Underwater positioning and wireless charging method based on megahertz communication

Abstract

An underwater positioning method and a wireless charging method based on megahertz communication comprise the following steps: step S01, starting to call a database; s02, collecting data at the position 1, and then advancing in any direction for random time; step S03, acquiring data at the position 2, and then advancing for random time in any direction; step S04, acquiring data at a position 3; step S05, comparing a database to determine whether a unique position is obtained, if so, entering the next step, and if not, returning to the step S02; and step S06, acquiring the exact position of the underwater robot, and establishing a shortest path for the charging pile. According to the invention, the megahertz wireless communication technology is applied to underwater wireless charging scenes such as swimming pools and the like to realize wireless communication of dozens of meters, and based on this, the positioning precision is improved, the wireless charging process is optimized, and the charging efficiency is improved.

Description

[0001] An underwater positioning and wireless charging method based on megahertz communication Technical Field

[0002] The invention belongs to the field of underwater positioning and relates to an underwater positioning and wireless charging method based on megahertz communication. Background Art

[0003] With the rise of equipment such as battery-powered underwater robots, applying wireless charging to such underwater equipment is becoming an industry trend.

[0004] Wireless charging is used underwater mainly due to its three advantages, namely safety, convenience and cost reduction. Safety comes from the inherent properties of wireless charging, that is, it can wirelessly transmit power in water (including fresh water and sea water) without the need for physical contact of metal plugs. Therefore, charging is very convenient; at the same time, it reduces the manual intervention of cable deployment and charging, and reduces a lot of manpower, material resources and time costs.

[0005] Whether in the air or in the water, wireless power transmission requires the establishment of wireless communication as a prerequisite. However, the performance of wireless communication in water is far inferior to that in air. For example, wireless communication technologies such as Bluetooth and Wi-Fi based on 2.4GHz can transmit more than 100 meters in the air, but at 1 meter underwater, the actual measurement is only 3 centimeters. This is mainly due to the strong attenuation effect of underwater media on high-frequency signals. Reducing the frequency is the only way to achieve underwater communication.

[0006] The present invention is mainly aimed at scenes with limited depth and limited area, such as swimming pools. Considering that the length, width and height of a standard swimming pool are 25 meters, 11 meters and 1.6 meters respectively. Considering the diagonal distance of the cuboid in time, it is 27.4 meters. In other words, the present invention needs to consider underwater communication methods within a maximum of 30 meters and apply them to the field of underwater wireless charging. Summary of the invention

[0007] 1. Technical problems to be solved: How to apply wireless charging to underwater communications up to 30 meters away.

[0008] 2. Technical solution: In order to solve the above problems, the present invention provides a method for underwater positioning based on megahertz communication, comprising the following steps: Step S01: Start and retrieve the database.

[0009] Step S02: Collect data at position 1, and then move forward in any direction for a random time.

[0010] Step S03: Collect data at position 2, and then move forward in any direction for a random time.

[0011] Step S04: Data collection at position 3.

[0012] Step S05: Compare the database to see if a unique location is obtained. If yes, proceed to the next step. If not, return to step S02. Step S06: Obtain the exact location of the underwater robot and establish the shortest path back to the charging pile.

[0013] The database uses a standard swimming pool as a reference. On the premise that the swimming pool is filled with fresh water, the receiving power of the receiving antenna, the operating frequency, and the transmitting antenna power are collected at different positions inside the swimming pool, including horizontally, vertically, and at depth. The database is used to simulate the above parameters of a swimming pool robot at different positions inside different swimming pools.

[0014] The agricultural and industrial data in the data collection include the transmitting power of the transmitting antenna, the receiving power of the receiving antenna, and the operating frequency.

[0015] The transmitting antenna has two frequency bands, which are referred to as high-frequency antenna and low-frequency antenna. The high-frequency antenna is tens of megahertz or hundreds of megahertz, while the low-frequency antenna is several megahertz.

[0016] The method for switching the high-frequency antenna and the low-frequency antenna is: Step S21: Evaluate the throughput stability rate and packet loss rate, and start adjustment.

[0017] Step S22: Compare the power with a default minimum threshold of the receiving power at the receiving end, where the minimum threshold is a default in the system.

[0018] Step S23: Determine whether it is less than the minimum threshold. If it is greater than the minimum threshold, return to step S22; if it is less than the threshold, proceed to the next step.

[0019] Step S24: Determine whether the current antenna is a low-frequency antenna. If it is not greater than the minimum threshold, proceed to step S25; if it is less than the minimum threshold, proceed to step S26.

