Passenger transport and freight transport GPS system and road section speed limit threshold value dynamic identification and adjustment method

Abstract

The invention discloses a passenger transport and freight GPS system and a road section speed limit threshold dynamic identification and adjustment method, and relates to the technical field of passenger transport and freight, and the system comprises a positioning module, a navigation module, a code module and a communication module. The positioning module is used for acquiring and providing geographic position information of a vehicle in real time; the navigation module is used for planning an optimal path according to the current position of the vehicle and providing deviation correction guidance when the vehicle deviates from the path; the code module is used for dynamically acquiring road section speed limit information and analyzing and adjusting a speed limit threshold value of a vehicle in real time; and the communication module exchanges data with an external navigation system in real time. According to the passenger transport and freight transport GPS system and the road section speed limit threshold value dynamic identification and adjustment method provided by the invention, rapid acquisition and accurate analysis of speed limit information are realized, the speed threshold value is dynamically adjusted, and acceleration and deceleration instructions are generated. A speed adjusting strategy is optimized, and driving safety and efficiency are ensured. And the virtual model verifies the instruction security, so that the risk caused by improper speed limit is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of passenger and freight transportation, and in particular to a passenger and freight transportation GPS system and a method for dynamically identifying and adjusting a road section speed limit threshold. Background Art

[0002] In the passenger and freight industries, vehicle safety and efficiency are key factors. Although traditional navigation systems can provide basic route planning and speed limit reminders, they often fail to meet the needs when faced with long-distance driving, complex road conditions, and changing speed limit requirements. Drivers are prone to fatigue during long-distance driving, which leads to problems such as ignoring speed limit information or deviating from the route, which in turn increases the risk of accidents.

[0003] Traditional GPS systems have problems such as the contradiction between fixed speed limits and dynamic changes, lagging path planning and deviation correction, and insufficient response to driver fatigue and external environment. Fixed speed limit information cannot dynamically adjust the vehicle's speed limit threshold according to real-time road conditions, causing the vehicle to exceed or underspeed in certain situations, endangering driving safety. Existing navigation systems often lag in path planning and deviation correction, especially in complex road conditions or when the vehicle is driving at high speed. The system cannot correct the vehicle's driving direction in time, increasing the driver's operating burden and reducing driving efficiency and safety.

[0004] Long-distance driving places extremely high demands on the driver's mental and physical strength. Traditional GPS systems cannot effectively monitor the driver's fatigue state, nor can they fully perceive changes in the external environment, resulting in the driver's inability to respond in a timely manner, increasing the possibility of accidents. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is that the existing navigation systems for long-distance passenger and freight vehicles are unable to dynamically adjust the speed limit according to real-time road conditions, and have problems such as delayed path planning and deviation correction, and insufficient driver fatigue monitoring.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: A passenger and freight GPS system, comprising:

[0008] Positioning module, navigation module, code module and communication module;

[0009] The positioning module is used to obtain and provide the geographical location information of the vehicle in real time;

[0010] The navigation module is used to plan the optimal path according to the current position of the vehicle and provide correction guidance when the vehicle deviates from the path;

[0011] The code module is used to dynamically obtain the speed limit information of the road section, analyze and adjust the speed limit threshold of the vehicle in real time, and the speed limit information includes the maximum speed limit and the minimum speed limit;

[0012] The communication module exchanges data with the external navigation system in real time.

[0013] As a preferred solution of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system of the present invention, wherein: the code module adopts a dual-thread architecture;

[0014] The dual-thread architecture includes a first thread and a second thread;

[0015] The first thread is used to obtain real-time road speed limit data from the communication module;

[0016] The second thread is used to parse the road section speed limit data and perform speed limit adjustment according to the path information provided by the navigation module and the current position provided by the positioning module.

[0017] Another object of the present invention is to provide a method for dynamically identifying and adjusting the speed limit threshold of a road section based on a passenger and freight GPS system, which can obtain and analyze speed limit information in real time and dynamically adjust the speed threshold through the collaborative operation of a dual-thread architecture and a dual-lock mechanism, thereby solving the problems in the existing fixed speed limit system that cannot be flexibly adjusted according to real-time road conditions and vehicle status, the speed limit is inaccurate and cannot respond dynamically.

