WO2020037584A1

WO2020037584A1 - Sectional type automatic charging docking method and mobile device and charging station

Info

Publication number: WO2020037584A1
Application number: PCT/CN2018/101877
Authority: WO
Inventors: 张举中; 储雨奕; 蔡黎明
Original assignee: 永康国科康复工程技术有限公司
Priority date: 2018-08-23
Filing date: 2018-08-23
Publication date: 2020-02-27
Also published as: CN111465908B; CN111465908A

Abstract

A sectional type mobile device automatic charging docking method. When detecting a low battery of the mobile device or receiving a manual charging command (S101), the mobile device determines whether the device is in a precisely positioned area (S102), and if not, estimates a relative position between the mobile device and the charging station on the basis of a dead reckoning method and an ultra-wideband positioning technology, or a positioning technology based on receiving signal strength, and drives the mobile device to move toward the charging station (S103) till entering the precisely positioned area; when being in the precisely positioned area, the mobile device starts an ultrasonic positioning mode, and sends an ultrasonic positioning instruction to the charging station (S104), obtains a relative pose between the mobile device and the charging station estimated in real time by using a wireless synchronization signal and an ultrasonic signal, and drives the mobile device to move toward the charging station, wherein the relative pose comprises position information and angle information (S105). The method achieves good balance in aspects such as efficiency, accuracy, a power consumption, hardware costs, algorithm complexity, and environmental adaptation.

Description

Segmented autonomous charging docking method, mobile device and charging station

Technical field

The invention relates to the field of autonomous charging of mobile devices, and in particular, to a method for autonomous charging docking of segmented mobile devices.

Background technique

Autonomous docking charging means that mobile devices (such as mobile robots) can autonomously switch to the charging mode when the battery is insufficient, autonomously find a charging device, and automatically charge after the battery terminal is docked with the charging device socket. There are currently four commonly used methods for autonomous charging docking: infrared guidance, visual guidance, laser guidance, and a combination of infrared guidance and ultrasonic positioning.

Infrared guidance is to install an infrared emitting device with a certain half-power angle on the charging device, and install an infrared receiving device around the mobile device. The charging device guides the mobile device to complete the charging docking task by always transmitting the infrared guiding signal. Because of its low cost and easy implementation, this method is widely used in mobile devices, such as home cleaning robots. However, this method also has many disadvantages, such as inability to achieve precise positioning.

Visual guidance is to mark the charging device, install a camera on the mobile device, use image processing algorithms to identify the location of the charging device, and guide the mobile device to achieve charging docking. Although this method has high positioning accuracy, the algorithm is complex, the cost is high, and the influence of ambient light intensity is large.

Laser guidance is to install a lidar on a mobile device, use synchronous positioning and map creation algorithms to accurately locate the position of the charging device, and guide the mobile device to complete the charging docking. This method has the advantages of strong autonomy and high positioning accuracy, but the algorithm is complicated, the hardware resources are required, and the cost is high, and the implementation is difficult.

The combination of infrared and ultrasonic guidance refers to the use of a combination of infrared signals and ultrasonic guidance signals to complete the charging docking. This technical solution usually installs the infrared signal receivers on both sides of the mobile device. By determining that the infrared signal receivers on both sides can receive the guidance signal at the same time to complete the horizontal positioning, the distance from the charging device is measured by the ultrasonic tube. Whether they are equal to complete the vertical positioning. In practice, this solution has the problems of low positioning efficiency and insufficient accuracy.

technical problem

In order to solve the problems existing in the prior art including complicated algorithms, high costs, and low positioning accuracy, the present invention provides a segmented autonomous charging docking method and a mobile device and charging station implementing the same in terms of efficiency, accuracy, and power. A good balance has been achieved in power consumption, hardware cost, algorithm complexity, and environmental adaptability.

Technical solutions

To achieve the above-mentioned object, the present invention adopts the following technical solutions:

A segmented autonomous charging docking method applied to a mobile device includes:

When the mobile device detects that its own battery power is low or receives an artificial charging command, it determines whether the mobile device is in the precise positioning area. If not, it uses dead reckoning algorithms, ultra-wideband positioning technology, or positioning technology based on the received signal strength to estimate the mobile device. The relative position with the charging station, driving the mobile device to move to the charging station until entering the precise positioning area;

When the mobile device is in the precise positioning area, start the ultrasonic positioning mode, send an ultrasonic positioning instruction to the charging station, obtain the relative position between the mobile device and the charging station estimated in real time using the wireless synchronization signal and the ultrasonic signal, and drive based on the relative position The mobile device moves towards the charging station until it reaches a set charging posture, wherein the relative posture includes position information and angle information.