[0020] Step S25: switch to the low frequency antenna, and then return to step S22.

[0021] Step S26: Adjust the direction within a given time, calculate the received power in real time, and stay at the direction with the maximum received power. Record the received power at the current angle in real time and compare them with each other. After a given time, adjust the angle to the direction with the maximum received power within the time. The received power at this direction must be no less than the minimum threshold.

[0022] Step S27: Determine whether the received power is greater than the normal threshold, if yes, proceed to step S29, if no, proceed to the next step.

[0023] Step S28: Determine whether the transmission power reaches the maximum value, if yes, proceed to step S29, if no, proceed to step S30.

[0024] Step S29: Increase the transmission power of the transmitting antenna. If the receiving power at the direction of maximum antenna gain is greater than the default normal threshold, the adjustment is completed.

[0025] Step S210: within a given time, within a maximum power range, increase the transmit power of the transmit antenna; if the transmit power of the transmit antenna still does not reach the maximum value, increase the transmit power within a given time.

[0026] Step S211: When the transmitting power of the transmitting antenna is increased, the receiving power of the receiving antenna is compared with the default normal threshold. If yes, proceed to step S29; if not, proceed to the next step.

[0027] Step S212: If the receiving power of the receiving antenna is still less than the default normal threshold value when the transmitting power of the transmitting antenna is increased, the adjustment fails.

[0028] In step S26, if it is already a low-frequency antenna, the antenna gain is adjusted, that is, within a given time, the antenna is adjusted to the maximum direction angle.

[0029] In step S28, if the received power at the direction of the maximum antenna gain is still less than the default normal threshold, the third priority parameter is selected, that is, the transmit power of the transmit antenna is increased, and firstly it is determined whether the transmitter is already at the maximum transmit power.

[0030] The present invention also provides an underwater wireless charging method based on megahertz communication, comprising the following steps: Step S31: recharging starts. When the battery power of the underwater device is lower than the safety value, the device starts the recharging process.

[0031] Step S32: The exact position of the underwater robot is obtained according to the underwater positioning method according to any one of claims 1 to 7, and the shortest path back to the charging pile is determined.

[0032] Step S33: Whether the recharging path is sufficiently determined. If it is determined that the recharging path is not sufficiently determined, return to step S32.

[0033] Step S34: Correct and determine the recharging path.

[0034] Step S35: Is the distance to the charging pile close enough? Determine whether the underwater device is within 1 meter of the charging pile. If the underwater device is not within 1 meter of the charging pile, return to step S32.

[0035] Step S36: Switch the high frequency antenna to further correct the route.

[0036] Step S37: Has the battery returned to the charging position? If not, return to step S36.

[0037] Step S38: In-band communication between wireless charging coils to determine charging requirements. When returning to the charging position, communication is performed through two coils, namely the wireless charging transmitter coil and the wireless charging receiver coil.

[0038] Step S39: Wireless charging starts.

[0039] In step S31, the safety value is 30%.

[0040] In step S38, after returning to the charging position, communication is performed through two coils, namely the wireless charging transmitter coil and the wireless charging receiver coil. At this time, the megahertz antenna is no longer needed for communication.

[0041] 3. Beneficial effects: The present invention applies megahertz wireless communication technology to underwater wireless charging scenarios such as swimming pools to achieve wireless communication of tens of meters, and based on this, improves positioning accuracy, optimizes the wireless charging process, and improves charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a precise positioning method based on multi-level megahertz.

[0043] Figure 2 It is a switching flow chart of a multi-speed megahertz antenna module.

[0044] Figure 3 It is a method for underwater charging of multi-speed megahertz antenna modules. DETAILED DESCRIPTION

[0045] The present invention is described in detail below with reference to the accompanying drawings.

[0046] like Figure 1 As shown, a method for underwater positioning based on megahertz communication, assuming that the data database has been completed, is used to determine the position algorithm by comparing the database. The method includes the following steps: Step S01: Start and retrieve the database.

[0047] Step S02: Collect data at position 1, and then move forward in any direction for a random time. The underwater robot records parameters including the transmitting power of the transmitting antenna, the receiving power of the receiving antenna, the operating frequency, etc. at the place marked as position 1. Then it can move forward in any direction for a short random time, such as 9 seconds.

[0048] Step S03: Collect data at position 2, and then move forward in any direction for a random time. The position at this time is marked as position 2, and the transmit power of the transmit antenna, the receive power of the receive antenna, the operating frequency and other parameters are recorded. Then you can move forward in any direction for a short random time, such as 5 seconds.