[0018] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for dynamically identifying and adjusting the speed limit threshold of a road section based on a passenger and freight GPS system, comprising:

[0019] The positioning module obtains the real-time geographic location information of the vehicle and synchronously transmits the geographic location information to the navigation module and the code module;

[0020] The navigation module calculates the optimal driving path of the vehicle based on the current position data provided by the positioning module and passes the path information to the code module;

[0021] During the driving process, the navigation module continuously monitors the position of the vehicle. When the vehicle deviates from the planned path, the navigation module provides deviation correction guidance to ensure that the vehicle drives along the planned path.

[0022] The communication module exchanges data with the external navigation system in real time, obtains the speed limit information of the current road section and transmits it to the first thread of the code module;

[0023] Initialize the code module, start the dual-lock mechanism to coordinate dual-thread operation, the first thread receives the speed limit information of the current road section from the communication module, activates the write lock before writing the speed limit information into the cache area, and when the speed limit information is completely written, the write lock is released, allowing the second thread to read the speed limit information;

[0024] Start the second thread and activate the read lock. After reading the speed limit information, the second thread combines the path information provided by the navigation module and the current position provided by the positioning module to parse and determine the speed threshold.

[0025] When the speed limit information is parsed, the read lock is released, and the first thread continues to obtain new speed limit information and write it into the cache area;

[0026] The second thread determines an acceleration or deceleration instruction according to the speed threshold, and applies the acceleration or deceleration instruction to a speed control system of the vehicle.

[0027] As a preferred solution of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system described in the present invention, the initialization code module includes executing an initialization operation, allocating memory resources, and allocating independent cache areas to the first thread and the second thread respectively, the cache area of ​​the first thread is used to store speed limit information; the cache area of ​​the second thread is used to store the parsed speed limit information, the real-time speed of the vehicle, the path information and the location information.

[0028] As a preferred solution of the method for dynamically identifying and adjusting the speed limit threshold of a road section of a passenger and freight GPS system of the present invention, wherein: the parsing and determining the speed threshold includes calculating the driving difficulty coefficient of the current path, adjusting the speed limit information in combination with the driving difficulty coefficient, and generating a preliminary speed threshold;

[0029] The second thread analyzes the real-time speed, acceleration and current position of the vehicle, dynamically adjusts the preliminary speed threshold, and finally determines the speed threshold.

[0030] As a preferred solution of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system of the present invention, the speed threshold is expressed as:

[0031]

[0032] Where D represents the driving difficulty coefficient of the current path, R represents the curvature radius of the road, P represents the slope of the current road, and P r represents the reference road slope, m represents the total mass of the vehicle, g represents the gravitational acceleration constant, h g Indicates the height of the vehicle's center of gravity, I z represents the moment of inertia of the vehicle, μ represents the comprehensive traffic complexity coefficient of the path, T represents the influencing factor of the real-time traffic conditions, and Tr represents the benchmark traffic condition, V max is the maximum speed limit of the current road section, V min is the minimum speed limit, α is the adjustment factor that controls the impact of the driving difficulty coefficient on the speed threshold, and v cur is the current speed, γ1 and γ2 are factors used to adjust the effects of acceleration and speed.

[0033] As a preferred solution of the method for dynamically identifying and adjusting the speed limit threshold of a road section of a passenger and freight GPS system described in the present invention, the method includes determining the acceleration or deceleration instruction based on the speed threshold, and during the vehicle driving process, after parsing the speed threshold through a second thread, comparing the speed threshold with the current speed of the vehicle to determine whether acceleration or deceleration is required, and generating an acceleration or deceleration instruction based on the comparison result.

[0034] As a preferred solution of the method for dynamically identifying and adjusting the speed limit threshold of a road section of a passenger and freight GPS system of the present invention, the generating of the acceleration or deceleration instruction includes generating an acceleration instruction if the current speed is lower than the speed threshold; generating a deceleration instruction if the current speed is higher than the speed threshold;

[0035] Adjusting the generated command taking into account the rate of change of the vehicle's speed and the response time of the accelerator and brake;

[0036] Perform simulation runs on virtual models to verify the effects of acceleration or deceleration instructions;

[0037] If the simulation results show that the instruction may lead to an unsafe situation, the instruction is optimized and adjusted;

[0038] The optimized instructions are applied to the vehicle's speed control system to make the vehicle move.

[0039] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system as described above are implemented.

[0040] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system as described above.

