Self position estimation device

Abstract

A self-position estimation device is provided with: a vehicle position information acquisition unit; the first memory is used for storing the encrypted map information; a microcomputer that reads the map information, performs calculation on the basis of the information obtained from the position information acquisition unit, and outputs driving assistance information; and a second memory that holds the map information and current position information transmitted by the microcomputer, the position information acquisition unit, the first memory, and the second memory are connected to the microcomputer via a communication line, the second memory is a non-volatile memory of the vehicle, and during operation of the vehicle, the current position information is stored in the first memory. And storing the own position information, the encrypted peripheral map information and the decrypted peripheral map information.

Description

Technical Field

[0001] The present invention relates to a self-position estimating device and a driving assistance device, and for example, to a self-position estimating device for driving assistance that develops map data in a nonvolatile memory and a driving assistance device having a self-position estimating function. Background Art

[0002] In recent years, a number of non-volatile memories characterized by a high number of rewrite times have been realized, and several of them have been commercialized. Typical examples include magnetoresistive RAM (MRAM), ferroelectric RAM (FeRAM), resistance change RAM (ReRAM), phase change RAM (PRAM), and carbon nanotube RAM (NRAM). Since they have a large number of rewrite times and non-volatility, they are expected to be used in various applications.

[0003] As a device using such a nonvolatile memory, there is a device described in Patent Document 1. In this publication, a control method for extracting access performance when FeRAM or the like is used as RAM is described. In addition, Patent Document 2 describes the case of using FeRAM as a storage area for writing programs. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-21450 Patent Document 2: Japanese Patent Application Publication No. 2019-185398 Summary of the invention Problem that the invention aims to solve

[0005] Among the driving assistance functions of automobiles, the need for the self-position estimation function has increased in recent years. This is because, in order to support the European ISA (Intelligent Speed ​​Assistance) obligations, driving assistance based on the self-position and the corresponding map data is required.

[0006] However, there are various problems in the existing self-position estimation devices, among which there are two particularly serious problems. One is the length of time from startup to the time when the self-position information can be used for driving assistance. This is because it takes time for GNSS to calculate the position information, and it is necessary to obtain and expand the surrounding map information after the estimation of the self-position information is completed. Therefore, driving assistance based on the self-position information cannot be implemented within a certain period of time after the ignition is turned on.

[0007] Another reason is that a large memory is required to process large amounts of map data. Therefore, in a cheap microcomputer that does not have a DRAM I / F, the RAM capacity is small and map data cannot be processed, so an expensive SoC is required. The latter is particularly the reason why the position estimation device becomes expensive, which is one of the main reasons that hinder the popularization of higher-function driving assistance. Technical means of solving problems

[0008] An example of the self-position estimating device of the present invention includes: A vehicle position information acquisition unit; A first memory storing encrypted map information; a microcomputer that reads the map information, performs calculations based on the information obtained from the position information acquisition unit, and outputs driving assistance information; and a second memory for storing the map information and current position information transmitted by the microcomputer, The position information acquisition unit, the first memory, and the second memory are connected to the microcomputer via a communication line. The second memory is a non-volatile memory of the vehicle, and stores the vehicle's own position information, encrypted surrounding map information, and decrypted surrounding map information during the operation of the vehicle.

[0009] An example of a driving assistance device according to the present invention includes the self-position estimating device described above, Driving assistance devices include: Self-location estimation function; and A driving assistance function is executed using the own position estimated by the own position estimating function. Effects of the Invention

[0010] By using the self-position estimating device of one example of the present invention, map data can be processed in a system using an inexpensive microcomputer that does not have a DRAM I / F, so the price of the self-position estimating device can be reduced.

[0011] Furthermore, by using the self-position estimation device of one example of the present invention, it is possible to obtain surrounding map information from the outside through the Internet and perform calculations in a system using an inexpensive microcomputer without DRAM I / F, thereby achieving a low price for the self-position estimation device.

[0012] Furthermore, by using the own position estimating device of one example of the present invention, it is possible to avoid the danger of extracting map information from the own position estimating device after driving.

[0013] Furthermore, by using the self-position estimating device of one example of the present invention, driving assistance based on self-position estimation can be started immediately after startup, and the effect of achieving driving assistance from the start of driving can be obtained.