Further, the method for determining the set charging posture includes: comparing the relative posture information between the mobile device and the charging station estimated in real time with a set value, and the set value includes a position threshold and an angle threshold; or by determining The manner of contact is determined.

Further, the method for judging contact includes: judging whether a contact button provided on a charging station or a mobile device is pressed, or detecting whether a charging electrode of the charging station is connected to a charging electrode of the mobile device.

Further, the specific manner of judging whether the mobile device is in a precise positioning area is:

After the mobile device detects that its own battery is low or receives an artificial charging command, it sends a charging preparation instruction to the charging station to determine whether it has received the infrared signal emitted by the charging station. If it is, it is in the precise positioning area. If not, it is not in the precise positioning area. Positioning area.

Further, the process of moving the mobile device to the charging station further includes:

Determine whether the movement direction encounters an obstacle, and if so, start the wall mode, that is, keep a certain distance between the mobile device and the obstacle, and move along the obstacle until it avoids the obstacle.

Further, before entering the precise positioning area, the ultrasonic module of the mobile device is in a spontaneous self-receiving mode, that is, an obstacle avoidance mode, which is used to determine whether an obstacle is encountered in the direction of movement. The distance between obstacles is constant, and move along the obstacles until you avoid them.

Further, when the mobile device is in the precise positioning area, the ultrasonic positioning mode is activated, the ultrasonic module is set to the receiving mode, and whether the infrared signal is received during the process of moving to the charging station, and if not, the ultrasonic module is set It is a spontaneous self-receiving mode, that is, an obstacle avoidance mode. It sends a stop positioning guidance instruction to the charging station, and starts a walk along the wall mode until it avoids obstacles.

Further, using the wireless synchronization signal and the ultrasonic signal to estimate the relative position and posture between the mobile device and the charging station in real time may be specifically:

The charging station and the mobile device are used as the ultrasonic transmitter and the other as the ultrasonic receiver. The transmitter sends a wireless synchronization signal to the receiver, and cooperates with the wireless synchronization signal to control at least two ultrasonic modules installed on the transmitter to send ultrasonic signals in turn. The synchronization signal contains the identification information of the corresponding ultrasonic module; the receiver starts timing after receiving the wireless synchronization signal, records the time parameters of each of the at least two ultrasonic modules installed on the receiver, and receives the time parameters; calculated based on the time parameters The relative position between the mobile device and the charging station.

Further, the calculation of the relative pose is based on two ultrasound modules installed on the sender and two ultrasound modules installed on the receiver.

Further, assuming that the coordinate system X _I Y _I of the charging station is fixedly connected to the inertial coordinate system, and the coordinates of the two ultrasonic modules on the charging station are T ₁ (-a, 0) and T ₂ (a, 0), then The connecting line T ₁ T ₂ is the X _I axis, the midpoint of the two is the coordinate origin O, the X _I OY _I coordinate system is parallel to the horizontal plane, and the Y _I axis rotates 90 ° counterclockwise around the X _I axis; defines the mobile device The coordinate system X _R Y _R is fixedly connected to the mobile device. The coordinates of the two ultrasound modules on the mobile device are R ₁ (-b, 0) and R ₂ (b, 0). The center of the two is the origin of the coordinate system O _R The connection line R ₁ R ₂ is the X _R axis, the X _R O _R Y _R and X _I OY _I coordinate systems are coplanar, the angle θ between X _R and X _I is the azimuth, and the counterclockwise is defined as positive;

Assuming all ultrasound modules are at the same height or in the same plane, let the pose vector of the mobile device in the inertial coordinate system be (x, y, θ) ^T , and the coordinates of R ₁ and R ₂ in the inertial coordinate system be (x ₁ , y ₁ ), (x ₂ , y ₂ ), then:

From formulas (1) and (2), we can find

Using formulas (3) to (8), calculate the relative pose (x, y, θ) ^T between the mobile device and the charging station, where the distances d ₁₁ , d ₁₂ , d ₂₁ , d ₂₂ are obtained based on time parameters .