[0041] Beneficial effects of the invention: The passenger and freight GPS system and the method for dynamically identifying and adjusting the speed limit threshold of a road section provided by the invention improve the concurrent processing capability and real-time response performance of the system through the design of a multi-threaded architecture and a dual-lock mechanism, ensure the rapid acquisition and accurate analysis of speed limit information, and avoid data conflicts and processing lags in traditional systems. The system can dynamically adjust the speed threshold of the vehicle under different road sections, and generate the optimal acceleration or deceleration instructions by combining the path information and vehicle positioning.

[0042] The system provides speed adjustment strategies for passenger and freight transport needs by taking into account the road curvature, slope, traffic signal complexity and vehicle dynamic characteristics through speed limit management, improving driving safety and transportation efficiency while reducing the driver's operating burden. The simulation operation of the virtual model ensures the safety and effectiveness of the generated acceleration or deceleration instructions, effectively reducing the risk of accidents caused by improper speed limits. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0044] Figure 1 This is an overall structural diagram of a passenger and freight GPS system provided by one embodiment of the present invention.

[0045] Figure 2 This is an overall flow chart of a method for dynamically identifying and adjusting a road speed limit threshold based on a passenger and freight GPS system provided in accordance with a second embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0047] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0048] Example 1, reference Figure 1, as an embodiment of the present invention, provides a passenger and freight GPS system, including:

[0049] Positioning module, navigation module, code module and communication module;

[0050] The positioning module is used to obtain and provide the vehicle's geographic location information in real time;

[0051] The navigation module is used to plan the optimal path based on the current position of the vehicle and provide correction guidance when the vehicle deviates from the path;

[0052] The code module is used to dynamically obtain the speed limit information of the road section, parse and adjust the speed limit threshold of the vehicle in real time. The speed limit information includes the maximum speed limit and the minimum speed limit;

[0053] The communication module exchanges data with the external navigation system in real time.

[0054] The code module adopts a dual-threaded architecture;

[0055] The dual-thread architecture includes a first thread and a second thread;

[0056] The first thread is used to obtain real-time road speed limit data from the communication module;

[0057] The second thread is used to parse the road section speed limit data and perform speed limit adjustment according to the path information provided by the navigation module and the current position provided by the positioning module.

[0058] Example 2, reference Figure 2 , which is an embodiment of the present invention, provides a passenger and freight GPS system and a method for dynamically identifying and adjusting a road speed limit threshold, including:

[0059] The positioning module obtains the real-time geographic location information of the vehicle and synchronously transmits the geographic location information to the navigation module and the code module;

[0060] The navigation module calculates the optimal driving path of the vehicle based on the current position data provided by the positioning module and passes the path information to the code module;

[0061] During the driving process, the navigation module continuously monitors the position of the vehicle. When the vehicle deviates from the planned path, the navigation module provides deviation correction guidance to ensure that the vehicle drives along the planned path.

[0062] The communication module exchanges data with the external navigation system in real time, obtains the speed limit information of the current road section and transmits it to the first thread of the code module;

[0063] Initialize the code module, start the dual-lock mechanism to coordinate dual-thread operations, the first thread receives the speed limit information of the current road section from the communication module, and activates the write lock to protect the cache area before writing the speed limit information to the cache area to ensure that the data is not read by the second thread during the writing process. When the speed limit information is completely written, the write lock is released to allow the second thread to read the speed limit information;

[0064] Start the second thread, activate the read lock, protect the cache area, and prevent the first thread from modifying or overwriting the data during the process of reading the speed limit information. After reading the speed limit information, the second thread combines the path information provided by the navigation module and the current position provided by the positioning module to parse and determine the speed threshold;

[0065] When the speed limit information is parsed, the read lock is released, and the first thread continues to obtain new speed limit information and write it into the cache area;

[0066] The second thread determines an acceleration or deceleration instruction according to the speed threshold, and applies the acceleration or deceleration instruction to a speed control system of the vehicle.

[0067] The initialization code module includes executing initialization operations, allocating memory resources, and allocating independent cache areas for the first thread and the second thread respectively. The cache area of ​​the first thread is used to store speed limit information; the cache area of ​​the second thread is used to store the parsed speed limit information, the real-time speed of the vehicle, the path information and the location information.

[0068] Parsing and determining the speed threshold includes calculating the driving difficulty coefficient of the current path, adjusting the speed limit information based on the driving difficulty coefficient, and generating a preliminary speed threshold;

[0069] The second thread analyzes the real-time speed, acceleration and current position of the vehicle, dynamically adjusts the preliminary speed threshold, and finally determines the speed threshold.