[0049] Step S04: Data collection at position 3.

[0050] Step S05: Compare the database to see if a unique location is obtained. If yes, proceed to the next step. If not, return to step S02; compare the data of the above three location markers with the database to obtain the actual location coordinates. The data of the three markers should be sufficient to ensure that the current location obtained is a unique location. If not, continue to repeat the above location point data collection.

[0051] Step S06: Obtain the exact location of the underwater robot and establish the shortest path back to the charging pile.

[0052] The database uses a standard swimming pool as a reference. When the swimming pool is filled with fresh water, it collects the receiving power, operating frequency, and transmitting antenna power of the receiving antenna at different positions inside the swimming pool, including horizontal, vertical, and deep. The database is used to simulate the above parameters of the swimming pool robot at different positions inside the swimming pool.

[0053] Specifically, the transmitting antenna position is determined and fixed, such as the northeast corner of the upper surface of a standard swimming pool. When the receiving antenna is at different positions in the standard swimming pool, the receiving power of the receiving antenna at each position of the megahertz antenna is established as a database, that is, a data database corresponding to the geographical location.

[0054] For example, the southwest corner of the bottom of a standard swimming pool is used as the zero point of the three-axis coordinates, and a certain point in the swimming pool is marked with (x, y, z) coordinates. The point is recorded relative to the fixed transmitting antenna at different operating frequencies (such as the simplified high frequency and low frequency in the present invention), different transmitting antenna powers (such as maximum power and non-maximum power), and the receiving power received by the receiving antenna. Of course, other parameters such as the antenna orientation angle and the swimming pool water quality can also be considered.

[0055] The database should be collected in advance by the product developer with reference to a standard swimming pool.

[0056] The positioning accuracy can be further improved by using multi-position MHz antennas.

[0057] In actual applications, there may be several possibilities for determining the position of the receiving antenna, that is, the swimming pool robot, by receiving the power of the receiving antenna at different gears.

[0058] Moreover, the position of the swimming pool robot can be further determined by receiving the power of the antenna when the robot moves a certain distance in a specific direction within a unit time, such as 10 seconds, and the corresponding value in the database when the robot passes through several points in the swimming pool.

[0059] The establishment of wireless communication, i.e. the strength of the received signal at the receiving end, the probability of data packet loss, the throughput of communication data, etc., basically depends on three key parameters, namely, the operating frequency, the transmission power and the antenna gain. Considering the obvious attenuation of wireless communication underwater, the above parameters need to be controlled in real time to ensure the establishment and stability of communication.

[0060] In particular, the adjustment priority of the above parameters is frequency, antenna direction and power from high to low. Putting power last is mainly to consider reducing power consumption as much as possible. At the same time, some simplified devices may not have the automatic adjustment function of antenna direction, so switching frequency is the highest priority method.

[0061] For the convenience of the principle discussion and without loss of generality, the present invention takes the two most basic frequency gears as an example to illustrate the switching method. That is, at this time, there are two frequency band antennas, referred to as high-frequency antennas and low-frequency antennas. The high-frequency antenna can be tens of megahertz or hundreds of megahertz, while the low-frequency antenna can be several megahertz.

[0062] The reason for switching antennas of different frequency bands is that wireless communication is not stable enough. This is mainly manifested in unstable data throughput per unit time, such as a change rate of more than 50%, and / or a high data packet loss rate, such as more than 30%. At this time, although wireless communication is still not interrupted, it is necessary to improve the stability of communication and reduce the throughput change rate and packet loss rate.

[0063] In one embodiment, the method of switching the high frequency antenna and the low frequency antenna is as follows: Figure 2 As shown, the following steps are included: Step S21: Evaluate the throughput stability rate and packet loss rate, and start adjustment.

[0064] Step S22: Compare the power with the default minimum threshold of the receiving end receiving power, which is the default in the system. The receiving end can calculate its own receiving power. The lower the receiving power, the weaker the signal, the higher the packet loss rate, the greater the rate of change of the throughput, and the easier the network is to be interrupted. The system has a default minimum threshold. When the receiving power is less than the threshold, the network may be interrupted. Therefore, the purpose of this algorithm is to improve the receiving power.

[0065] Step S23: Determine whether it is less than the minimum threshold. If it is greater than the minimum threshold, return to step S22, and the receiving end continues to evaluate the throughput stability rate, packet loss rate and its own receiving power in real time. If it is less than the threshold, proceed to the next step.