[0014] In addition, as in the driving assistance device of one example of the present invention, a device that provides a self-position estimation function and a device that performs driving assistance using information provided by the self-position estimation device may be integrated. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the structure of the self-position estimating device of Example 1. Figure 2 This is the memory structure and data operation of the self-position estimating device of the first embodiment. Figure 3 This is a flowchart showing the operation flow of the self-position estimating device of the first embodiment. Figure 4 This is the structure of the self-position estimating device of Example 2. Figure 5 This is a flowchart showing the operation flow of the self-position estimating device of the third embodiment. Figure 6 This is a flowchart showing the operation flow of the self-position estimating device of the fourth embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, Embodiments 1 to 4 related to the self-position estimating device and Embodiment 5 related to the driving assistance device will be described with reference to the drawings.

[0017] [Example 1] Figure 1 The structure of the self-position estimation device of the first embodiment of the present invention is shown. The self-position estimation device 101 has a microcomputer 102, a vehicle position information acquisition unit 103, a non-volatile memory 104 (second memory), and a large-capacity memory 105 (first memory) inside. The microcomputer 102 has a processor. The position information acquisition unit 103 has a sensor group related to position information acquisition, such as a GNSS information acquisition unit 106 (GNSS: Global Navigation Satellite System) and an IMU sensor 107 (IMU: Inertial Measurement Unit). The GNSS information acquisition unit 106 can acquire information provided by satellite navigation.

[0018] The position information acquisition unit 103 (more specifically, the GNSS information acquisition unit 106 and the IMU sensor 107 ), the nonvolatile memory 104 , and the large-capacity memory 105 are connected to the microcomputer 102 via communication lines, respectively.

[0019] The large capacity memory 105 stores encrypted map information. For example, the large capacity memory 105 stores wide area encrypted map information 110. The nonvolatile memory 104 stores surrounding map information. The surrounding map information includes encrypted surrounding map information 109 obtained by copying necessary parts of the encrypted map information 110, and decrypted surrounding map information 108 generated by decrypting the encrypted map information 110.

[0020] In addition, the nonvolatile memory 104 may be MRAM, FeRAM, ReRAM, PRAM or NRAM. When using these memories, it is preferable from the aspect of very large number of rewrites. The large capacity memory 105 is a nonvolatile memory characterized by low price and large capacity such as NAND Flash, but it is not limited to the described memory as long as it has this feature.

[0021] In addition, although the GNSS information acquisition unit 106 and the IMU sensor 107 are described as examples of the position information acquisition unit 103, these are representative examples of sensors that can be used for position information acquisition, and the types of sensors are not limited thereto. For example, a sensor using a camera may also be used.

[0022] In addition, regarding the encrypted map information 110 and the encrypted surrounding map information 109, "encryption" does not limit the encryption method. In addition, it is not necessary to perform encryption, but it may include obfuscation. For example, even if it does not meet the specific definition of the term "encryption", it is sufficient as long as it is difficult to read compared to the map information before processing. As a specific example, it includes a state in which it can be read through a specified operation even if the key for decryption is unknown.

[0023] Figure 2 The following shows the memory structure and data operation of the self-position estimating device 101 according to this embodiment. Figure 2 In particular, the description focuses on the operation of the data of the own position estimation device 101.

[0024] The own position estimation device 101 of this embodiment first copies the encrypted map information of a predetermined range around the own position from the encrypted map information 110 stored in the large-capacity memory 105 to the non-volatile memory 104 as the encrypted surrounding map information 109 based on the own position estimation information (for example, information indicating the estimated own position of the vehicle). At this time, since the data is transmitted successively, there is no problem even if the RAM size of the microcomputer 102 itself is smaller than the data size of the encrypted surrounding map information 109.

[0025] Next, the microcomputer 102 sequentially reads the data included in the encrypted surrounding map information 109 and writes it into the nonvolatile memory 104 as the decrypted surrounding map information 108. At this time, since the data is also sequentially transmitted and processed, there is no problem even if the size of the RAM of the microcomputer 102 itself is smaller than the data size of the encrypted surrounding map information 109 and the decrypted surrounding map information 108.

[0026] The nonvolatile memory 104 stores self-position estimation information 205 (self-position information) indicating the estimated self-position of the vehicle, and the microcomputer 102 can read and write the self-position estimation information 205. The self-position estimation information 205 can be obtained from the position information acquisition unit 103, for example.

[0027] In this way, the nonvolatile memory 104 holds the map information (eg, the encrypted surrounding map information 109 and the decrypted surrounding map information 108) and the current position information (eg, the own position estimated information 205) transmitted from the microcomputer 102.