[0070] The speed threshold is determined as,

[0071]

[0072]

[0073] Where D represents the driving difficulty coefficient of the current path, R represents the curvature radius of the road, P represents the slope of the current road, and P r represents the reference road slope, m represents the total mass of the vehicle, g represents the gravitational acceleration constant, h g Indicates the height of the vehicle's center of gravity, I z represents the moment of inertia of the vehicle, μ represents the comprehensive traffic complexity coefficient of the path, T represents the influencing factor of the real-time traffic conditions, and T r represents the benchmark traffic condition, V max is the maximum speed limit of the current road section, Vmin is the minimum speed limit, α is the adjustment factor that controls the impact of the driving difficulty coefficient on the speed threshold, and v cur is the current speed, γ1 and γ2 are factors used to adjust the effects of acceleration and speed.

[0074] μ=ω1·N i +ω2·L s +ω3·T s

[0075]

[0076] Among them, μ represents the comprehensive traffic complexity coefficient of the path, N i Indicates the number of intersections in the current path segment, L s Indicates the length of the current path segment, T s represents the number of traffic lights, ω1, ω2, ω3 represent the weighting coefficients of each parameter, ρ c is the current traffic flow density, ρ m is the maximum design traffic flow density of the road, Δh is the height difference of the road, and L is the horizontal distance of the road.

[0077] Determining acceleration or deceleration instructions according to the speed threshold includes, during vehicle driving, parsing the speed threshold through the second thread, comparing the speed threshold with the current speed of the vehicle to determine whether acceleration or deceleration is required, and generating acceleration or deceleration instructions based on the comparison result.

[0078] Generating an acceleration or deceleration instruction includes generating an acceleration instruction if the current speed is lower than a speed threshold; generating a deceleration instruction if the current speed is higher than the speed threshold;

[0079] Adjusting the generated command taking into account the rate of change of the vehicle's speed and the response time of the accelerator and brake;

[0080] Perform simulation runs on virtual models to verify the effects of acceleration or deceleration instructions;

[0081] If the simulation results show that the instruction may lead to an unsafe situation, the instruction is optimized and adjusted;

[0082] The optimized instructions are applied to the vehicle's speed control system to make the vehicle move.

[0083] To further illustrate, the current speed v cur With V final Compare and calculate the speed difference Δv for subsequent instruction generation, expressed as,

[0084] Δv=V final -v cur

[0085] Among them, v cur is the current speed of the vehicle, and Δv represents the difference between the current speed and the target speed, which will be used to determine whether acceleration or deceleration is required.

[0086] Based on the calculated speed difference Δv, a preliminary acceleration or deceleration instruction a is generated. raw If Δv>0, an acceleration instruction is generated; if Δv<0, a deceleration instruction is generated.

[0087] Preliminary Instructionsa raw The calculation is expressed as,

[0088] a raw =k a ·Δv

[0089] Among them, k a is the acceleration or deceleration factor, reflecting the responsiveness of the vehicle's powertrain. It depends on factors such as the type of vehicle, current load, and road conditions. Δv is the speed difference, which is used to determine whether the vehicle needs to accelerate or decelerate. raw It is the initial acceleration or deceleration command generated, which directly reflects the requirements of vehicle operation due to the speed difference.

[0090] Preliminary Instructionsa raw After generation, the commands are adjusted to ensure smooth changes in vehicle speed, taking into account the vehicle's dynamic characteristics, the response time of the accelerator and brakes.

[0091] Current speed change rate The calculation is expressed as,

[0092]

[0093] Among them, v prev is the speed of the vehicle at the previous moment, v cur is the current speed, Δt is the time interval between two speed measurement moments, Indicates how fast the current vehicle speed changes, and is used to determine whether the vehicle needs to make smoother speed adjustments.

[0094] Smoothing formula a smooth It is expressed as,

[0095]

[0096] Response time adjusted instruction a adj It is expressed as,

[0097]

[0098] Among them, t acc and t brkare the response times of the accelerator and brake, respectively, and a adj It is an instruction adjusted according to the vehicle response characteristics to ensure that the time response of the instruction execution will not affect the vehicle's driving stability.

[0099] Before the instruction is actually executed, the virtual model is used to simulate the instruction and pre-check the feasibility of the acceleration or deceleration instruction. Possible risks. If the risk factor R sim If the safety threshold is exceeded, the instruction is optimized and adjusted.

