conditions were greatly enhanced. This can effectively stimulate and expose the potential failure modes of the high-voltage system under extreme conditions, such as relay timing disorder and DC-DC converter overheating. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only preferred embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This invention provides a schematic diagram of the overall process structure of a high-temperature test method for the high-voltage electrical performance of unmanned logistics vehicles. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0019] To fully understand this invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this invention. Optional embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0020] See Figure 1 A high-temperature test method for the high-voltage electrical performance of an unmanned logistics vehicle, the method comprising the following steps: Step (1) Cold start button high voltage test: After the vehicle is in sleep mode, place it in an environment with an ambient temperature of 40°C or higher for more than 8 hours, then perform multiple high voltage operation operations and check whether the high voltage system is successfully powered on and the working status of key components. Step (2) High voltage test on the hot start button: Run the vehicle continuously for two hours under conditions including medium and high speed driving to establish a hot start state. Then, perform multiple high voltage operation operations and check whether the high voltage system is successfully powered on and the working status of key components. Step (3) Hot-start slow charging test: Drive the vehicle to a hot-start state where the battery charge is between 20% and 30%, and perform slow charging at an ambient temperature above 40°C, and test the high voltage power-on and charging function during the charging process. Step (4) Hot-start fast charging test: Drive the vehicle to a hot-start state where the battery charge is between 20% and 30%, perform fast charging at an ambient temperature above 40°C, and test the high voltage power-on and charging function during the charging process. Step (5) Cold start slow charging test: The vehicle battery charge state is reduced to between 8% and 12%, and the vehicle is left to stand still for more than 8 hours in an ambient temperature above 40°C after the vehicle is in hibernation. Then, slow charging is performed until the battery is fully charged, and dynamic operation test including at least 5 full throttle acceleration operations is performed. Step (6) Cold-start fast charging test: The vehicle battery charge level is reduced to between 8% and 12%. After the vehicle is put into hibernation, it is left to stand for more than 8 hours in an ambient temperature above 40°C. Then, fast charging is performed until it is fully charged, and dynamic operation test including at least 5 full-throttle acceleration operations is carried out.

[0021] For example, the high-voltage test on the cold start button simulates a cold start scenario after a vehicle has been stationary for a long time in a high-temperature environment. The vehicle needs to be stationary for more than 8 hours in an environment above 40°C to ensure that the entire vehicle is in a state of deep heat immersion. Then, the high-voltage operation is performed multiple times to test whether the high-voltage system can be successfully energized and to verify whether the closing sequence of the main negative relay and the pre-charge relay conforms to the design logic. At the same time, it is confirmed that the DC-DC converter can work properly to supply power to the low-voltage system, so as to verify the initial reliability of the high-voltage system under extreme high-temperature static environment. The high-voltage test on the hot start button focuses on the performance of the high-voltage system under dynamic hot start conditions. The vehicle needs to run continuously for two hours under conditions including medium and high speed driving, through general traffic conditions and constant speed. The system establishes a warm-up state through driving, acceleration, and deceleration operations, followed by multiple high-voltage operations. In this scenario, the high-voltage system must still respond quickly to power-on commands after dynamic operation at high temperatures, and the relay timing and DC-DC converter operation must remain stable to verify the continuous reliability of the high-voltage system under warm-up conditions. In the charging scenario test, two sets of comparative scenarios were designed: a warm-up slow / fast charging test and a cold-up slow / fast charging test. The warm-up charging test requires the vehicle to reach a battery charge level of 20%-30% and then perform slow or fast charging at high temperatures. The focus is on testing the stability of high-voltage power-on and the normality of the charging function during charging, while also checking the correct coordination timing of the slow / fast charging relays with the main and negative, and pre-charge relays. The cold-up charging test requires the vehicle battery to be depleted to 8%-12% and then left idle for more than 8 hours to simulate a cold start charging scenario. After charging, at least five full-throttle acceleration tests are required to verify the stability of the high-voltage system under extreme dynamic conditions after charging.

[0022] This invention can cover high-voltage systems in all scenarios under high-temperature environments: from cold start to warm-up operation, from slow charging to fast charging, from static charging to dynamic acceleration, forming a closed-loop verification chain. In particular, the detailed design of placing the vehicle near the leeward wall under static conditions simulates a real environment of high temperature and low wind speed, improving the realism of the test scenario. The requirement of 10 full-throttle acceleration overtaking operations ensures that the battery reaches the target state of charge in a warm-up state, making the test conditions closer to the high-intensity use scenarios of actual logistics vehicles. This ensures that the test method can fully expose the potential failure modes of the high-voltage system in high-temperature environments, providing reliable data support for the design optimization of the high-voltage electrical system of unmanned logistics vehicles, and ultimately improving the operational safety and reliability of vehicles in extreme high-temperature environments.

