Automobile navigation method, method for determining engine shutdown position and related device

Abstract

An embodiment of the present invention provides a car navigation method, a method for determining a flameout position, and related devices, which relate to the field of vehicle navigation technology. The car navigation method: first, if no satellite positioning information is received when the car is started, a data frame recording the flameout position of the car is obtained, wherein the flameout position is the positioning data when the car enters the flameout state that meets the preset conditions or is calculated based on the positioning data of multiple moments before the car enters the flameout state; then, if the data frame meets the preset verification conditions, the flameout position recorded in the data frame is used as the first starting position, so that the car can be navigated based on the first starting position determined by the flameout position in the absence of satellite positioning information.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle navigation, and in particular to a vehicle navigation method, an ignition-off position determination method and related devices. Background Art

[0002] When a car is started in a scenario where the Global Navigation Satellite System (GNSS) signal is weak or even no signal (such as a garage, tunnel, etc.), the car cannot obtain satellite positioning information, and the positioning service of the on-board navigation system cannot be used until the car drives to an open location with good signal.

[0003] In this regard, most of the current in-vehicle navigation systems can support inertial navigation to provide navigation services for car drivers in the absence of satellite positioning information. Since inertial navigation needs to know the accurate starting position to calculate the position information of the car when it is driving without satellite positioning information, so as to guide the driver to drive safely, therefore, an accurate and reliable starting position can effectively improve the safety of the car when driving without external positioning signals and meet the user's requirements for improving driving experience. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a car navigation method, a method for determining a flameout position and related devices, which can accurately determine the flameout position of the car when the car enters a flameout state, so that when the car is started again, the car can be navigated based on the navigation starting position determined by the flameout position in the absence of satellite positioning information.

[0005] The technical solution provided by the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a car navigation method, which is applied to a main control chip in a car navigation system, and the method comprises:

[0007] If no satellite positioning information is received when the car is started, a data frame recording the shutdown position of the car is obtained;

[0008] The flameout position is the positioning data of the vehicle when it enters the flameout state that meets the preset conditions or is calculated based on the positioning data of multiple moments before the vehicle enters the flameout state;

[0009] If the data frame meets the preset verification condition, the ignition-off position recorded in the data frame is used as the first starting position, so as to navigate the vehicle based on the first starting position.

[0010] Optionally, the vehicle navigation system further includes an inertial element, the main control chip is electrically connected to the inertial element, and the method further includes:

[0011] At each driving moment after the vehicle is started, inertial navigation data of the vehicle is obtained from the inertial element;

[0012] Calculating the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment;

[0013] The vehicle is navigated according to the dead reckoning data of the vehicle at each driving moment.

[0014] Optionally, the step of calculating the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment comprises:

[0015] Using the first starting position as dead reckoning data of the vehicle at the start time;

[0016] For each of the driving moments after the start moment, the dead reckoning data of the vehicle at the driving moment is determined according to the inertial navigation data of the vehicle at the driving moment and the dead reckoning data of the vehicle at a moment before the driving moment.

[0017] Optionally, the method further comprises:

[0018] During navigation of the vehicle, if the satellite positioning information is received, determining a second starting position according to the satellite positioning information and dead reckoning data of the vehicle at the time of receiving the satellite positioning information;

[0019] Calculate the fused positioning data of the vehicle at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the vehicle acquired at each driving moment;

[0020] The car is navigated according to the fused positioning data of the car at each driving moment.

[0021] Optionally, the step of determining the second starting position according to the satellite positioning information and the dead reckoning data of the vehicle at the time of receiving the satellite positioning information comprises:

[0022] Calculating a position offset between the satellite positioning information and the dead reckoning data at the receiving time;

[0023] If the position offset is greater than a preset offset value, using the satellite positioning information as the second starting position;

[0024] If the position offset is not greater than a preset offset value, determining a first weight of the satellite positioning information and a second weight of the dead reckoning data at the receiving time according to the size of the position offset;

[0025] Based on the first weight and the second weight, a weighted sum is performed on the satellite positioning information and the dead reckoning data at the receiving time to obtain the second starting position.

[0026] Optionally, the satellite positioning information includes a first longitude and a first latitude, and the dead reckoning data includes a second longitude and a second latitude;

[0027] The step of calculating the position offset between the satellite positioning information and the dead reckoning data at the receiving time comprises:

[0028] respectively calculating a first difference between the first longitude and the second longitude, and a second difference between the first latitude and the second latitude;

[0029] The maximum value of the absolute value of the first difference and the absolute value of the second difference is used as the position offset.

[0030] Optionally, the step of calculating the fused positioning data of the vehicle at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the vehicle acquired at each driving moment comprises:

[0031] Using the second starting position as fused positioning data at the moment when the vehicle first receives the satellite positioning information;

[0032] For each driving moment after the moment when the satellite positioning information is first received, the fused positioning data of the car at the driving moment is determined based on the satellite positioning information at the driving moment, the inertial navigation data of the car at the driving moment, and the fused positioning data of the car at the moment before the driving moment.

[0033] Optionally, the step of determining the fused positioning data of the vehicle at the driving time according to the satellite positioning information at the driving time, the inertial navigation data of the vehicle at the driving time, and the fused positioning data of the vehicle at a moment before the driving time includes:

[0034] Performing an integral operation on the inertial navigation data of the vehicle at the driving moment and the fused positioning data of the vehicle at a moment before the driving moment to obtain a calculation result;

[0035] Based on preset weights, a weighted sum is performed on the calculation result and the satellite positioning information received at the driving time to obtain fused positioning data of the car at the driving time.