[0100] Risk factor R in simulation operation sim It is expressed as,

[0101]

[0102] Among them, S w is the road slipperiness, indicating the current slippery condition of the road surface. The higher the slipperiness, the lower the risk factor, and vice versa. brake is the instantaneous braking distance, calculated as Where τ is the friction coefficient of the road surface and g is the acceleration due to gravity. safe is the safe braking distance, which is used to compare the actual braking distance to assess the risk. w is the tire temperature, is the optimal operating temperature of the tire. and are the maximum and minimum operating temperature ranges of the tire, respectively. Temperature deviation will affect the tire's grip and vehicle safety, and A1, A2, and A3 represent weight factors, respectively.

[0103] The final instruction after optimization is a opt It is expressed as,

[0104]

[0105] Among them, a opt It is an optimized instruction that takes into account the risks identified during the simulation process to ensure that the vehicle can still drive safely in complex environments.

[0106] If R sim Not exceeding R max , a opt =a adj .

[0107] The final generated acceleration or deceleration instruction a opt It is transmitted to the vehicle's speed control system, and the vehicle adjusts its speed based on the instruction.

[0108] Ensure that the vehicle speed approaches V smoothly. final, and drive within a safe range.

[0109] The vehicle speed adjustment equation is expressed as,

[0110] v next =v cur +a opt ·Δt

[0111] Among them, v next is the expected speed of the vehicle in the next time period, a opt It is an optimized acceleration or deceleration instruction to ensure smooth and safe speed adjustment of the vehicle.

[0112] It should be further explained that, in passenger and freight scenarios, the technical solution of the present invention realizes accurate processing of speed limit information and dynamic adjustment of driving speed through the application of double locking mechanism and virtual model, which significantly improves the safety and efficiency of the system.

[0113] First, in freight scenarios, the transported goods may be dangerous goods or high-value goods, and the accurate acquisition and timely application of speed limit information are crucial to driving safety. The present invention uses a double-lock mechanism to ensure that after the first thread obtains the speed limit information from the communication module, it can activate the write lock before the data is completely written to the cache area, preventing the second thread from reading the data when it is not yet complete. This avoids erroneous speed threshold calculations due to incomplete data. In passenger scenarios, passenger safety and comfort are key indicators. Through the double-lock mechanism, the system can ensure the timely update of speed limit information, ensuring that when the path changes, the system can respond quickly and dynamically adjust the speed of the vehicle to avoid affecting passenger safety in the event of sudden speed limit adjustments or path deviations.

[0114] Secondly, the application of virtual models in the generation of acceleration or deceleration instructions ensures the optimal effect in freight and passenger scenarios. In the freight scenario, the system uses a virtual model to simulate the acceleration or deceleration behavior of the vehicle based on the vehicle's load, the type of cargo, and the road conditions. When a heavy-loaded truck needs to decelerate, the system pre-simulates the execution effect of the deceleration instruction through a virtual model to ensure that the brake response time is smooth enough to avoid displacement or damage to the cargo due to sudden braking. In the passenger scenario, the system will consider the number of passengers and the real-time speed of the vehicle, and use the virtual model to optimize the generated acceleration or deceleration instructions to ensure that the acceleration changes of the vehicle will not cause discomfort to the passengers, ensuring that the vehicle runs smoothly while improving the passenger experience.

[0115] In addition, under complex road conditions, the technical solution of the present invention can dynamically adjust the speed limit information to cope with the ever-changing traffic environment. For example, in mountain transportation, the system dynamically adjusts the vehicle's speed threshold based on real-time speed limit information, road curvature, slope and other data. In freight scenarios, the system can prevent vehicles from speeding on downhill sections and achieve safe passage on sharp bends; in passenger scenarios, the system can reduce passenger discomfort when going uphill, downhill and on sharp bends by smoothly adjusting the vehicle speed.

[0116] It should be further explained that the present invention generates acceleration or deceleration instructions by calculating the speed threshold and combining it with the current speed, rather than just directly using the calculated threshold for adjustment. The reason for this design is to better adapt to the complex and changeable actual driving environment, thereby providing a safer and smoother driving experience.

[0117] Although it is simple to directly use the speed threshold for adjustment, this method ignores the current dynamic state of the vehicle. The inertia and response time of the vehicle are different in different acceleration or deceleration states. Simply using the threshold may cause the vehicle speed adjustment to be not smooth enough, and may even cause sudden speed changes of the vehicle, which is very dangerous in passenger or freight transportation. By comparing the speed threshold with the current speed, the system can generate more accurate acceleration or deceleration instructions based on the real-time state of the vehicle, thereby avoiding the above risks.