[0023] The step (1) of checking the status of the high-voltage system specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay and the precharge relay; Check if the DC-DC converter is working properly.

[0024] For example, a three-dimensional evaluation system for the cold start reliability of a high-voltage system under high-temperature conditions is constructed through verification of three key parameters. First, the successful connection of the system to high voltage serves as a fundamental indicator, directly verifying the vehicle's initial electrification capability after being left to stand still at high temperatures. This confirms whether the high-voltage system can complete the basic transition from dormancy to activation. By performing multiple high-voltage connection operations, accidental faults are eliminated, ensuring that the system's starting stability under high-temperature conditions meets commercial-grade requirements. Second, the closing sequence of the main negative relay and the pre-charge relay is checked. In a high-voltage system, the closing sequence of the relays directly affects the risk of high-voltage arcing and the protection logic of the electrical system. If the pre-charge relay closes prematurely, it may cause the relay to stick due to excessive instantaneous charging current of the capacitor. If the main negative relay closes late, it may trigger a system error due to the failure to establish high-voltage bus voltage. By accurately verifying whether the timing conforms to the design logic, it can be ensured that the high-voltage system avoids electrical shocks and guarantees power supply continuity during cold starts. Finally, the operation status check of the DC-DC converter focuses on the coordination between the high-voltage system and the low-voltage system. Regarding reliability, the DC-DC converter, as a key component for supplying power from the high-voltage battery to the 12V low-voltage system, directly affects the normal operation of low-voltage devices such as vehicle ECUs, sensors, and actuators. In high-temperature environments, the converter may experience efficiency decline or overheating protection due to temperature rise, leading to unstable power supply to the low-voltage system or even vehicle breakdown. By confirming its normal operating status, it can be ensured that the high-voltage system is not only stable itself but also effectively supports the needs of the vehicle's low-voltage system, forming a complete high-voltage-low-voltage energy flow closed loop. These three checks are not isolated but are constructed through the dual constraints of timing logic and functional verification, building a full-link reliability verification from high-voltage power-on to low-voltage power supply in high-temperature cold start scenarios. This design allows the test method to not only discover direct faults in the high-voltage system but also trace back to deeper technical issues such as relay control strategies and converter thermal management, providing precise fault location and improvement directions for the design optimization of the high-voltage electrical system of unmanned logistics vehicles, ultimately achieving a three-in-one safety guarantee of "cold start-stable operation-strong power supply" for vehicles in extreme high-temperature environments.

[0025] The step (2) of checking the high-voltage system status specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay and the precharge relay; Check if the DC-DC converter is working properly.

[0026] For example, a specific verification logic for the reliability of the high-voltage system after high-temperature dynamic operation was constructed for the high-voltage test scenario on the hot-operation button. This logic uses a three-dimensional verification framework of "start-timing-coordination" to accurately capture the potential failure modes of the high-voltage system under hot-operation conditions. First, the successful connection of the system to high voltage has unique verification value in the hot-operation scenario. After the vehicle has been driven at medium to high speed for two hours to establish a hot-operation state, the high-voltage system needs to complete the power-on process again under high-temperature dynamic operation. This check not only verifies the immediate start-up capability of the high-voltage system under hot-operation conditions, but also eliminates accidental failures caused by "thermal fatigue" through repeated operations, ensuring that the system can still maintain commercial-grade start-up stability after high-temperature dynamic operation. Compared to the cold-operation state, the high-voltage system under hot-operation conditions faces a higher temperature gradient and thermal stress. This check can better reflect the reliability boundary of the system after continuous operation in real logistics scenarios. Second, the closing timing check of the main negative relay and the pre-charge relay has a deeper safety significance in the hot-operation scenario. After high-temperature dynamic operation, the temperature rise of the electrical system may change the physical characteristics of the relay contacts. If the timing control is not proper, it may easily lead to arcing risks or power outages. By precisely verifying that the timing conforms to the design logic, it can be ensured that, under hot-operation conditions, the high-voltage system can avoid relay sticking or false triggering due to temperature rise, and also ensure the stable establishment of the high-voltage bus voltage. Finally, the operation status check of the DC-DC converter in hot-operation scenarios focuses on the coordinated reliability of thermal management and energy conversion. After high-temperature operation, the converter may experience efficiency degradation or overheat protection triggering due to temperature accumulation, directly affecting the power supply stability of the low-voltage system. By confirming that its operation status is normal, it can be ensured that the high-voltage system is not only stable itself under hot-operation conditions, but can also continuously provide reliable power to the vehicle's low-voltage equipment, forming a "high-voltage-low-voltage" energy transfer. The closed-loop verification of the flow under high-temperature dynamic environment forms a progressive verification chain of "start-up capability - timing safety - coordinated power supply" in the hot vehicle scenario. It not only covers the basic functions of the high-voltage system after high-temperature dynamic operation, but also delves into the deep technical dimensions such as relay control strategy and converter thermal management. This design enables the test method to not only discover high-voltage system faults in the hot vehicle state, but also trace potential defects at the design level. It provides accurate fault location and improvement direction for the optimization of the high-voltage electrical system of unmanned logistics vehicles in high-temperature dynamic environment, and ultimately achieves the three-in-one safety guarantee of "hot start-up-stable operation-strong coordination" for vehicles in continuous high-temperature operation.