[0036] Optionally, the vehicle navigation system further includes a positioning counter electrically connected to the main control chip, and the method further includes:

[0037] During the driving process of the vehicle, the type of positioning data of the vehicle is obtained at preset time intervals;

[0038] For the type of the positioning data obtained each time, if the type of the positioning data is fused positioning data, accumulating the value of the positioning counter;

[0039] If the type of the positioning data is dead reckoning data and the positioning data converges, accumulating the value of the positioning counter;

[0040] If the type of the positioning data is dead reckoning data and the positioning data does not converge, the value of the positioning counter is not accumulated;

[0041] The value of the positioning counter is used to determine whether the positioning data when the vehicle enters the ignition-off state meets a preset condition, and when the positioning data meets the preset condition, the positioning data is determined as the ignition-off position.

[0042] Optionally, before the step of using the ignition-off position recorded in the data frame as the inertial navigation starting position if the data frame satisfies the preset verification condition, a step of determining whether the data frame satisfies the preset verification condition is further included, which includes:

[0043] intercepting a preset field in the data frame;

[0044] If the value of the preset field is a preset check value, it is determined that the data frame meets the preset check condition.

[0045] In a second aspect, the present invention provides a method for determining an engine shutdown position, which is applied to a main control chip in a vehicle navigation system, and the method comprises:

[0046] Acquire the positioning data of the vehicle when it enters the engine-off state, and determine whether the positioning data meets a preset condition;

[0047] If the positioning data meets the preset condition, the positioning data is used as the flameout position;

[0048] If the positioning data does not meet the preset conditions, the flameout position is calculated based on the positioning data at multiple moments before the vehicle enters the flameout state;

[0049] Wherein, the ignition-off position is used to determine the inertial navigation starting position when the main control chip executes the automobile navigation method as described in the first aspect;

[0050] Generate a data frame recording the ignition off position, and store the data frame. Optionally, the step of determining whether the positioning data meets a preset condition includes:

[0051] Obtaining the value of the positioning counter when the vehicle is in an ignition-off state;

[0052] If the value of the positioning counter is greater than a preset threshold, it is determined that the positioning data meets a preset condition;

[0053] If the value of the positioning counter is not greater than a preset threshold, it is determined that the positioning data does not meet a preset condition.

[0054] In a third aspect, the present invention provides a car navigation device, which is applied to a main control chip in a car navigation system, and the device comprises:

[0055] The first processing module is used for:

[0056] If no satellite positioning information is received when the car is started, a data frame recording the shutdown position of the car is obtained;

[0057] The flameout position is the positioning data of the vehicle when it enters the flameout state that meets the preset conditions or is calculated based on the positioning data of multiple moments before the vehicle enters the flameout state;

[0058] Navigation module for:

[0059] If the data frame meets the preset verification condition, the ignition-off position recorded in the data frame is used as the first starting position, so as to navigate the vehicle based on the first starting position.

[0060] In a fourth aspect, the present invention provides a device for determining an ignition off position, which is applied to a main control chip in a vehicle navigation system, and the device comprises:

[0061] Get modules for:

[0062] Acquiring positioning data when the vehicle enters an engine-off state;

[0063] The second processing module is used for:

[0064] Determining whether the positioning data meets a preset condition;

[0065] If the positioning data meets the preset condition, the positioning data is used as the flameout position;

[0066] If the positioning data does not meet the preset conditions, the flameout position is calculated based on the positioning data at multiple moments before the vehicle enters the flameout state;

[0067] The ignition-off position is used to determine a first starting position when the main control chip executes the automobile navigation method as described in the first aspect above;

[0068] A data frame recording the ignition-off position is generated and the data frame is stored.

[0069] In a fifth aspect, the present invention provides a main control chip, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the car navigation method as described in the first aspect above, and / or the method for determining the ignition off position as described in the second aspect above.

[0070] In a sixth aspect, the present invention provides a vehicle-mounted navigation system, comprising the main control chip as described in the fifth aspect.

[0071] In a seventh aspect, the present invention provides a computer-readable storage medium storing a computer program, wherein when the computer program is processed and executed, the car navigation method as described in the first aspect above and / or the method for determining the ignition off position as described in the second aspect above are implemented.

[0072] Compared with the prior art, the embodiments of the present invention provide a car navigation method, a method for determining the flameout position, and related devices. First, if the satellite positioning information is not received when the car is started, a data frame recording the flameout position of the car is obtained, wherein the flameout position is the positioning data when the car enters the flameout state that meets the preset conditions or is calculated based on the positioning data of multiple moments before the car enters the flameout state; then, if the data frame meets the preset verification conditions, the flameout position recorded in the data frame is used as the first starting position to navigate the car based on the first starting position. Because the embodiments of the present invention accurately determine the flameout position of the car when the car is in the flameout state, when the car is started again, the car can be navigated based on the first starting position determined by the flameout position in the absence of satellite positioning information.

[0073] Other features and advantages of the present invention will be described in the subsequent description, or some features and advantages can be inferred or determined without doubt from the description, or can be learned by implementing the above-mentioned technical features of the present invention and can be implemented according to the contents of the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0075] Figure 1 A schematic block diagram of the structure of a vehicle navigation system provided by an embodiment of the present invention;

[0076] Figure 2 A schematic block diagram of the structure of a main control chip provided by an embodiment of the present invention;

[0077] Figure 3 A schematic diagram of a process of a car navigation method provided by an embodiment of the present invention Figure 1 ;

[0078] Figure 4 A schematic diagram of a process of a car navigation method provided by an embodiment of the present invention Figure 2 ;

[0079] Figure 5 A flowchart of an implementation method of step S104 provided in an embodiment of the present invention;

[0080] Figure 6 An example of a car navigation process provided by an embodiment of the present invention Figure 1 ;

[0081] Figure 7 A schematic diagram of a process of a car navigation method provided by an embodiment of the present invention Figure 3 ;

[0082] Figure 8 A flowchart of an implementation method of step S106 provided in an embodiment of the present invention;

[0083] Fig. 9 A flowchart of an implementation method of step S107 provided in an embodiment of the present invention;

[0084] Fig.10 An example of a car navigation process provided by an embodiment of the present invention Figure 2 ;

[0085] Fig.11 A schematic diagram of a process of a car navigation method provided by an embodiment of the present invention Figure 4 ;

[0086] Fig.12 A schematic flow chart of a method for determining an off position provided in an embodiment of the present invention;

[0087] Fig.13 A functional unit block diagram of a car navigation device provided by an embodiment of the present invention;

[0088] Fig.14 A block diagram of functional units of a device for determining an ignition failure position provided by an embodiment of the present invention.