[0118] The vehicle may be affected by the external environment during driving, such as the curvature and slope of the road, changes in traffic signals, and real-time traffic conditions. These factors will directly affect the driving stability and safety of the vehicle. By calculating the current speed change rate and considering the response time of the accelerator and brake, the system can generate instructions that are more suitable for the current road conditions, making the vehicle speed adjustment more flexible and safer.

[0119] The introduction of virtual models provides additional safety guarantees for command generation. By simulating the generated commands, the execution effect of the commands can be predicted in advance, and optimization and adjustment can be made when potential safety hazards are found. This prevents the commands ultimately applied to the vehicle from causing sudden speed changes or causing the vehicle to lose control, thus improving safety.

[0120] By comprehensively considering the dynamic characteristics of the vehicle and changes in the external environment, the system can make the optimal speed adjustment under different driving conditions. This not only improves the driving safety of the vehicle, but also reduces the operating burden of the driver and improves the overall driving experience.

[0121] It should be noted that if the calculated result of any speed value exceeds the scope of the current road section speed limit information, the system will automatically trigger the speed limit adjustment mechanism. This mechanism automatically adjusts the calculated speed threshold to make it consistent with the boundary value of the maximum or minimum speed limit of the current road section by real-time monitoring the difference between the current vehicle speed and the road section speed limit range, and voice broadcasts the current road section speed limit information to remind.

[0122] Specifically, if the calculated result exceeds the maximum speed limit of the current section of road, the system will forcibly adjust it to the maximum speed limit of the section; if the calculated result is lower than the minimum speed limit, the system will forcibly adjust it to the minimum speed limit of the section.

[0123] Embodiment 3, an embodiment of the present invention, is different from the first two embodiments in that:

[0124] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0125] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0126] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0127] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0128] Example 4 is an embodiment of the present invention, which provides a method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system. In order to verify the beneficial effects of the present invention, a scientific demonstration is carried out through simulation experiments.

[0129] The experiment set up three scenarios, among which scenario 1 is a mountain road. This scenario selected a mountain road located above 1,000 meters above sea level, with a total length of 15 kilometers and many steep slopes and sharp turns. The slope of the road varies greatly, with the maximum slope reaching 12%. There are guardrails and partial vegetation coverage on both sides of the road. The road surface is slippery but without snow. The test vehicle will drive at a speed close to the speed limit in this scenario to simulate the impact of complex terrain on vehicle speed and path.

[0130] Scene 2 is an urban road. This scene is set in a busy section of the city. The length of the section is 8 kilometers, including a 500-meter tunnel and two bridges. There is a temporary construction area in the tunnel with a speed limit of 30km / h. The bridge section has some road damage and the speed limit is 40km / h. There are dense traffic lights on this section, and vehicles need to start and stop frequently. The traffic flow is large and congestion is serious during peak hours. During the experiment, the response speed and path correction ability of the vehicle in a complex urban traffic environment will be monitored.

[0131] Scenario 3 is a highway. The highway scenario is 30 kilometers long, including a long straight section and multiple continuous curves. On the day of the test, there was a sudden heavy rain, visibility was reduced, and the road surface was slippery. The speed limit information indicated a maximum speed limit of 120km / h and a minimum speed limit of 60km / h. In this scenario, the experimental vehicle will travel at a higher speed to examine the system's ability to respond to sudden weather and complex road conditions during high-speed driving.

[0132] The traditional test system and the system of the present invention are installed on two test vehicles respectively. The traditional system adopts a fixed speed limit GPS navigation solution. Vehicle 1 is a passenger bus, fully loaded with 55 passengers and a total load of 20 tons; Vehicle 2 is a heavy freight truck, fully loaded with construction materials and a total load of 40 tons. To ensure the comprehensiveness of data collection, the vehicles are equipped with road slippery sensors, tire temperature monitoring devices and real-time data acquisition equipment to record key data such as vehicle speed, acceleration, path deviation, braking distance, etc. After the test environment is arranged, the vehicle will be tested in three scenarios in turn.

[0133] The test vehicles were tested using the traditional system and the system of the present invention in each scenario, and three tests were conducted in each scenario to ensure the reliability of the data. Vehicle 1 and Vehicle 2 drove along the set route, starting from the same location for each test and driving to the end point, recording key data such as the number of real-time speed limit adjustments, vehicle speed, number of path deviations, braking response time, and acceleration and deceleration command generation time. All data will be stored in the central data collector for subsequent analysis.