[0027] The detection of the charging process in step (3) specifically includes: Repeatedly check whether the system has successfully applied high voltage; Check the closing timing of the main negative relay, pre-charge relay, and slow charge relay; Confirm that the slow charging function is working properly.

[0028] For example, for the reliability verification of the high-voltage system in the hot-car slow charging scenario, a three-dimensional detection logic of repeated start verification, multi-relay timing coordination, and charging function confirmation is constructed to build a special safety barrier for slow charging in the hot-car state. This allows for precise control of the entire charging process and the elimination of potential risks at each level. Repeatedly checking whether the system has successfully reached the high voltage is the basic reliability verification in the hot-car slow charging scenario. After the vehicle has established a hot-car state through medium- and high-speed driving, the high-voltage system needs to complete multiple power-on operations in a high-temperature environment. This design not only verifies the system's immediate start-up capability in the hot-car state, but also eliminates accidental failures caused by thermal fatigue through repeated operations. In a high-temperature environment, electrical components may experience performance drift due to temperature accumulation. A single successful power-on may mask potential problems, while multiple operations can ensure that the system's start-up stability in the hot-car state meets commercial-grade requirements, providing a reliable power-on foundation for slow charging.

[0029] Checking the closing sequence of the main negative relay, pre-charge relay, and slow-charge relay is a core technical guarantee for charging safety. During slow charging, the coordinated closing of the three sets of relays must follow a strict timing logic: the pre-charge relay must close first to limit the capacitor charging current and avoid the risk of arcing; then the main negative relay closes to establish the high-voltage bus voltage; finally, the slow-charge relay closes to introduce the charging current. If the timing is disordered, it may cause relay sticking, voltage fluctuations, or even system errors. By accurately verifying whether the timing conforms to the design logic, it can be ensured that the charging path is both safe and efficient under high-temperature and hot vehicle conditions. This is the core safety design of the high-voltage system in charging scenarios.

[0030] Confirming the proper functioning of the slow charging function is directly related to actual usage needs. In the case of a hot vehicle at high temperatures, slow charging may face problems such as reduced efficiency and overheat protection triggering. By confirming that the charging function is normal, it can be ensured that the vehicle can still complete the charging task in high-temperature environments, meeting the range requirements of logistics vehicles for long-term operation. This check not only verifies whether the charging current and voltage meet the standards, but also tests the system's continuous working capability at high temperatures through the actual charging process, forming a closed loop of the entire chain from "power-on - charging - function verification".

[0031] These three tests form a progressive verification system of startup reliability, charging safety, and functional effectiveness in the hot-vehicle slow-charging scenario. It covers the basic functions of the high-voltage system under high-temperature hot-vehicle conditions and delves into deeper technical dimensions such as relay control strategies and charging thermal management. This design enables the test method to not only discover surface faults during the slow-charging process but also trace potential defects at the design level. It provides accurate fault location and improvement direction for the optimization of the high-voltage electrical system of unmanned logistics vehicles under high-temperature hot-vehicle conditions, and ultimately achieves the three-in-one guarantee of "stable charging, strong range, and high safety" for vehicles in continuous high-temperature operation.

[0032] The detection of the charging process in step (4) specifically includes: Repeatedly check whether the system has successfully applied high voltage; Check the closing timing of the main negative relay, precharge relay, and fast charge relay; Confirm that the fast charging function is working properly.