[0089] Icons: 100 - vehicle navigation system; 110 - main control chip; 111 - memory; 112 - processor; 120 - positioning counter; 130 - external memory; 140 - inertial element; 200 - vehicle navigation device; 201 - first processing module; 202 - navigation module; 203 - update module; 300 - ignition off position determination device; 301 - acquisition module; 302 - second processing module. DETAILED DESCRIPTION

[0090] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0091] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0092] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0093] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0094] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0095] In order to provide accurate navigation services to the car in the absence of satellite positioning information to ensure safe driving, the embodiments of the present invention provide a car navigation method, an ignition off position determination method and related devices, which are described in detail below.

[0096] First, an in-vehicle navigation system 100 provided by an embodiment of the present invention is introduced.

[0097] Please refer to Figure 1 The vehicle navigation system 100 includes a main control chip 110 , and a positioning counter 120 , an external memory 130 and an inertial element 140 electrically connected to the main control chip 110 .

[0098] like Figure 2 As shown, the main control chip 110 may include a memory 111 and a processor 112 .

[0099] Among them, the processor 112 can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the car navigation method provided by the following method embodiments and / or the method for determining the ignition position.

[0100] The memory 111 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 111 may exist independently and be connected to the processor 112 via a communication bus. The memory 111 may also be integrated with the processor 112. Among them, the memory 111 is used to store machine executable instructions for executing the scheme of the present invention. The processor 112 is configured to execute machine executable instructions stored in the memory 111 to implement the following method embodiments.

[0101] The positioning counter 120 can be a sequential logic circuit, which is composed of a basic counting unit and some control gates. The counting unit is composed of a series of various triggers with information storage functions, such as RS trigger, T trigger, D trigger and JK trigger.

[0102] The external memory 130 is used to store the flameout position, which can be a memory other than the main control chip 110, such as a magnetic medium or an optical disk. Optionally, in the embodiment of the present invention, in order to ensure that the flameout position can be repeatedly erased and written and burned at high speed, the external memory can also be set in the corresponding address of the electrically erasable programmable read-only memory (Electrically ErasableProgrammabler-Only MEMory, EEPROM) peripheral to ensure that the storage location does not overlap with the program storage area, ensuring that the access to the flameout position does not affect the normal operation of the main program.

[0103] The inertial element 140 may be an accelerometer or an angular velocity meter, which can measure inertial navigation data such as acceleration and angular velocity during the driving of the vehicle.

[0104] The following is an introduction to a car navigation method provided by an embodiment of the present invention. The execution subject of the car navigation method is Figure 1 The main control chip 110 in.

[0105] Please refer to Figure 3 The car navigation method includes steps S101 to S102.

[0106] S101, if no satellite positioning information is received when the car is started, a data frame recording the shutdown position of the car is obtained.

[0107] The flameout position is the positioning data when the vehicle meets the preset conditions and enters the flameout state, or is calculated based on the positioning data at multiple moments before the vehicle enters the flameout state.

[0108] In a possible implementation, the preset condition may mean that the value of the positioning counter is greater than a set value when the vehicle enters an ignition-off state, and the value of the positioning counter is updated based on the type and convergence of the positioning data at each driving moment during the vehicle's driving process.

[0109] In another possible implementation, the preset condition may refer to the time difference between the time when the vehicle is turned off and the time when the vehicle is started, that is, the driving time, reaching a set value.

[0110] S102: If the data frame meets a preset verification condition, the ignition-off position recorded in the data frame is used as a first starting position, so as to navigate the vehicle based on the first starting position.

[0111] Among them, since the data frame can be cached in the external memory, in order to ensure that the ignition off position read from the external memory is consistent with the ignition off position previously written into the external memory, it is necessary to determine whether the data frame meets the preset verification condition.

[0112] It can be understood that before executing step S102, it is necessary to execute the step of "determining whether the data frame meets the preset verification condition".

[0113] Optionally, the execution process of this step is as follows:

[0114] First, intercept the preset fields in the data frame;

[0115] Then, if the value of the preset field is a preset check value, it is determined that the data frame meets the preset check condition.

[0116] The preset field is a field pre-designated in the data frame for recording a preset check value. When the value of the preset field is the preset check value, the data frame meets the preset check condition, and it can be determined that the flameout position read from the external memory is consistent with the flameout position previously written to the external memory.

[0117] The following will introduce how to navigate a car based on the first starting position.

[0118] exist Figure 3 Based on Figure 4 , the car navigation method also includes steps S103 to S105.

[0119] S103, at each driving moment after the vehicle is started, the inertial navigation data of the vehicle is obtained from the inertial element.

[0120] The unit of the driving time can be set as needed. For example, every second can be regarded as a driving time. The inertial navigation data includes the acceleration and angular velocity of the vehicle.

[0121] S104, calculating the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment.

[0122] like Figure 5 As shown, step S104 includes sub-steps S104-1 to S104-2.

[0123] S104-1, using the first starting position as the dead reckoning data of the vehicle at the start time.

[0124] It is understandable that, at the start-up time, the car has not moved yet, so the first starting position can be regarded as the dead reckoning data of the car at this time.