[0028] Figure 3 1 is a flowchart showing the action flow of the self-position estimation device 101 of this embodiment, and in particular, a diagram showing the action in action (normal action). During driving, the self-position estimation device 101 updates the self-position estimation information 205 based on the information regularly acquired from the position information acquisition unit 103 (S100). Then, based on the self-position estimation information 205, it is determined whether it is necessary to read the next surrounding map information (S110). For example, it is determined whether all the map information within a specified range based on the self-position has been read out. If there is an unread part, it is determined that the next surrounding map information needs to be read out. In the case where the next surrounding map information needs to be read out, the unused surrounding map information is deleted from the non-volatile memory (S120). At this time, the corresponding parts of both the encrypted surrounding map information 109 and the decrypted surrounding map information 108 are deleted.

[0029] After the nonvolatile memory 104 has a vacant space due to deletion, the encrypted surrounding map information 109 is read out according to the range of the surrounding map required and copied to the nonvolatile memory 104 (S130). Then, the microcomputer 102 decrypts the newly expanded encrypted surrounding map information 109 in the nonvolatile memory 104 while reading it out, and writes the decrypted surrounding map information 108 into the nonvolatile memory (S140).

[0030] In this way, the nonvolatile memory 104 stores: the vehicle's own position information (such as the estimated own position information 205), the encrypted surrounding map information (such as the encrypted surrounding map information 109), and the decrypted surrounding map information (such as the decrypted surrounding map information 108) during the vehicle's operation.

[0031] After the decryption of the decrypted surrounding map information 108 is completed, the information required for driving assistance is provided to the driving assistance device (S150) based on the self-position estimation information 205 and the information included in the decrypted surrounding map information 108. In this way, the microcomputer 102 reads the map information, performs calculations based on the information obtained from the position information acquisition unit 103, and outputs the driving assistance information. The driving assistance information includes, for example, information related to the speed limit, information related to the sharp turn, information related to the slope of the road, etc.

[0032] If it is determined in S110 that the next surrounding map does not need to be read, the information required for driving assistance is provided to the driving assistance device based on the self-position estimation information 205 and the decrypted surrounding map information 108 currently stored in the nonvolatile memory 104 (S150).

[0033] As described above, according to the self-position estimation device 101 of this embodiment, even when using an inexpensive microcomputer 102 with a relatively small RAM size without a DRAM I / F, practical map data can be processed, thereby achieving a low price of the self-position estimation device 101.

[0034] [Example 2] Figure 4 The configuration of the self-position estimating device according to the second embodiment of the present invention is shown. Hereinafter, description of the same parts as those of the first embodiment may be omitted.

[0035] The own position estimation device 401 has therein a microcomputer 102 , a vehicle position information acquisition unit 103 , a nonvolatile memory 104 (memory), and a communication IC 405 (network interface).

[0036] The position information acquisition unit 103 (more specifically, the GNSS information acquisition unit 106 and the IMU sensor 107 ), the communication IC 405 , and the nonvolatile memory 104 are connected to the microcomputer 102 via a communication line.

[0037] Communication IC 405 is connected to map server 411 located in data center 410 via a network. In response to a request indicating a specific area from communication IC 405, map server 411 obtains map information of the corresponding area from wide-area encrypted map information 412 and sends it to communication IC. Communication IC 405 receives the map information and transmits it to microcomputer 102.

[0038] The surrounding map information is stored in the nonvolatile memory 104. The surrounding map information includes the received encrypted surrounding map information 109 and the decrypted surrounding map information 108 generated by decrypting the received encrypted surrounding map information 109.

[0039] In this way, the nonvolatile memory 104 holds the encrypted map information (eg, the encrypted surrounding map information 109 ) and the current position information (eg, the own position estimation information) acquired and transmitted by the microcomputer 102 via the network.

[0040] In addition, the nonvolatile memory 104 is not limited to the described memory as long as it has the same features as the nonvolatile memory 104 of Example 1. In addition, the communication IC 405 can be connected to an external network such as Ethernet (registered trademark) and is an IC corresponding to a communication method that can process large-capacity data such as map data, but the communication method is not limited.

[0041] In addition, regarding the position information acquisition unit 103, similarly to the position information acquisition unit 103 of the first embodiment, the type of sensor is not limited.

[0042] Furthermore, regarding the encrypted map information 412 and the encrypted surrounding map information 109, the encryption method is not limited, and they may be obfuscated instead of encrypted.

[0043] The operation of the self-position estimation device 401 of the second embodiment is based on the operation of the self-position estimation device 101 of the first embodiment, except that the storage location of the encrypted map is located inside or outside the self-position estimation device. Figure 1 The portion of the large capacity memory 105 becomes the map server 411, but the flow of other data is the same. Figure 3 The action of is equal to that of the self-position estimating device (1) of Example 1.