[0066] Step S24: Determine whether the current antenna is a low-frequency antenna. If it is not greater than the minimum threshold, the low-frequency antenna should be switched first to expand its transmission distance. Therefore, it is determined here whether it is already a low-frequency antenna and enters step S25. If it is less than the minimum threshold, it enters step S26.

[0067] Step S25: switch to the low-frequency antenna. If the current antenna is a high-frequency antenna, switch to the low-frequency antenna, and then return to step S22.

[0068] Step S26: Adjust the direction within a given time, calculate the received power in real time, and stay at the direction with the maximum received power. Record the received power at the current angle in real time and compare them with each other. After a given time, adjust the angle to the direction with the maximum received power within the time. The received power at this direction must be no less than the minimum threshold.

[0069] Step S27: Determine whether the received power is greater than the normal threshold, if yes, proceed to step S29, if no, proceed to the next step.

[0070] Step S28: Determine whether the transmit power has reached the maximum value. If yes, proceed to step S29; if no, proceed to step S30. If the received power at the maximum antenna gain direction is still less than the default normal threshold, only the third priority parameter can be selected, that is, increasing the transmit power of the transmit antenna. Here, first determine whether the transmitter is already at the maximum transmit power.

[0071] Step S29: Increase the transmission power of the transmitting antenna. If the receiving power at the direction of maximum antenna gain is greater than the default normal threshold, the adjustment is completed.

[0072] Step S210: within a given time, within a maximum power range, increase the transmit power of the transmit antenna; if the transmit power of the transmit antenna still does not reach the maximum value, increase the transmit power within a given time.

[0073] Step S211: When the transmitting power of the transmitting antenna is increased, the receiving power of the receiving antenna is compared with the default normal threshold. If yes, proceed to step S29; if not, proceed to the next step.

[0074] Step S212: If the receiving power of the receiving antenna is still less than the default normal threshold value when the transmitting power of the transmitting antenna is increased, the adjustment fails.

[0075] The present invention also provides an underwater wireless charging method based on megahertz communication. In order to preserve the generality, the present invention takes the two most basic frequency levels as an example. That is, at this time, there are two frequency band antennas, referred to as high-frequency antennas and low-frequency antennas. The high-frequency antenna can be tens of megahertz or hundreds of megahertz, while the low-frequency antenna can be several megahertz. Figure 3 As shown, the specific steps include: Step S31: recharging starts. When the battery power of the underwater device is lower than a safe value, such as 30% of the battery power, the device starts the recharging process, that is, it customizes a shortest path, returns to the charging pile, and starts wireless charging.

[0076] Step S32: precise positioning algorithm: The underwater precise positioning method proposed by the underwater positioning method based on megahertz communication determines the recharging path.

[0077] Step S33: Whether the recharging path is sufficiently determined. If it is determined that the recharging path is not sufficiently determined, the precise positioning algorithm is continued to be executed.

[0078] Step S34: Correct and determine the recharging path. Repeat the above method to correct and determine the recharging path.

[0079] Step S35: Is the distance to the charging pile close enough? Determine whether the underwater device is within 1 meter of the charging pile.

[0080] Step S36: Switch the high-frequency antenna to further correct the route. In order to further optimize the homing accuracy, at this time, the transmitting antenna and the receiving antenna will switch to the high-frequency antenna, and the transmitting antenna will increase the transmission power to further optimize the recharging path.

[0081] Step S37: Has the battery returned to the charging position? If not, repeat the previous instruction.

[0082] Step S38: In-band communication between wireless charging coils to determine charging requirements. When returning to the charging position, communication can be carried out through two coils, namely the wireless charging transmitter coil and the wireless charging receiver coil. At this time, the megahertz antenna is no longer needed for communication.

[0083] Step S39: Wireless charging starts.

Claims

1. A method for underwater positioning based on megahertz communication, characterized in that: The following steps are involved: Step S01: Start, retrieve the database; Step S02: collect data at position 1, and then move forward in any direction for a random time; Step S03: collect data at position 2, and then move forward in any direction for a random time; Step S04: collecting data at position 3; Step S05: Compare the database to see if a unique location is obtained. If yes, proceed to the next step. If not, return to step S02. Step S06: Obtain the exact location of the underwater robot and establish the shortest path back to the charging pile.

2. The underwater positioning method based on megahertz communication as claimed in claim 1, characterized in that: The database uses a standard swimming pool as a reference. On the premise that the swimming pool is filled with fresh water, the receiving power of the receiving antenna, the operating frequency, and the transmitting antenna power are collected at different positions inside the swimming pool, including horizontally, vertically, and at depth. The database is used to simulate the above parameters of a swimming pool robot at different positions inside different swimming pools.