[0033] For example, a three-in-one deep verification logic of static-charging-dynamic is constructed for the cold start slow charging scenario. That is, through the dual pressure of extreme static conditions in high temperature environment and high load dynamic test after charging, the full-cycle reliability of high voltage system in cold start charging scenario is accurately evaluated, so as to realize the closed-loop verification of the whole chain of static state-charging process-dynamic operation.

[0034] The successful application of high voltage to the system has unique verification value in the cold vehicle slow charging scenario. After the vehicle battery is depleted to 8%-12% and left to stand still for more than 8 hours, the high voltage system needs to complete the transition from deep dormancy to activation in a high-temperature environment. This check not only verifies the initial start-up capability of the system under extreme stand-up conditions, but also eliminates potential risks such as electrical parameter drift caused by stand-up or accelerated component aging caused by high temperature through the complete process of slow charging to full charge. This ensures that the high voltage system has commercial-grade reliability in the cold start charging scenario. Compared with the hot vehicle state, the high voltage system in the cold vehicle state faces a greater temperature gradient and electrical stress. This check can better reflect the start-up stability boundary of the system after a long period of stand-up in real logistics scenarios.

[0035] The timing check of the closing of the main negative relay, pre-charge relay, and slow-charge relay has profound safety design significance in cold-start slow-charge scenarios. These three sets of relays must follow a strict coordinated timing sequence: the pre-charge relay closes first to limit the capacitor charging current and avoid arcing risks; the main negative relay then closes to establish the high-voltage bus voltage; finally, the slow-charge relay closes to introduce the charging current. In cold-start scenarios after a period of high-temperature stagnation, electrical components may experience performance fluctuations due to temperature changes. If the timing is disordered, it can easily lead to relay sticking, voltage fluctuations, or even system errors. Accurately verifying whether the timing conforms to the design logic ensures that the charging path is both safe and efficient during a cold start, which is the core safety guarantee mechanism for high-voltage systems in cold-start charging scenarios.

[0036] Confirming the proper functioning of the slow charging function extends to the dynamic operation verification after charging. By performing at least five full-throttle acceleration operations, the scenario of a logistics vehicle being put into high-intensity operation immediately after charging can be simulated. This tests the stability of the high-voltage system under the dual pressure of charging and dynamic operation. This design not only verifies whether the charging current and voltage meet the standards, but also tests the system's continuous working capability in high-temperature environments through actual dynamic testing, forming a closed-loop chain from static to charging to dynamic operation. This dynamic test can expose potential defects of the high-voltage system under high load after charging, such as relay thermal stress accumulation and DC-DC converter efficiency degradation, providing accurate fault location for system optimization.

[0037] These three tests form a progressive verification system of stationary start-up, charging safety, and dynamic verification in the cold vehicle slow charging scenario. It not only covers the basic functions of the high-voltage system in the cold start charging scenario, but also delves into deeper technical dimensions such as relay control strategies, charging thermal management, and dynamic load bearing capacity. This design enables the test method to not only discover surface faults in the cold vehicle slow charging process, but also trace potential defects at the design level. It provides precise improvement directions for the optimization of the high-voltage electrical system of unmanned logistics vehicles in the high-temperature cold start charging scenario. Ultimately, it achieves a three-in-one safety guarantee of "cold start charging - steady-state charging - high-load operation" for vehicles in high-temperature extreme environments, ensuring that logistics vehicles can still reliably complete charging tasks and be put into high-intensity operations after long periods of stationary operation.

[0038] Step (5) specifically includes the following aspects during the slow charging process and dynamic operation tests: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay, pre-charge relay, and slow charge relay; Confirm that the slow charging function is working properly.

[0039] For example, for the full-cycle reliability verification of cold-start fast charging scenarios, from pre-charging to charging to post-charging, a three-dimensional testing system of high-voltage verification, timing coordination, and functional confirmation is constructed to build a dedicated safety barrier for fast charging scenarios in high-temperature environments, so as to accurately control and eliminate deep risks in extreme conditions such as cold start fast charging, high current impact, and dynamic load.