[0044] In particular, the microcomputer 102 performs calculations based on the information obtained from the position information acquisition unit 103 and outputs driving assistance information. In addition, the non-volatile memory 104 stores the following during the operation of the vehicle: the vehicle's own position information (e.g., the estimated own position information 205), the encrypted surrounding map information (e.g., the encrypted surrounding map information 109), and the decrypted surrounding map information (e.g., the decrypted surrounding map information 108).

[0045] As described above, according to the self-position estimation device 401 of this embodiment, even when using an inexpensive microcomputer 102 without a DRAM I / F, it is possible to obtain surrounding map information from the outside via the Internet etc. for calculation. This makes it possible to reduce the price of the self-position estimation device.

[0046] [Example 3] The self-position estimating device of the third embodiment adds an operation at the end from the viewpoint of safety to the self-position estimating device of the first or second embodiment.

[0047] Figure 5 This is a flowchart showing the operation flow of the self-position estimating device of the third embodiment. Figure 5 This is a process indicating that the operation of the self-position estimating device has been completed.

[0048] When an operation stop request (also referred to as an end notification) is sent to the own position estimation device by turning off the ignition of the vehicle or the like (S200), the own position estimation device deletes the decrypted surrounding map information 108 stored in the non-volatile memory 104 (S210). Then, it is confirmed whether the deletion of the decrypted surrounding map information 108 has been completed (S220). If it has not been completed (S220: No), the deletion process of the undeleted decrypted surrounding map information 108 (the above-mentioned S210) is executed or continued. In this way, the microcomputer 102 discards the decrypted surrounding map information in response to the operation stop request. When the deletion of the decrypted surrounding map information 108 is confirmed (S220: Yes), the operation is stopped (S230).

[0049] This can prevent the decrypted surrounding map information 108 from being read from outside after the operation stops. That is, it is possible to avoid the danger of extracting map information from the own position estimation device after the vehicle is running.

[0050] Even if the own position estimation information 205 and the encrypted surrounding map information 109 are stored in the nonvolatile memory 104, the microcomputer 102 does not delete them. That is, the microcomputer 102 saves the own position estimation information 205 and the encrypted surrounding map information 109 when the operation is stopped.

[0051] [Example 4] The self-position estimation device of the fourth embodiment is different from the self-position estimation device of the third embodiment, and can advance the start time of driving assistance by using the encrypted surrounding map information and self-position estimation information stored in the non-volatile memory at startup.

[0052] Figure 6 The following is a flow of operations of the self-position estimating device of the fourth embodiment. Figure 6 The operation related to activation of the own position estimating device is shown.

[0053] When the own position estimation device is started up by turning on the ignition of the vehicle or the like (S300), the own position estimation device checks whether the own position estimation information 205 and the encrypted surrounding map information 109 are stored in the non-volatile memory 104 (S310). Thus, in response to the start of the vehicle, the microcomputer 102 refers to the own position estimation information 205 and the encrypted surrounding map information 109 stored in the non-volatile memory 104.

[0054] When the self-position estimation information 205 and the encrypted surrounding map information 109 are stored (S310: Yes), the encrypted surrounding map information 109 is decrypted (S320). Thus, when the self-position estimation information 205 and the encrypted surrounding map information 109 are stored in the non-volatile memory 104, the microcomputer 102 decrypts the encrypted surrounding map information 109 and stores it in the non-volatile memory 104.

[0055] After the decrypted surrounding map information 108 is output to the non-volatile memory, the self-position estimation information 205 and the decrypted surrounding map information 108 are read out, and the calculation of the information required for driving assistance is started based on these information (S321), and driving assistance is started (S322). In this way, the microcomputer 102 outputs driving assistance information using the self-position estimation information 205 and the decrypted surrounding map information 108.

[0056] Since the processing up to this point does not require GNSS, the following effect can be achieved: compared with a configuration in which the self-position is estimated based on information such as GNSS and the encrypted surrounding map information is read out after the self-position estimation is completed, driving assistance can be started at an earlier time. In other words, driving assistance based on the self-position estimation can be started shortly after the start, and the effect of driving assistance from the start of driving can be achieved.

[0057] In addition, in S320 to S322, if there is a usable sensor (IMU sensor 107 or other sensor), it can also be used. In addition, if GNSS becomes usable, if information from GNSS is used at this time, the own position can be estimated with higher accuracy.

[0058] When the encrypted surrounding map information 109 is not stored in the non-volatile memory 104 at the time of initial startup (S310: No), the location information is acquired in the same manner as in the existing own position estimation device (S330), and it is repeatedly confirmed whether the acquisition of the location information is completed (S340). If the acquisition of the location information is completed, the necessary encrypted surrounding map information is copied from the encrypted surrounding map information 109 to the non-volatile memory 104 in sequence (S350), the encrypted surrounding map information 109 is decrypted (S351), the own position estimation information 205 and the decrypted surrounding map information 108 are read out (S352), and the calculation of the information required for driving assistance is started based on this information, and driving assistance is started (S353).