[0134] Data analysts collated the test data in each scenario and generated tables to record the performance of the traditional system and the system of the present invention in different scenarios. The data included key indicators such as the number of real-time speed limit adjustments, the number of path deviations, the average speed change rate, the braking response time, and the safety assessment score. After the data recording was completed, the data analysis phase was entered to specifically compare the performance differences of the two systems under complex road conditions. The experimental results are shown in Tables 1, 2, and 3.

[0135] Table 1 Comparison of performance on mountain roads

[0136]

[0137]

[0138] Table 2 Comparison of performance in urban roads

[0139] project Traditional systems System of the present invention Real-time speed limit adjustment times 15 40 Path deviation times 7 2 Average speed change rate (km / h / s) 1.2 0.7 Brake response time (ms) 250 180 Safety Assessment Score 70 85

[0140] Table 3 Comparison of performance on highways

[0141] project Traditional systems System of the present invention Real-time speed limit adjustment times 12 35 Path deviation times 4 1 Average speed change rate (km / h / s) 1 0.6 Brake response time (ms) 220 160 Safety Assessment Score 80 95

[0142] The system of the present invention exhibits a higher frequency of real-time speed limit adjustment in all scenarios. The multi-threaded architecture and dual-lock mechanism enable the system of the present invention to obtain and process speed limit information in real time, and quickly adjust the speed threshold of the vehicle. In contrast, the traditional system uses a fixed speed limit mechanism, and the speed limit adjustment frequency is low, resulting in an inability to respond in time under complex road conditions, increasing the risk of speeding or underspeed. In terms of the number of path deviations, the system of the present invention performed better than the traditional system in the test. The accuracy of the path planning and correction functions enables the system of the present invention to monitor the position of the vehicle in real time, and correct the driving direction in time to reduce path deviation. The path planning and correction functions of the traditional system are lagging, especially under complex road conditions, and the vehicle is prone to deviate from the intended route.

[0143] Comparison of vehicle speed change rates shows that the system of the present invention performs more smoothly during speed adjustment. The system of the present invention generates optimized acceleration or deceleration instructions by comprehensively considering the driving difficulty coefficient, real-time speed limit information and vehicle dynamic characteristics to ensure the smoothness of speed adjustment. Due to the lack of dynamic adjustment capability, the speed change rate of traditional systems is relatively large, resulting in insufficient smoothness in vehicle speed adjustment. The braking response time of the system of the present invention is shorter than that of traditional systems, indicating that the speed limit threshold adjustment and speed control of the system of the present invention are more precise. Real-time speed limit adjustment and simulated operation of the virtual model enable the system of the present invention to quickly generate and execute optimized braking instructions, shorten the braking response time, and enhance driving safety. The braking response time of traditional systems is relatively long, which may result in untimely braking.

[0144] In terms of safety assessment scores, the system of the present invention can dynamically adjust the vehicle's speed according to the specific conditions of the current road section through precise speed limit management. It not only reduces the risk of speeding or underspeed, but also ensures that the vehicle always stays within a safe speed range in complex road conditions. The system of the present invention demonstrates excellent accuracy in path planning. By monitoring the vehicle's geographic location in real time, the system of the present invention can quickly provide correction guidance when the vehicle deviates from the predetermined path, significantly reducing the occurrence of path deviation and reducing the potential danger caused by deviation from the path.

[0145] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A passenger and freight GPS system, characterized in that: include: Positioning module, navigation module, code module and communication module; The positioning module is used to obtain and provide the geographical location information of the vehicle in real time; The navigation module is used to plan the optimal path according to the current position of the vehicle and provide correction guidance when the vehicle deviates from the path; The code module is used to dynamically obtain road section speed limit information, analyze and adjust the vehicle speed limit threshold in real time, the speed limit information includes the maximum speed limit and the minimum speed limit; The communication module exchanges data with the external navigation system in real time.

2. The passenger and freight GPS system according to claim 1, characterized in that: The code module adopts a dual-thread architecture; The dual-thread architecture includes a first thread and a second thread; The first thread is used to obtain real-time road speed limit data from the communication module; The second thread is used to parse the road section speed limit data and perform speed limit adjustment according to the path information provided by the navigation module and the current position provided by the positioning module.