A mobile device for implementing a segmented autonomous charging docking method includes a controller, a battery, a walking driving mechanism, an area determination module, at least two ultrasonic modules, and a wireless communication module. Each module is connected to the controller; The area determination module is used to obtain information about whether the mobile device is in a precise positioning area.

Further, the area determination module is an infrared receiver.

A segmented autonomous charging docking method applied to a charging station includes the following steps:

After receiving the instruction sent by the mobile device, if it is a charging instruction, a precise positioning area is generated. If it is an ultrasonic positioning instruction, it cooperates with the mobile device to complete the following actions until the mobile device completes the charging docking:

The charging station and the mobile device are used as the ultrasonic transmitter and the other as the ultrasonic receiver. The transmitter sends a wireless synchronization signal to the receiver, and cooperates with the wireless synchronization signal to control at least two ultrasonic modules installed on the transmitter to send ultrasonic signals in turn. The synchronization signal contains the identification information of the corresponding ultrasonic module; the receiver starts timing after receiving the wireless synchronization signal, and records the time parameters of each of the at least two ultrasonic modules installed on the receiver to receive the ultrasound.

Further, the precise positioning area is generated using an infrared transmitter installed at a charging station.

Further, the charging station is used as the ultrasonic transmitter and the mobile device is used as the ultrasonic receiver. When the charging station receives the positioning stop guidance instruction sent by the mobile device, it stops sending ultrasonic signals.

A charging station for implementing a segmented autonomous charging docking method includes a controller, an area identification module, at least two ultrasonic modules, and a wireless communication module, each module is connected to the controller; wherein the area identification module is used for Generate pinpointed areas.

Further, the area identification module is an infrared transmitter.

Beneficial effect

The invention divides the autonomous charging docking of the mobile device into two phases, namely a rough positioning phase and an accurate positioning phase. In the initial stage when the mobile device moves to the charging station, the dead reckoning algorithm, ultra-wideband positioning technology or positioning based on the received signal strength is used. Technology, etc. guides the mobile device to the charging station quickly and conveniently, and in the later stage (after entering the precise positioning area), the ultrasonic positioning method with high positioning accuracy is used to achieve the precise positioning of the rear section. This method of combining the rough positioning of the front section and the precise positioning of the rear section has achieved a good balance in terms of efficiency, accuracy, power consumption, hardware cost, algorithm complexity, and environmental adaptability. The ideal way.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a segmented autonomous charging docking method applied to a mobile device according to an embodiment of the present invention; FIG.

2 is a segmented autonomous charging docking method applied to a mobile device according to another embodiment of the present invention;

3 is a segmented autonomous charging docking method applied to a mobile device according to another embodiment of the present invention;

4 is a segmented autonomous charging docking method applied to a mobile device according to another embodiment of the present invention;

5 is a schematic diagram of a positioning system for a mobile device and a charging station;

FIG. 6 is a flowchart of an ultrasonic transmission interruption program;

7 is a flowchart of an ultrasonic receiving program;

8 is a schematic diagram of a case where an ultrasonic module is included on a mobile device or a charging station;

9 is a segmented autonomous charging docking method applied to a charging station according to an embodiment of the present invention, where the charging station is used as an ultrasonic transmitter;

10 is a segmented autonomous charging docking method applied to a charging station according to another embodiment of the present invention, where the charging station is used as an ultrasonic receiver;

FIG. 11 is a mobile device implementing a segmented autonomous charging docking method;

FIG. 12 is a charging station that implements a segmented autonomous charging docking method.

Embodiments of the invention

The solution of the present invention will be described in detail through specific embodiments below. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. All other embodiments obtained by those skilled in the art without paying any creative labor belong to the protection scope of the present invention.

Example 1:

As shown in FIG. 1, a segmented autonomous charging docking method applied to a mobile device includes the following steps:

S101: The mobile device detects that its own battery power is low or receives an artificial charging command.

In specific implementation, the mobile device may compare the detected self battery power with a threshold, and when it is less than or equal to the threshold, determine that the self battery power is low. It may also be that the operator sends an artificial charging command to the mobile device when charging is needed.

S102: Determine whether the mobile device is in a precise positioning area. If not, execute S103, and if so, execute S104.