3. The underwater positioning method based on megahertz communication as claimed in claim 1, characterized in that: The agricultural and industrial data in the data collection include the transmitting power of the transmitting antenna, the receiving power of the receiving antenna, and the operating frequency.

4. The method for underwater positioning based on megahertz communication as claimed in claim 3, characterized in that: The transmitting antenna has two frequency bands, which are referred to as high-frequency antenna and low-frequency antenna. The high-frequency antenna is tens of megahertz or hundreds of megahertz, while the low-frequency antenna is several megahertz.

5. The method for underwater positioning based on megahertz communication as claimed in claim 4, characterized in that: The method for switching the high-frequency antenna and the low-frequency antenna is: Step S21: Evaluate the throughput stability rate and packet loss rate, and start adjustment; Step S22: comparing the power with a default minimum threshold of the receiving end receiving power, where the minimum threshold is a default in the system; Step S23: Determine whether it is less than the minimum threshold. If it is greater than the minimum threshold, return to step S22. If it is less than the threshold, proceed to the next step. Step S24: determining whether the current antenna is a low-frequency antenna; If it is not greater than the minimum threshold, proceed to step S25; if it is less than the minimum threshold, proceed to step S26; Step S25: switch to the low frequency antenna, and then return to step S22; Step S26: Adjust the direction within a given time, calculate the received power in real time, stay at the direction with the maximum received power, record the received power of the current angle in real time, compare them with each other, and after a given time, adjust the angle to the direction with the maximum received power within the time. The received power at this direction must not be less than the minimum threshold; Step S27: Determine whether the received power is greater than the normal threshold, if yes, proceed to step S29, if no, proceed to the next step; Step S28: Determine whether the transmission power reaches the maximum value, if yes, proceed to step S29, if no, proceed to step S30; Step S29: Increase the transmission power of the transmitting end antenna. If the receiving power at the direction of maximum antenna gain is greater than the default normal threshold, the adjustment is completed. Step S210: increasing the transmit power of the transmit antenna within the maximum power range within a given time. If the transmit power of the transmit antenna still does not reach the maximum value, increasing the transmit power within the given time; Step S211: When the transmitting power of the transmitting antenna is increased, the receiving power of the receiving antenna is compared with the default normal threshold, if yes, proceed to step S29, if no, proceed to the next step; Step S212: If the receiving power of the receiving antenna is still less than the default normal threshold value when the transmitting power of the transmitting antenna is increased, the adjustment fails.

6. The underwater positioning method based on megahertz communication as claimed in claim 5, characterized in that: In step S26, if it is already a low-frequency antenna, the antenna gain is adjusted, that is, within a given time, the antenna is adjusted to the maximum direction angle.

7. The underwater positioning method based on megahertz communication as claimed in claim 5, characterized in that: In step S28, if the received power at the direction of the maximum antenna gain is still less than the default normal threshold, the third priority parameter is selected, that is, the transmit power of the transmit antenna is increased, and firstly it is determined whether the transmitter is already at the maximum transmit power.

8. An underwater wireless charging method based on megahertz communication, characterized in that: The following steps are involved: Step S31: recharging starts, the battery power of the underwater device is lower than the safety value, and the device starts the recharging process; Step S32: obtaining the exact position of the underwater robot according to the underwater positioning method according to any one of claims 1 to 7, and determining the shortest path back to the charging pile; Step S33: whether the recharging path is determined to be sufficient, if it is determined that the recharging path is not determined to be sufficient, return to step S32; Step S34: Correct and determine the recharging path; Step S35: Is the distance to the charging pile close enough? Determine whether the underwater device is within 1 meter of the charging pile. If the underwater device is not within 1 meter of the charging pile, return to step S32. Step S36: Switch the high frequency antenna to further correct the route; Step S37: Has the battery returned to the charging position? If not, return to step S36; Step S38: In-band communication between wireless charging coils to determine the charging demand. When returning to the charging position, communication is performed through two coils, namely, the wireless charging transmitter coil and the wireless charging receiver coil; Step S39: Wireless charging starts.

9. The underwater wireless charging method based on megahertz communication according to claim 8, characterized in that: In step S31, the safety value is 30%.

10. The underwater wireless charging method based on megahertz communication according to claim 8, characterized in that: In step S38, after returning to the charging position, communication is performed through two coils, namely the wireless charging transmitter coil and the wireless charging receiver coil. At this time, the megahertz antenna is no longer needed for communication.

Images