[0125] S104-2, for each driving moment after the start time, determining the dead reckoning data of the vehicle at the driving moment according to the inertial navigation data of the vehicle at the driving moment and the dead reckoning data of the vehicle at a moment before the driving moment.

[0126] In the embodiment of the present invention, for each driving moment, the inertial navigation data of the vehicle at the driving moment and the dead reckoning data at the previous driving moment are integrated, and the obtained calculation result is used as the dead reckoning data of the vehicle at the driving moment.

[0127] S105, navigating the car according to the dead reckoning data of the car at each driving moment.

[0128] like Figure 6 As shown, the first starting position of the car is S0. For the driving time 6, the dead reckoning data S6 is obtained by integrating the dead reckoning data S5 at the driving time 5 and the inertial navigation data a6 of the car at the driving time 6. At the driving time 6, the car is navigated according to the dead reckoning data S6, so that the car can drive normally without satellite positioning information.

[0129] The following is a detailed description of the situation in which satellite positioning information is received during car navigation.

[0130] exist Figure 4 Based on Figure 7 The car navigation method also includes steps S106 to S108.

[0131] S106, during the process of navigating the vehicle, if satellite positioning information is received, a second starting position is determined according to the satellite positioning information and the dead reckoning data of the vehicle at the time of receiving the satellite positioning information.

[0132] If the car is in a basement or tunnel when it starts, it is difficult for it to receive satellite positioning information. However, after the car leaves the basement or tunnel, it can receive satellite positioning information normally. After the car receives the satellite positioning signal again, it needs to continue navigation based on the satellite positioning information.

[0133] like Figure 8 As shown, step S106 includes sub-steps S106-1 to S106-4.

[0134] S106-1, calculating the position offset between the satellite positioning information and the dead reckoning data at the receiving time.

[0135] The satellite positioning information includes a first longitude and a first latitude, and the dead reckoning data includes a second longitude and a second latitude.

[0136] Optionally, the implementation process of step S106-1 may be as follows:

[0137] First, a first difference between the first longitude and the second longitude, and a second difference between the first latitude and the second latitude are calculated respectively;

[0138] Then, the maximum value of the absolute value of the first difference and the absolute value of the second difference is taken as the position offset.

[0139] S106-2: If the position offset is greater than the preset offset value, the satellite positioning information is used as the second starting position.

[0140] The preset offset value represents the upper limit of the deviation between the real position of the vehicle and the dead reckoning data at the receiving time, and the preset offset value can be set by setting a test experiment of the vehicle navigation system.

[0141] It can be understood that when the position offset is greater than the preset offset value, it means that the dead reckoning data at the time of reception deviates too much from the actual position of the vehicle. In this case, the first longitude and the first latitude included in the satellite positioning information can be directly used as the longitude and latitude of the second starting position.

[0142] S106-3: If the position offset is not greater than the preset offset value, determine the first weight of the satellite positioning information and the second weight of the inertial navigation positioning data at the receiving moment according to the size of the position offset.

[0143] When the position offset is less than or equal to the preset offset value, it means that the deviation of the dead reckoning data at the receiving moment compared with the actual position of the vehicle is within an acceptable range.

[0144] The size of the first weight of the satellite positioning information is proportional to the size of the position offset, and the size of the second weight of the dead reckoning data at the reception time is inversely proportional to the size of the position offset. That is, the larger the position offset, the larger the first weight and the smaller the second weight. Conversely, the smaller the position offset, the smaller the first weight and the larger the second weight.

[0145] As a possible implementation, the ratio of the position offset to the preset offset value may be used as the first weight, and the preset offset value and the position offset are subtracted, and the ratio of the difference to the preset offset value is used as the second weight.

[0146] For example, if the position offset is 100 meters and the preset offset value is 1000 meters, the first weight is 10% and the second weight is 90%.

[0147] As another possible implementation, multiple weight combinations may be preset, each weight combination including a first weight and a second weight, and each weight combination corresponds to a position offset interval, that is, the first weight and the second weight are determined according to the interval in which the position offset is located.

[0148] For example, five weight combinations are pre-set, namely (10%, 90%), (30%, 70%), (50%, 50%), (70%, 30%), and (90%, 10%). When the position offset is between 0 and 100 meters, the corresponding weight combination is (10%, 90%), when the position offset is between 100 and 300 meters, the corresponding weight combination is (30%, 70%), when the position offset is between 300 and 600 meters, the corresponding weight combination is (50%, 50%), when the position offset is between 600 and 900 meters, the corresponding weight combination is (70%, 30%), and when the position offset is between 900 and 1000 meters, the corresponding weight combination is (90%, 10%).

[0149] Assuming that the position offset is 750 meters, which is located between 600 and 900 meters, the corresponding weight combination is (70%, 30%), therefore, the first weight is 70% and the second weight is 30%.

[0150] S106-4, based on the first weight and the second weight, perform weighted summation on the satellite positioning information and the dead reckoning data at the receiving time to obtain a second starting position.

[0151] The product of the first longitude and the first weight, the product of the second longitude and the second weight are calculated, and then the two are summed to obtain the longitude of the second starting position.

[0152] Similarly, the product of the first latitude and the first weight, the product of the second latitude and the second weight are obtained, and then the two are summed to obtain the latitude of the second starting position.

[0153] It should be noted that in order to move the car's mark on the map on the display interface of the vehicle navigation system from the trajectory point corresponding to the dead reckoning data at the time of reception to the trajectory point corresponding to the second starting position, it is necessary to quickly converge the longitude and latitude coordinates of several trajectory points between the two trajectory points based on the vehicle's heading, filtering parameters and zero offset correction values, and move the car's mark on the map according to the longitude and latitude coordinates of the trajectory points during the convergence process.