[0040] Checking whether the system successfully connects to high voltage runs through the entire fast charging process, providing dual verification value. Before charging, after the vehicle is left to rest at a low battery level of 8% to 12% and then at a high temperature, the high-voltage system needs to complete a cold start process from deep dormancy to activation. This stage verifies whether the system can still stably power on under electrical parameter drift caused by high-temperature resting, eliminating potential risks such as aging due to resting or accelerated failure due to high temperature. After charging and during dynamic operation, the system needs to withstand high-load dynamic tests after the impact of the high current of fast charging (such as 5 full-throttle accelerations) to verify whether the high-voltage system can quickly recover and stably support dynamic operation after fast charging, ensuring the reliability of logistics vehicles to be put into high-intensity operations immediately after charging. This dual verification design before and after charging allows the test method to accurately capture potential failure points in the entire chain of cold start-charging-dynamic operation in fast charging scenarios.

[0041] The timing check of the closing sequence of the main negative relay, pre-charge relay, and fast-charge relay is a core technical guarantee for fast-charging safety. In fast-charging scenarios, the three sets of relays must follow strict coordination logic: the pre-charge relay closes first to limit the instantaneous current of the capacitor and avoid the risk of arcing; the main negative relay then closes to establish the high-voltage bus voltage; finally, the fast-charge relay closes to introduce a large current for charging. If the timing is disordered, current surges may cause relay sticking, voltage fluctuations, or even system failures. By accurately verifying whether the timing conforms to the design logic, it can be ensured that the charging path is both safe and efficient in cold-start fast-charging scenarios after high-temperature quiescence, avoiding electrical risks caused by "timing mismatch". This is the core safety design of high-voltage systems in fast-charging scenarios.

[0042] Confirming the normal operation of fast charging extends to verifying its efficiency and thermal management. In fast charging scenarios, high-current charging can easily lead to system heat accumulation, which may result in decreased charging efficiency, triggering overheat protection, or accelerated component aging. To confirm that the charging function is normal, it is necessary to verify whether the charging current and voltage meet the design standards, whether the system's thermal management is effective during charging, and whether the system can stably support dynamic operation after charging. This check not only verifies the functionality of fast charging but also tests the system's thermal tolerance and continuous working ability under high temperature and high current conditions through the actual charging process, forming a closed-loop verification of the entire chain from power-on to charging to dynamic operation.

[0043] These three tests form a progressive verification system in the cold-start fast charging scenario, encompassing cold start power-on, charging sequence safety, and dynamic function verification. This system covers the basic functions of the high-voltage system in high-temperature cold start fast charging scenarios, and delves into deeper technical dimensions such as relay control strategies, fast charging thermal management, and dynamic load-bearing capacity. This design enables the testing method to not only discover surface faults during the fast charging process but also trace potential defects at the design level. It provides precise fault location and improvement directions for optimizing the high-voltage electrical system of unmanned logistics vehicles in high-temperature cold start fast charging scenarios. Ultimately, it achieves a three-in-one safety guarantee for vehicles in extreme high-temperature environments, including cold start fast charging, steady-state charging, and high-load operation. This ensures that logistics vehicles can reliably complete fast charging tasks and be put into high-intensity operations even after being idle with low battery power.

[0044] Step (6) specifically includes the following aspects during the fast charging process, including pre- and post-charging tests and dynamic operation tests: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay, precharge relay, and fast charge relay; Confirm that the fast charging function is working properly.

[0045] For example, a three-dimensional verification system covering the entire charging cycle, multiple dimensions, and deep risks was constructed for cold-start scenarios. This system enables precise control and in-depth exploration of potential failure modes in extreme operating conditions such as static cold start, high-current impact during fast charging, and dynamic operation after charging. Ultimately, this forms a full-link guarantee from power-on safety to charging efficiency and dynamic reliability.

[0046] The system's successful high-voltage connection is checked throughout the entire cold-start fast charging process, employing a dual verification logic: Before charging, after the vehicle has been left to stand at low battery (8%-12%) and high temperature, the high-voltage system must complete a cold start process from deep dormancy to activation. This stage focuses on verifying whether the system can still stably power on under adverse conditions such as electrical parameter drift and component aging caused by high-temperature standing, eliminating potential risks such as standing failure or accelerated degradation due to high temperature. After charging and during dynamic operation, the system must withstand the impact of the high current during fast charging and immediately perform a high-load dynamic test of 5 full-throttle accelerations. This verifies whether the high-voltage system can quickly recover and stably support high-intensity dynamic operation after fast charging, ensuring the reliability of the logistics vehicle to be put into operation directly after charging. This dual verification design before and after charging allows the test method to accurately capture potential failure points in the entire chain of cold start-charging-dynamic operation in fast charging scenarios, such as deep-seated problems like relay thermal stress accumulation and DC-DC converter efficiency degradation.