[0059] In this case, although the effect of speeding up the time from startup to the start of driving assistance cannot be achieved, the self-position estimation information 205 and encrypted surrounding map information 109 (see Example 3) remain in the non-volatile memory when the normal action is completed, so the situation where the effect cannot be achieved is limited to a very small part.

[0060] [Example 5] The driving assistance device of this embodiment is a device configured to perform self-position estimation by any one of the self-position estimation devices of Embodiments 1 to 4 and output driving assistance information, and to perform driving assistance using the information. That is, the self-position estimation device 101 or 401 also functions as a driving assistance device. Hereinafter, the description of the same parts as any one of Embodiments 1 to 4 is sometimes omitted.

[0061] For example, the microcomputer 102 has a multi-core structure, that is, includes a plurality of processors. Furthermore, one or more of the plurality of processors realizes the self-position estimation device of any one of the first to fourth embodiments, and another one or more of the plurality of processors realizes the driving assistance device.

[0062] As described above, the driving assistance device of this embodiment includes a self-position estimating device and has a self-position estimating function, and also has a function of performing driving assistance using the self-position estimated by the self-position estimating function.

[0063] There is no particular limitation on the specific content of driving assistance, but those skilled in the art can make appropriate designs based on known technologies, for example, operations related to accelerator, brake, steering, etc. can be assisted.

[0064] As an effect of the self-position estimation device of Examples 1 to 4, since the function of the self-position estimation device can be realized by an inexpensive microcomputer, it can be integrated with a driving assistance device realized by an inexpensive microcomputer, and the effect of high-performance driving assistance based on self-position estimation can be obtained even with a low-priced driving assistance device. That is, the device on the side that provides the self-position estimation function and the device on the side that performs driving assistance using the information provided by the self-position estimation device can be integrated. Explanation of symbols

[0065] 101: Self-position estimation device (driving assistance device) 102: Microcomputer 103: Location information acquisition unit 104: non-volatile memory (second memory, memory) 105: Large capacity memory (first memory) 106: GNSS information acquisition department 107: IMU sensor 108: Decrypted surrounding map information (decrypted surrounding map information) 109: Encrypt surrounding map information (encrypted surrounding map information) 110: Encrypted map information 205: Estimated own position information (own position information) 401: Self-position estimation device (driving assistance device) 405: Communication IC (network interface).

Claims

1. A self-position estimating device, characterized in that: have: A vehicle position information acquisition unit; A first memory storing encrypted map information; a microcomputer that reads the map information, performs calculations based on the information obtained from the position information acquisition unit, and outputs driving assistance information; as well as a second memory for storing the map information and current position information transmitted by the microcomputer, The position information acquisition unit, the first memory, and the second memory are connected to the microcomputer via a communication line. The second memory is a non-volatile memory of the vehicle, and stores the vehicle's own position information, encrypted surrounding map information, and decrypted surrounding map information during the operation of the vehicle.

2. A self-position estimation device, characterized in that: have: A vehicle position information acquisition unit; a microcomputer that performs calculations based on the information obtained from the position information acquisition unit and outputs driving assistance information; as well as A memory that stores encrypted map information and current location information acquired and transmitted by the microcomputer through a network interface, The position information acquisition unit, the network interface, and the memory are connected to the microcomputer via a communication line. The memory is a non-volatile memory of the vehicle, and stores the vehicle's own position information, encrypted surrounding map information, and decrypted surrounding map information during the operation of the vehicle.

3. The self-position estimating device according to claim 1 or 2, characterized in that: The microcomputer discards the decrypted surrounding map information in response to the action stop request. The microcomputer saves its own position information and encrypted surrounding map information when the operation stops.

4. The self-position estimating device according to claim 1, characterized in that: In response to the vehicle being started, the microcomputer refers to the self-position information and the encrypted surrounding map information stored in the second memory, When the second memory has the own location information and the encrypted surrounding map information, the microcomputer decrypts the encrypted surrounding map information and stores it in the second memory. The microcomputer outputs driving assistance information using its own position information and the decrypted surrounding map information.

5. The self-position estimating device according to claim 1, characterized in that: The second memory is MRAM, FeRAM, ReRAM, PRAM or NRAM.

6. A driving assistance device, characterized in that: have: The self-position estimating device according to claim 1 or 2, The driving assistance device comprises: Self-location estimation function; and A driving assistance function is executed using the own position estimated by the own position estimating function.

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