[0154] It can be understood that the position offset is proportional to the time taken for the above-mentioned convergence process.

[0155] As a possible implementation manner, when the position offset is infinitely close to the preset offset value, the upper limit of the time used for the above convergence process can be set to 5 seconds.

[0156] S107, calculating fused positioning data of the vehicle at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the vehicle acquired at each driving moment.

[0157] like Fig. 9As shown, step S107 includes sub-steps S107-1 to S107-2.

[0158] S107-1, using the second starting position as the fused positioning data at the moment when the vehicle first receives the satellite positioning information.

[0159] It can be understood that when the car starts to receive the satellite positioning information, the second starting position determined based on the satellite positioning information and the dead reckoning data at the receiving time can be used as the fused positioning data of the car at this time.

[0160] S107-2, for each driving moment after the moment when the satellite positioning information is first received, determine the fused positioning data of the car at the driving moment based on the satellite positioning information at the driving moment, the inertial navigation data of the car at the driving moment, and the fused positioning data of the car at the previous moment of the driving moment.

[0161] Optionally, the implementation process of step S107-2 may be as follows:

[0162] First, the inertial navigation data of the car at the time of driving and the fused positioning data of the car at the previous time of driving are integrated to obtain the calculation result;

[0163] Then, based on the preset weights, the calculation results and the satellite positioning information received at the time of driving are weighted and summed to obtain the fused positioning data of the car at the time of driving.

[0164] The preset weight includes the weight of the calculation result and the weight of the satellite positioning information. The weight of the calculation result is less than the weight of the satellite positioning information. The preset weight can be set by setting a test experiment of the vehicle navigation system.

[0165] In the embodiment of the present invention, Fig.10 As shown, at driving time 6 the car can receive satellite positioning information P6, and at this time the second starting position (ie, fused positioning data K6 at driving time 6) is determined according to the satellite positioning information P6 and the dead reckoning data S6 at driving time 6.

[0166] For each driving moment after driving moment 6, the inertial navigation data of the vehicle at the driving moment and the fused positioning data at the previous driving moment are used for integration operation, and the obtained operation result is weighted summed with the satellite positioning information at the moment, and the final result is used as the fused positioning data of the vehicle at the driving moment. For example, the fused positioning data K10 of the vehicle at driving moment 10 is obtained by weighted summing the integration result of the fused positioning data K9 at driving moment 9 and the inertial navigation data a10 of the vehicle at driving moment 10, and the satellite positioning information P10 at driving moment 10.

[0167] S108, navigating the car according to the fused positioning data of the car at each driving moment.

[0168] During the driving process after the car is started, whether the car is navigated based on dead reckoning data or fused positioning data, the value of the positioning counter needs to be updated. The value of the positioning counter is used to determine whether the positioning data when the car enters the off state meets the preset conditions, and when the positioning data meets the preset conditions, the positioning data is used as the off position.

[0169] In this regard, Figure 7 Based on Fig.11 The car navigation method provided by the embodiment of the present invention further includes steps S109 to S112, and the process of steps S109 to S112 is executed in parallel with the process of steps S103 to S108.

[0170] S109, during the driving process of the car, obtaining the type of positioning data of the car at preset time intervals.

[0171] Among them, the types of positioning data include dead reckoning data and fused positioning data.

[0172] S110 , for the type of positioning data acquired each time, if the type of positioning data is fused positioning data, the value of the positioning counter is accumulated.

[0173] The fused positioning data is determined based on the satellite positioning information and has a high reliability. When the type of positioning data acquired is fused positioning data, the value of the positioning counter is directly accumulated (for example, accumulated by 1).

[0174] S111 , for the type of positioning data obtained each time, if the type of the positioning data is dead reckoning data and the positioning data converges, then the value of the positioning counter is accumulated.

[0175] S112: For the type of positioning data acquired each time, if the type of positioning data is dead reckoning data and the positioning data is not converged, the value of the positioning counter is not accumulated.

[0176] The dead reckoning data is obtained by integrating the inertial navigation data of the vehicle and the first starting position, and the integration process may not converge.

[0177] When the type of the acquired positioning data is dead reckoning data, if it converges, the value of the positioning counter is accumulated (for example, accumulated by 1); if it does not converge, the value of the positioning counter is not accumulated.

[0178] It should be noted that the situation where the dead reckoning data does not converge generally only exists when the in-vehicle navigation system is installed on the car for the first time.

[0179] The embodiment of the present invention also provides a method for determining an ignition off position, the execution subject of which is Figure 1 The main control chip in.

[0180] Please refer to Fig.12 The method for determining the flameout position includes steps S201 to S204.

[0181] S201, obtaining positioning data when the vehicle enters the ignition-off state, and determining whether the positioning data meets a preset condition.

[0182] The ignition-off position is used by the main control chip to determine the first starting position when executing the aforementioned car navigation method.

[0183] Optionally, the implementation process of “determining whether the positioning data meets the preset conditions” may be as follows:

[0184] Obtaining the value of the positioning counter when the vehicle is in an ignition-off state;

[0185] If the value of the positioning counter is greater than a preset threshold, it is determined that the positioning data meets the preset condition;

[0186] If the value of the positioning counter is not greater than the preset threshold, it is determined that the positioning data does not meet the preset condition.

[0187] When the value of the positioning counter is not greater than the preset threshold, it means that the car has been running for a short time after starting and then enters the off state, and the confidence of the positioning data when the car enters the off state is low. The preset threshold can be set by setting a test experiment of the vehicle navigation system.

[0188] S202: If the positioning data meets a preset condition, the positioning data is used as the flameout position.

[0189] S203: If the positioning data does not meet the preset conditions, the flameout position is calculated based on the positioning data at multiple moments before the vehicle enters the flameout state.