S103: Adopt dead reckoning algorithm, ultra-wideband positioning technology or positioning technology based on received signal strength to estimate the relative position between the mobile device and the charging station, and drive the mobile device to move to the charging station; after one movement is completed, return to S102.

The mobile device first determines whether it is in the precise positioning area. When not in the precise positioning area, it uses dead reckoning algorithm, ultra-wideband wireless positioning technology or positioning technology based on the received signal strength to estimate the relative position between itself and the charging station. Driving the mobile device body to the charging station is a more appropriate setting; of course, once the mobile device detects that its own battery is low or receives an artificial charging command, it first uses the dead reckoning algorithm, ultra-wideband positioning technology, or based on receiving Signal strength positioning technology etc. estimates the relative position between itself and the charging station, drives the mobile device body to move toward the charging station, and then determines whether the mobile device is in the precise positioning area, which is also feasible.

The one displacement mentioned here can generate a variety of solutions according to the design of those skilled in the art. For example, the person skilled in the art can set the mobile device to move for a certain period of time according to the relative posture, then end the movement, and return to determine whether the mobile device is accurate. Positioning area; after the mobile device moves a certain displacement according to the relative posture, it can end a movement and return to determine whether the mobile device is in the precise positioning area. These simple variants are all within the normal design range of those skilled in the art.

S104: Activate the ultrasonic positioning mode, and the mobile device sends an ultrasonic positioning instruction to the charging station.

S105: Obtain a relative pose between the mobile device and the charging station that is estimated in real time by using a wireless synchronization signal and an ultrasonic signal, and drive the mobile device to move to the charging station based on the relative pose, where the relative pose includes position information and angle information.

S106: Determine whether the mobile device has reached the set charging posture. If yes, perform S107; if not, return to S105.

Specifically, the set charging posture includes a set position threshold and an angle threshold, and the relative posture information between the mobile device and the charging station obtained in real time is compared with the set value to determine whether the mobile device has reached the device. Fixed charging posture.

Of course, you can also determine by contact whether the mobile device has reached the set charging posture, for example, whether the contact button set on the charging station is pressed, or whether the electrodes of the charging station are connected to the relevant electrodes of the mobile device. ,and many more.

S107: The mobile device stops moving and completes autonomous docking.

In the solution of this embodiment, the autonomous charging docking of the mobile device is divided into two phases, namely, a coarse positioning phase and an accurate positioning phase. In the rough positioning phase, a dead reckoning algorithm, ultra-wideband positioning technology, or positioning technology based on received signal strength is used to estimate the relative position between the mobile device and the charging station, and the mobile device body is driven to move to the charging station based on the relative position. The mobile device uses the dead reckoning algorithm to estimate the position only based on the sensor it carries, which is simple to implement, but the position error estimated using this method will increase as the mileage increases; ultra-wideband positioning technology requires a tag on the mobile device. There are multiple positioning nodes in the mobile space. The positioning node is fixed at a certain position in the system. The positioning node records the TOA (Time of Arrival) value from the positioning node to the tag. This data will be transmitted to the mobile device. Positioning is based on mobile devices, but UWB positioning technology generally cannot determine the angle information, so it cannot be used for accurate positioning. Positioning technologies based on the strength of the received signal, such as Bluetooth positioning, WI-FI positioning, etc., are simple to locate, but are susceptible to other signals. Interference, and the positioning error is large. Therefore, in the early stage of the solution, the mobile device is guided by the dead reckoning algorithm or the ultra-wideband positioning technology or the positioning technology based on the received signal strength to guide the mobile device to the charging station quickly and conveniently. (After entering the precise positioning area), the ultrasonic positioning method with high positioning accuracy is used to realize the precise positioning of the rear section. This method of combining the rough positioning of the front section and the precise positioning of the rear section has achieved a good balance in terms of efficiency, accuracy, power consumption, hardware cost, algorithm complexity, and environmental adaptability. The ideal way.

Example 2:

As shown in FIG. 2, on the basis of the foregoing embodiments, in this embodiment, a specific manner of judging whether the mobile device is in a precise positioning area is:

After the mobile device detects that its battery is low or receives an artificial charging command, it sends a charging preparation instruction to the charging station, and then determines whether it has received the infrared signal emitted by the charging station. If it is, it is in the precise positioning area. If not, it is not in the Pinpoint the area.