[0047] The timing check of the closing sequence of the main negative relay, pre-charge relay, and fast-charge relay is a core technological pillar of fast-charging safety. In cold-start fast-charging scenarios, the three sets of relays must follow strict coordination logic: the pre-charge relay closes first to limit the instantaneous charging current of the capacitor and avoid the risk of arcing; the main negative relay then closes to establish the high-voltage bus voltage; and finally, the fast-charge relay closes to introduce a large current for charging. If the timing is disordered, current surges may cause relay sticking, voltage fluctuations, or even system failures. Especially in the cold-start state after being left to stand at high temperatures, the physical characteristics of electrical components may fluctuate due to temperature changes, resulting in a lower tolerance for timing coordination errors. By accurately verifying whether the timing conforms to the design logic, it can be ensured that the charging path is both safe and efficient in cold-start fast-charging scenarios, avoiding electrical risks caused by timing mismatches. This is the core safety design of high-voltage systems in fast-charging scenarios.

[0048] Confirming the normal operation of fast charging extends to verifying its efficiency, thermal management, and dynamic adaptability. In fast charging scenarios, high-current charging can easily lead to system heat accumulation, which may result in decreased charging efficiency, triggering overheat protection, or accelerated component aging. To confirm the normal operation of the charging function, it is necessary to verify whether the charging current and voltage meet the design standards, whether the system's thermal management is effective during charging (such as heat dissipation efficiency and temperature threshold control), and whether the system can stably support dynamic operation after charging (such as voltage stability during full-throttle acceleration and relay thermal stress recovery capability). This check not only verifies the functionality of fast charging but also tests the system's thermal tolerance and continuous working capability under high-temperature and high-current environments through actual charging and dynamic testing processes. This forms a closed-loop verification of the entire chain from power-on to charging to dynamic operation, ensuring that the logistics vehicle can reliably complete the fast charging task and be put into high-intensity operation even after being idle with low battery.

[0049] These three checks form a progressive verification system in the cold-start power-on safety, charging timing coordination, and dynamic function verification in the cold vehicle fast charging scenario. It not only covers the basic functions of the high-voltage system in the high-temperature cold start fast charging scenario, but also delves into deeper technical dimensions such as relay control strategies, fast charging thermal management, and dynamic load bearing capacity. This design enables the test method to not only discover surface faults in the fast charging process, but also trace potential defects at the design level. It provides accurate fault location and improvement direction for the optimization of the high-voltage electrical system of unmanned logistics vehicles in the high-temperature cold start fast charging scenario. Ultimately, it achieves a three-in-one safety guarantee of "cold start fast charging - steady-state charging - high load operation" for vehicles in high-temperature extreme environments, ensuring that logistics vehicles can still efficiently and safely complete fast charging tasks and be put into high-intensity operations after being idle for a long time.

[0050] Establish medium-to-high speed driving conditions under the warm-up state, including general traffic conditions, constant speed driving, acceleration and deceleration operations.

[0051] For example, a refined verification logic for establishing a hot-running state was constructed through multi-scenario working condition simulation. Through a three-dimensional design of real road condition reproduction, dynamic load superposition, and system response capture, the actual operating characteristics of unmanned logistics vehicles in high-temperature environments were accurately reproduced, thereby providing a more engineering-value test scenario for high-voltage system reliability verification.

[0052] General traffic condition simulation is the basic scenario reproduction for establishing the warm-up state of a vehicle. In actual operation, logistics vehicles often face complex road conditions such as urban roads and industrial roads, including typical scenarios such as starting and stopping at traffic lights, driving on curves, and following other vehicles at low speeds. By simulating these road conditions, the dynamic response capability of the high-voltage system in real traffic flow can be verified. For example, whether frequent starting and stopping leads to heat accumulation caused by frequent relay operation, or the stress effect of lateral acceleration on the high-voltage wiring harness when driving on curves. This simulation makes the warm-up state closer to the actual use scenario, avoiding the disconnect between "ideal laboratory conditions" and "real operating conditions", and ensuring that the test results can directly guide vehicle design optimization.