[0190] As a possible implementation method, the positioning data at a moment before the vehicle enters the flameout state and the inertial navigation data when the vehicle is flameout can be used to perform an integral operation, and the operation result is used as the flameout position.

[0191] S204: Generate a data frame recording the ignition-off position, and store the data frame.

[0192] Optionally, when generating a data frame recording the flameout position, a check field is inserted at a specific position in the data frame. After subsequently reading the data frame, the check field is checked to determine whether the flameout position recorded in the data frame is consistent with that before being written to the external memory.

[0193] Compared with the prior art, the technical effects of the embodiments of the present invention include:

[0194] (1) When the car is turned off, the car's ignition-off position is determined by judging whether the positioning data at that moment meets a preset condition, so that when the car is restarted, the car can be navigated based on the first starting position determined by the ignition-off position in the absence of satellite positioning information.

[0195] (2) During the process of navigating the vehicle, if satellite positioning information is received, a second starting position is determined according to a position offset between the satellite positioning information and the navigation data at the time of receiving the satellite positioning information, so as to navigate the vehicle based on the second starting position.

[0196] In order to execute the corresponding steps in the above method embodiment and each possible implementation mode, an implementation mode of the automobile navigation device 200 and an implementation mode of the ignition-off position determination device 300 are respectively provided below.

[0197] Please refer to Fig.13 The car navigation device 200 includes a first processing module 201 , a navigation module 202 and an updating module 203 .

[0198] The first processing module 201 is used to obtain a data frame recording the engine-off position of the vehicle if no satellite positioning information is received when the vehicle is started; wherein the engine-off position is the positioning data when the vehicle enters the engine-off state that meets the preset conditions or is calculated based on the positioning data at multiple moments before the vehicle enters the engine-off state.

[0199] The inertial navigation module 202 is used to use the ignition-off position recorded in the data frame as the first starting position if the data frame meets a preset verification condition, so as to navigate the vehicle based on the first starting position.

[0200] Optionally, the vehicle navigation system further includes an inertial element, the main control chip is electrically connected to the inertial element, and the first processing module 201 is further used to obtain inertial navigation data of the vehicle from the inertial element at each driving moment after the vehicle is started; calculate the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment; the navigation module 202 is further used to navigate the vehicle according to the dead reckoning data of the vehicle at each driving moment.

[0201] Optionally, when the first processing module 201 is used to calculate the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment, it is specifically used to use the first starting position as the dead reckoning data of the vehicle at the start-up moment; for each driving moment after the start-up moment, determine the dead reckoning data of the vehicle at the driving moment according to the inertial navigation data of the vehicle at the driving moment and the dead reckoning data of the vehicle at a moment before the driving moment.

[0202] Optionally, the first processing module 201 is also used to determine the second starting position according to the satellite positioning information and the dead reckoning data of the car at the time of receiving the satellite positioning information if satellite positioning information is received during the process of navigating the car; calculate the fused positioning data of the car at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the car acquired at each driving moment; the navigation module 202 is used to perform satellite navigation on the car according to the fused positioning data of the car at each driving moment.

[0203] Optionally, when the first processing module 201 is used to determine the second starting position according to the satellite positioning information and the dead reckoning data of the vehicle at the time of receiving the satellite positioning information, the first processing module 201 is specifically used to calculate the position offset between the satellite positioning information and the dead reckoning data at the time of receiving; if the position offset is greater than a preset offset value, the satellite positioning information is used as the satellite navigation starting position; if the position offset is not greater than the preset offset value, a first weight of the satellite positioning information and a second weight of the dead reckoning data at the time of receiving are determined according to the size of the position offset; based on the first weight and the second weight, a weighted sum is performed on the satellite positioning information and the dead reckoning data at the time of receiving to obtain the second starting position.

[0204] Optionally, the satellite positioning information includes a first longitude and a first latitude, and the dead reckoning data includes a second longitude and a second latitude; when the first processing module 201 is used to calculate the position offset between the satellite positioning information and the dead reckoning data at the reception time, it is specifically used to calculate a first difference between the first longitude and the second longitude, and a second difference between the first latitude and the second latitude, respectively; and take the maximum value of the absolute value of the first difference and the absolute value of the second difference as the position offset.

[0205] Optionally, when the first processing module 201 is used to calculate the fused positioning data of the car at each driving moment based on the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the car acquired at each driving moment, the first processing module 201 is specifically used to use the second starting position as the fused positioning data of the car at the moment when the satellite positioning information is first received; for each driving moment after the moment when the satellite positioning information is first received, the fused positioning data of the car at the driving moment is determined based on the satellite positioning information at the driving moment, the inertial navigation data of the car at the driving moment, and the fused positioning data of the car at the moment before the driving moment.

[0206] Optionally, when the first processing module 201 is used to determine the fused positioning data of the car at the time of driving based on the satellite positioning information at the time of driving, the inertial navigation data of the car at the time of driving, and the fused positioning data of the car at the previous moment of driving, the first processing module 201 is specifically used to perform an integral operation on the inertial navigation data of the car at the time of driving and the fused positioning data of the car at the previous moment of driving to obtain a calculation result; based on a preset weight, a weighted sum is performed on the calculation result and the satellite positioning information received at the time of driving to obtain the fused positioning data of the car at the time of driving.

[0207] Optionally, the updating module 203 is used to obtain the type of positioning data of the automobile at preset time intervals during the driving process of the automobile; for the type of positioning data obtained each time, if the type of positioning data is fused positioning data, the value of the positioning counter is accumulated; if the type of positioning data is dead reckoning data and the positioning data converges, the value of the positioning counter is accumulated; if the type of positioning data is fused positioning data and the positioning data does not converge, the value of the positioning counter is not accumulated, wherein the value of the positioning counter is used to determine whether the positioning data when the automobile enters the ignition-off state meets a preset condition, and when the positioning data meets the preset condition, the positioning data is determined as the ignition-off position.