3. A method for dynamically identifying and adjusting the speed limit threshold of a road section using the passenger and freight GPS system as claimed in any one of claims 1 to 2, characterized in that: include: The positioning module obtains the real-time geographic location information of the vehicle and synchronously transmits the geographic location information to the navigation module and the code module; The navigation module calculates the optimal driving path of the vehicle based on the current position data provided by the positioning module and passes the path information to the code module; During the driving process, the navigation module continuously monitors the position of the vehicle. When the vehicle deviates from the planned path, the navigation module provides deviation correction guidance to ensure that the vehicle drives along the planned path. The communication module exchanges data with the external navigation system in real time, obtains the speed limit information of the current road section and transmits it to the first thread of the code module; Initialize the code module, start the dual-lock mechanism to coordinate dual-thread operation, the first thread receives the speed limit information of the current road section from the communication module, activates the write lock before writing the speed limit information into the cache area, and when the speed limit information is completely written, the write lock is released, allowing the second thread to read the speed limit information; Start the second thread and activate the read lock. After reading the speed limit information, the second thread combines the path information provided by the navigation module and the current position provided by the positioning module to parse and determine the speed threshold. When the speed limit information is parsed, the read lock is released, and the first thread continues to obtain new speed limit information and write it into the cache area; The second thread determines an acceleration or deceleration instruction according to the speed threshold, and applies the acceleration or deceleration instruction to a speed control system of the vehicle.

4. The method for dynamically identifying and adjusting the road speed limit threshold of a passenger and freight GPS system as claimed in claim 3, characterized in that: The initialization code module includes executing initialization operations, allocating memory resources, and allocating independent cache areas for the first thread and the second thread respectively. The cache area of ​​the first thread is used to store speed limit information; the cache area of ​​the second thread is used to store parsed speed limit information, vehicle real-time speed, path information and location information.

5. The method for dynamically identifying and adjusting the road speed limit threshold of a passenger and freight GPS system as claimed in claim 4, characterized in that: The analyzing and determining the speed threshold includes calculating the driving difficulty coefficient of the current path, adjusting the speed limit information in combination with the driving difficulty coefficient, and generating a preliminary speed threshold; The second thread analyzes the real-time speed, acceleration and current position of the vehicle, dynamically adjusts the preliminary speed threshold, and finally determines the speed threshold.

6. The method for dynamically identifying and adjusting the road speed limit threshold of a passenger and freight GPS system as claimed in claim 5, characterized in that: The speed threshold is expressed as: Where D represents the driving difficulty coefficient of the current path, R represents the curvature radius of the road, P represents the slope of the current road, and P r represents the reference road slope, m represents the total mass of the vehicle, g represents the gravitational acceleration constant, h g Indicates the height of the vehicle's center of gravity, I z represents the moment of inertia of the vehicle, μ represents the comprehensive traffic complexity coefficient of the path, T represents the influencing factor of the real-time traffic conditions, and T r represents the benchmark traffic condition, V max is the maximum speed limit of the current road section, V min is the minimum speed limit, α is the adjustment factor that controls the impact of the driving difficulty coefficient on the speed threshold, and v cur is the current speed, γ1 and γ2 are factors used to adjust the effects of acceleration and speed.

7. The method for dynamically identifying and adjusting the road speed limit threshold of a passenger and freight GPS system as claimed in claim 6, characterized in that: The method of determining the acceleration or deceleration instruction according to the speed threshold includes, during the vehicle driving process, parsing the speed threshold through the second thread, comparing the speed threshold with the current speed of the vehicle to determine whether acceleration or deceleration is required, and generating the acceleration or deceleration instruction according to the comparison result.

8. The method for dynamically identifying and adjusting the road speed limit threshold of a passenger and freight GPS system as claimed in claim 7, characterized in that: The generating of the acceleration or deceleration instruction includes generating an acceleration instruction if the current speed is lower than the speed threshold; generating a deceleration instruction if the current speed is higher than the speed threshold; Adjusting the generated command taking into account the rate of change of the vehicle's speed and the response time of the accelerator and brake; Perform simulation runs on virtual models to verify the effects of acceleration or deceleration instructions; If the simulation results show that the instruction may lead to an unsafe situation, the instruction is optimized and adjusted; The optimized instructions are applied to the vehicle's speed control system to make the vehicle move.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system according to any one of claims 3 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for dynamically identifying and adjusting the speed limit threshold of a road section in a passenger and freight GPS system according to any one of claims 3 to 7 are implemented.

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