[0053] The constant-speed driving scenario focuses on verifying the steady-state thermal management capabilities of the high-voltage system. In a high-temperature environment, when the vehicle travels at a constant speed of medium to high, the high-voltage system must continuously withstand the heat generated by core components such as the motor, electronic control system, and battery. This scenario allows for the testing of the high-voltage system's temperature distribution, heat dissipation efficiency, and the thermal stability of key components (such as relays and DC-DC converters) during steady-state operation. For example, during constant-speed driving, the main and negative relays may experience temperature rise due to continuous current flow. Improper heat dissipation design could lead to relay contact oxidation or performance degradation. Verification through this scenario ensures that the high-voltage system maintains stable electrical parameters during high-temperature steady-state operation, preventing system failures caused by heat accumulation.

[0054] Acceleration and deceleration operations focus on verifying the dynamic load-bearing capacity of the high-voltage system. Logistics vehicles frequently accelerate to overtake or decelerate and brake in actual operation. These operations cause drastic fluctuations in the high-voltage system current, posing severe challenges to the timing control of relays, the instantaneous charging and discharging capacity of capacitors, and the dynamic response of the DC-DC converter. For example, during full-throttle acceleration, the surge in motor current demand can lead to voltage fluctuations on the high-voltage bus. Improper timing control of the pre-charge relay and the main negative relay can easily cause voltage surges or relay sticking. During deceleration and braking, the energy recovery system intervenes, potentially triggering reverse current surges, testing the reverse withstand voltage capability of the high-voltage system. Verification through this scenario ensures that the high-voltage system can maintain stable operation under dynamic load changes, avoiding electrical faults caused by current surges.

[0055] The collaborative simulation of these three operating conditions forms a progressive verification system of steady-state thermal management, dynamic load bearing, and real-world scenario reproduction during the establishment of the hot-run state. This design enables the test method to not only discover surface faults in the high-voltage system during high-temperature operation, but also to trace back to deeper technical dimensions such as thermal management strategies, relay control logic, and dynamic current tolerance capabilities. This provides accurate fault location and improvement directions for the design optimization of the high-voltage electrical system of unmanned logistics vehicles in high-temperature environments, ultimately achieving a three-in-one safety guarantee of "steady-state operation, dynamic response, and real-world scenario adaptation" for vehicles in continuous high-temperature operation.

[0056] The static condition involves placing the vehicle close to the leeward wall to simulate a high-temperature, low-wind-speed environment.

[0057] For example, by designing static conditions close to the leeward wall, a precise simulation logic for a high-temperature, low-wind-speed environment is constructed. Through a three-dimensional design of real-scene reproduction, heat accumulation enhancement, and system response capture, a more engineering-value extreme thermal environment test scenario is provided for the reliability verification of high-voltage systems, so as to accurately control and deeply explore the combined working conditions of high-temperature heat immersion and low-wind-speed heat dissipation suppression.

[0058] The physical layout design, positioned close to the leeward wall, directly replicates the leeward parking scenarios commonly encountered by unmanned logistics vehicles in actual operation. For example, when logistics vehicles are parked in industrial areas, next to warehouses, or on the leeward side of buildings, they are often in an environment with high temperatures and extremely low wind speeds—the high temperatures cause the ambient temperature to remain above 40°C, while the low wind speeds inhibit natural convection cooling, causing the vehicle's surface and internal systems to experience a stronger heat accumulation effect. This design shifts the test environment from "ideal high temperatures in the laboratory" to "extreme thermal environments in real-world operation," ensuring that the test results directly reflect the vehicle's thermal management performance in actual use.

[0059] In high-temperature, low-wind-speed environments, the heat immersion effect of vehicles is significantly amplified. Key components in the high-voltage system, such as the battery pack, motor controller, and relays, experience rapid temperature increases due to the superposition of their own heat generation and ambient heat. Low wind speeds reduce natural heat dissipation, leading to heat accumulation within the system and creating a vicious cycle of "high temperature - low heat dissipation." For example, at high temperatures, the main and negative relays may experience increased contact resistance due to the expansion of contact materials, causing localized overheating. DC-DC converters may experience decreased efficiency or trigger overheat protection due to poor heat dissipation. This design precisely captures these potential failure modes caused by "enhanced heat accumulation," providing a direct basis for system optimization.

[0060] In steps (3) and (4), the vehicle achieves the battery state of charge by performing at least 10 full-throttle acceleration overtaking operations.