[0208] Optionally, the first processing module 201 is used to determine whether the data frame meets the preset verification conditions before using the ignition off position recorded in the data frame as the first starting position if the data frame meets the preset verification conditions, specifically to intercept a preset field in the data frame; if the value of the preset field is a preset verification value, it is determined that the data frame meets the preset verification conditions.

[0209] Please refer to Fig.14 The device 300 for determining the flameout position includes an acquisition module 301 and a second processing module 302 .

[0210] The acquisition module 301 is used to acquire the positioning data when the vehicle enters the ignition-off state;

[0211] The second processing module 302 is used to determine whether the positioning data meets the preset conditions; if the positioning data meets the preset conditions, the positioning data is used as the flameout position; if the positioning data does not meet the preset conditions, the flameout position is calculated based on the positioning data of multiple moments before the car enters the flameout state; wherein the flameout position is used to determine the first starting position when the main control chip executes the aforementioned car navigation method; a data frame recording the flameout position is generated, and the data frame is stored.

[0212] Optionally, the vehicle navigation system also includes a positioning counter electrically connected to the main control chip. When the second processing module 302 is used to determine whether the positioning data meets the preset conditions, it is specifically used to obtain the value of the positioning counter when the car is in the ignition off state; if the value of the positioning counter is greater than a preset threshold, it is determined that the positioning data meets the preset conditions; if the value of the positioning counter is not greater than the preset threshold, it is determined that the positioning data does not meet the preset conditions.

[0213] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described automobile navigation device 200 and the ignition-off position determination device 300 can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0214] An embodiment of the present invention further provides a computer-readable storage medium containing a computer program. When the computer program is executed, it can be used to perform the car navigation method provided by the above method embodiment and / or the related operations in the method for determining the ignition off position.

[0215] In summary, the embodiments of the present invention provide a method for navigating a car, a method for determining a flameout position, and related devices. First, if satellite positioning information is not received when the car is started, a data frame recording the flameout position of the car is obtained, wherein the flameout position is the positioning data when the car enters the flameout state that meets the preset conditions or is calculated based on the positioning data at multiple moments before the car enters the flameout state; then, if the data frame meets the preset verification conditions, the flameout position recorded in the data frame is used as the first starting position to navigate the car based on the first starting position. Since the embodiments of the present invention can accurately determine the flameout position of the car when the car is in the flameout state, when the car is started again, the car can be navigated based on the first starting position determined by the flameout position in the absence of satellite positioning information.

[0216] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A car navigation method, characterized in that: A main control chip applied to a vehicle navigation system, the method comprising: If no satellite positioning information is received when the car is started, a data frame recording the shutdown position of the car is obtained; The flameout position is the positioning data of the vehicle when it enters the flameout state that meets the preset conditions or is calculated based on the positioning data of multiple moments before the vehicle enters the flameout state; If the data frame satisfies a preset verification condition, the ignition-off position recorded in the data frame is used as a first starting position, so as to navigate the vehicle based on the first starting position; The vehicle navigation system further includes an inertial element, the main control chip is electrically connected to the inertial element, and at each driving moment after the vehicle is started, the inertial navigation data of the vehicle is obtained from the inertial element; Calculating the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment; Navigating the vehicle according to the dead reckoning data of the vehicle at each driving moment; During navigation of the vehicle, if the satellite positioning information is received, determining a second starting position according to the satellite positioning information and dead reckoning data of the vehicle at the time of receiving the satellite positioning information; Calculate the fused positioning data of the vehicle at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the vehicle acquired at each driving moment; Navigating the vehicle according to the fused positioning data of the vehicle at each driving moment; The step of determining a second starting position according to the satellite positioning information and the dead reckoning data of the vehicle at the time of receiving the satellite positioning information comprises: Calculating a position offset between the satellite positioning information and the dead reckoning data at the receiving time; If the position offset is greater than a preset offset value, using the satellite positioning information as the second starting position; If the position offset is not greater than a preset offset value, determining a first weight of the satellite positioning information and a second weight of the dead reckoning data at the receiving time according to the size of the position offset; Based on the first weight and the second weight, a weighted sum is performed on the satellite positioning information and the dead reckoning data at the receiving time to obtain the second starting position.

2. The method according to claim 1, characterized in that The step of calculating the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment comprises: Using the first starting position as dead reckoning data of the vehicle at the start time; For each of the driving moments after the start moment, the dead reckoning data of the vehicle at the driving moment is determined according to the inertial navigation data of the vehicle at the driving moment and the dead reckoning data of the vehicle at a moment before the driving moment.

3. The method according to claim 1, characterized in that The satellite positioning information includes a first longitude and a first latitude, and the dead reckoning data includes a second longitude and a second latitude; The step of calculating the position offset between the satellite positioning information and the dead reckoning data at the receiving time comprises: respectively calculating a first difference between the first longitude and the second longitude, and a second difference between the first latitude and the second latitude; The maximum value of the absolute value of the first difference and the absolute value of the second difference is used as the position offset.

4. The method according to claim 1, characterized in that The step of calculating the fused positioning data of the vehicle at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the vehicle acquired at each driving moment comprises: Using the second starting position as fused positioning data at the moment when the vehicle first receives the satellite positioning information; For each driving moment after the moment when the satellite positioning information is first received, the fused positioning data of the car at the driving moment is determined based on the satellite positioning information at the driving moment, the inertial navigation data of the car at the driving moment, and the fused positioning data of the car at the moment before the driving moment.

5. The method according to claim 4, characterized in that The step of determining the fused positioning data of the vehicle at the driving time according to the satellite positioning information at the driving time, the inertial navigation data of the vehicle at the driving time, and the fused positioning data of the vehicle at a moment before the driving time comprises: Performing an integral operation on the inertial navigation data of the vehicle at the driving moment and the fused positioning data of the vehicle at a moment before the driving moment to obtain a calculation result; Based on preset weights, a weighted sum is performed on the calculation result and the satellite positioning information received at the driving time to obtain fused positioning data of the car at the driving time.

6. The method according to any one of claims 1 to 5, characterized in that The vehicle navigation system further includes a positioning counter electrically connected to the main control chip, and the method further includes: During the driving of the vehicle, the type of positioning data of the vehicle is obtained at preset time intervals; For the type of the positioning data obtained each time, if the type of the positioning data is fused positioning data, accumulating the value of the positioning counter; If the type of the positioning data is dead reckoning data and the positioning data converges, accumulating the value of the positioning counter; If the type of the positioning data is dead reckoning data and the positioning data does not converge, the value of the positioning counter is not accumulated; The value of the positioning counter is used to determine whether the positioning data when the vehicle enters the ignition-off state meets a preset condition, and when the positioning data meets the preset condition, the positioning data is determined as the ignition-off position.

7. The method according to claim 1, characterized in that Before the step of using the ignition-off position recorded in the data frame as the inertial navigation starting position if the data frame meets the preset verification condition, the method further includes the step of determining whether the data frame meets the preset verification condition, which includes: intercepting a preset field in the data frame; If the value of the preset field is a preset check value, it is determined that the data frame meets the preset check condition.

8. A method for determining an ignition off position, characterized in that: A main control chip applied to a vehicle navigation system, the method comprising: Acquire the positioning data of the vehicle when it enters the engine-off state, and determine whether the positioning data meets a preset condition; If the positioning data meets the preset condition, the positioning data is used as the flameout position; If the positioning data does not meet the preset conditions, the flameout position is calculated based on the positioning data at multiple moments before the vehicle enters the flameout state; Wherein, the ignition-off position is used for determining a first starting position when the main control chip executes the automobile navigation method according to any one of claims 1 to 7; A data frame recording the ignition-off position is generated and the data frame is stored.

9. The method according to claim 8, characterized in that The vehicle navigation system further includes a positioning counter electrically connected to the main control chip, and the step of determining whether the positioning data meets a preset condition includes: Obtaining the value of the positioning counter when the vehicle is in an ignition-off state; If the value of the positioning counter is greater than a preset threshold, it is determined that the positioning data meets a preset condition; If the value of the positioning counter is not greater than a preset threshold, it is determined that the positioning data does not meet a preset condition.

10. A car navigation device, characterized in that: A main control chip used in a vehicle navigation system, the device comprising: The first processing module is used for: If no satellite positioning information is received when the car is started, a data frame recording the shutdown position of the car is obtained; The flameout position is the positioning data of the vehicle when it enters the flameout state that meets the preset conditions or is calculated based on the positioning data of multiple moments before the vehicle enters the flameout state; Navigation module for: If the data frame satisfies a preset verification condition, the ignition-off position recorded in the data frame is used as a first starting position, so as to navigate the vehicle based on the first starting position; The vehicle navigation system further includes an inertial element, the main control chip is electrically connected to the inertial element, and the first processing module is further used to obtain the inertial navigation data of the vehicle from the inertial element at each driving moment after the vehicle is started; calculate the dead reckoning data of the vehicle at each driving moment according to the first starting position and the inertial navigation data of the vehicle at each driving moment; navigate the vehicle according to the dead reckoning data of the vehicle at each driving moment; in the process of navigating the vehicle, if the satellite positioning information is received, determine the second starting position according to the satellite positioning information and the dead reckoning data of the vehicle at the time of receiving the satellite positioning information; calculate the fused positioning data of the vehicle at each driving moment according to the second starting position, the satellite positioning information received at each driving moment, and the inertial navigation data of the vehicle obtained at each driving moment; navigate the vehicle according to the fused positioning data of the vehicle at each driving moment; When the first processing module is used to determine the second starting position according to the satellite positioning information and the dead reckoning data of the automobile at the time of receiving the satellite positioning information, the first processing module is specifically used to calculate the position offset between the satellite positioning information and the dead reckoning data at the time of receiving; if the position offset is greater than a preset offset value, the satellite positioning information is used as the second starting position; if the position offset is not greater than the preset offset value, a first weight of the satellite positioning information and a second weight of the dead reckoning data at the time of receiving are determined according to the size of the position offset; and based on the first weight and the second weight, a weighted sum is performed on the satellite positioning information and the dead reckoning data at the time of receiving to obtain the second starting position.

11. A flameout position determination device, characterized in that: A main control chip used in a vehicle navigation system, the device comprising: Get modules for: Acquiring positioning data when the vehicle enters an engine-off state; The second processing module is used for: Determining whether the positioning data meets a preset condition; If the positioning data meets the preset condition, the positioning data is used as the flameout position; If the positioning data does not meet the preset conditions, the flameout position is calculated based on the positioning data at multiple moments before the vehicle enters the flameout state; Wherein, the ignition-off position is used for determining a first starting position when the main control chip executes the automobile navigation method according to any one of claims 1 to 7; A data frame recording the ignition-off position is generated and the data frame is stored.

12. A main control chip, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method for automobile navigation according to any one of claims 1 to 7 and / or the method for determining an ignition-off position according to any one of claims 8 to 9 is implemented.

13. A vehicle navigation system, characterized in that: Comprising the main control chip as claimed in claim 12.

14. A computer-readable storage medium, characterized in that: It stores a computer program, and when the computer program is processed and executed, it implements the car navigation method according to any one of claims 1 to 7, and / or the method for determining the shutdown position according to any one of claims 8 to 9.

Images