[0061] For example, by quantitatively designing 10 full-throttle acceleration overtaking operations, an engineering logic for precise control of the battery's state of charge (SOC) under hot-run conditions was constructed. Through the cumulative effect of high-intensity dynamic operations, the battery discharge characteristics of unmanned logistics vehicles in high-frequency acceleration scenarios during actual operation were accurately simulated. This provides a more realistic initial state for high-temperature charging tests, enabling precise control of the relationship between "dynamic load, discharge efficiency, and SOC" and in-depth failure mode discovery. The quantitative requirement of at least 10 full-throttle acceleration overtaking operations directly corresponds to the "high-frequency overtaking" scenario commonly encountered by logistics vehicles in real operations. For example, in industrial zone logistics transportation, vehicles need to frequently overtake slower vehicles or weave through cargo flows. Each acceleration overtaking will trigger a large current output from the motor, causing the battery to discharge rapidly. Through the accumulation of 10 operations, the consumption effect of this high-intensity dynamic load on the battery's SOC can be accurately simulated, keeping the vehicle's battery SOC stable in the 20%-30% hot-run charging test range. This avoids test condition deviations caused by a single operation failing to reach the target state or excessive discharge.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-temperature test method for the high-voltage electrical performance of an unmanned logistics vehicle, characterized in that, The method includes the following steps: Step (1) Cold start button high voltage test: After the vehicle is in sleep mode, place it in an environment with an ambient temperature of 40°C or higher for more than 8 hours, then perform multiple high voltage operation operations and check whether the high voltage system is successfully powered on and the working status of key components. Step (2) High voltage test on the hot start button: Run the vehicle continuously for two hours under conditions including medium and high speed driving to establish a hot start state. Then, perform multiple high voltage operation operations and check whether the high voltage system is successfully powered on and the working status of key components. Step (3) Hot-start slow charging test: Drive the vehicle to a hot-start state where the battery charge is between 20% and 30%, and perform slow charging at an ambient temperature above 40°C, and test the high voltage power-on and charging function during the charging process. Step (4) Hot-start fast charging test: Drive the vehicle to a hot-start state where the battery charge is between 20% and 30%, perform fast charging at an ambient temperature above 40°C, and test the high voltage power-on and charging function during the charging process. Step (5) Cold start slow charging test: The vehicle battery charge state is reduced to between 8% and 12%, and the vehicle is left to stand still for more than 8 hours in an ambient temperature above 40°C after the vehicle is in hibernation. Then, slow charging is performed until the battery is fully charged, and dynamic operation test including at least 5 full throttle acceleration operations is performed. Step (6) Cold-start fast charging test: The vehicle battery charge level is reduced to between 8% and 12%. After the vehicle is put into hibernation, it is left to stand for more than 8 hours in an ambient temperature above 40°C. Then, fast charging is performed until it is fully charged, and dynamic operation test including at least 5 full-throttle acceleration operations is carried out.

2. The method as described in claim 1, characterized in that, The step (1) of checking the status of the high-voltage system specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay and the precharge relay; Check if the DC-DC converter is working properly.

3. The method as described in claim 1, characterized in that, The step (2) of checking the high-voltage system status specifically includes: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay and the precharge relay; Check if the DC-DC converter is working properly.

4. The method as described in claim 1, characterized in that, The detection of the charging process in step (3) specifically includes: Repeatedly check whether the system has successfully applied high voltage; Check the closing timing of the main negative relay, pre-charge relay, and slow charge relay; Confirm that the slow charging function is working properly.

5. The method as described in claim 1, characterized in that, The detection of the charging process in step (4) specifically includes: Repeatedly check whether the system has successfully applied high voltage; Check the closing timing of the main negative relay, precharge relay, and fast charge relay; Confirm that the fast charging function is working properly.

6. The method as described in claim 1, characterized in that, Step (5) specifically includes the following aspects during the slow charging process and dynamic operation tests: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay, pre-charge relay, and slow charge relay; Confirm that the slow charging function is working properly.

7. The method as described in claim 1, characterized in that, Step (6) specifically includes the following aspects during the fast charging process, including pre- and post-charging tests and dynamic operation tests: Check if the system has successfully applied high voltage; Check the closing timing of the main negative relay, precharge relay, and fast charge relay; Confirm that the fast charging function is working properly.

8. The method as described in claim 1, characterized in that, Establish medium-to-high speed driving conditions under the warm-up state, including general traffic conditions, constant speed driving, acceleration and deceleration operations.

9. The method as described in claim 1, characterized in that, The static condition involves placing the vehicle close to the leeward wall to simulate a high-temperature, low-wind-speed environment.

10. The method as described in claim 1, characterized in that, In steps (3) and (4), the vehicle achieves the battery state of charge by performing at least 10 full-throttle acceleration overtaking operations.

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