Here, an infrared signal is used to generate an accurate positioning area. The area is closer to the charging station and the deviation angle from the charging station is smaller. In this area, the mobile device is suitable for precise positioning. The appropriate precise positioning area can be obtained by adjusting the divergence angle and intensity of the infrared signal. The method of generating the precise positioning area has the advantage of flexible adjustment.

Other methods can be used to generate the precise positioning area. For example, ultra-wideband (UWB) -based positioning technology requires the installation of multiple positioning nodes indoors and the installation of tags on mobile devices and charging stations, respectively. Relative position; positioning technology based on received signal strength (RSSI), such as Bluetooth positioning, WI-FI positioning, etc. can also be used to determine the relative position of the mobile device and the charging station.

Example 3:

As shown in FIG. 3, on the basis of the foregoing embodiments, in this embodiment, the process of moving the mobile device to the charging station further includes:

Avoiding obstacles in real time while the mobile device is moving to the charging station can ensure that the mobile device can smoothly approach and reach the charging station.

Further, obstacle avoidance can be achieved without adding additional sensors. Specifically, as shown in FIG. 4, before entering the precise positioning area, the ultrasonic module of the mobile device is in a spontaneous self-receiving mode, which is used to determine whether an obstacle is encountered in the direction of movement. If so, the wall mode is activated, that is, the mobile device is maintained. The distance from the obstacle is constant, and it moves along the obstacle until it avoids the obstacle. After entering the precise positioning area, the mobile device starts the ultrasonic positioning mode, sets its own ultrasonic module to the receiving mode, and moves to the charging station. In the process, it is determined whether an infrared signal is received. If not, the ultrasonic module is set to a spontaneous self-receiving mode, a stop positioning guidance instruction is sent to the charging station, and a walk-through mode is started until the obstacle is avoided.

In the above embodiment, the ultrasonic module of the mobile device has two working modes, namely, the obstacle avoidance mode in the spontaneous and self-receiving state and the positioning mode in the receiving state; when the ultrasonic module is switched from the positioning mode to the obstacle avoidance mode, charging is performed. The station sends a stop positioning guidance instruction to stop the charging station from transmitting ultrasonic waves, which can prevent interference from being introduced to obstacle avoidance and ranging.

In addition, the effect of obstacle avoidance depends on the number and layout of obstacle avoidance sensors. For example, in order to avoid obstacles of different heights, sensors of different heights need to be set. In order to improve the effect of obstacle avoidance, additional obstacle avoidance sensors can be set up with The combination of ultrasonic modules. In this case, setting the obstacle avoidance mode of the ultrasonic module reduces the number of obstacle avoidance sensors.

Example 4:

Based on the above embodiments, in this embodiment, estimating the relative position between the mobile device and the charging station based on the dead reckoning algorithm may further be estimating the relative position between the mobile device and the charging station based on the dead reckoning algorithm. For a mobile device using two-wheel drive, it can be:

Using the inertial coordinate system, define the pose of the mobile device at the k-1th sampling period as [x (k-1), y (k-1), θ (k-1) ^T ], at the kth sampling period The pose is [x (k), y (k), θ (k) ^T ], then its position and direction can be expressed by the following equations:

Among them, △ s (k) and △ θ (k) respectively represent the displacement increment and direction increment of the mobile device during the k-th sampling period, which are determined by the following formula:

Among them, U _l and U _r are displacement increments of the left and right wheels of the mobile device obtained by the angle sensor in one sampling period, and D is the distance between the two wheels. The angle sensors are installed on the left and right wheels of the mobile device. Specifically, the angle sensor may be an encoder, such as a photoelectric encoder or a magnetic encoder.

For other mobile devices, sensors such as odometers and accelerometers can be used to obtain displacement information, and electronic compasses, gyroscopes, etc. can be used to obtain angle information. Positioning can also be based on dead reckoning algorithms.

In order for the mobile device to obtain its own initial position in a convenient way, a fixed coordinate system can be established by using the position of the ultrasonic module of the charging station as a reference. If the mobile device is located near the charging station during initialization, an ultrasonic positioning algorithm is used to calculate the mobile device. The position of the fixed coordinate system relative to the charging station is used as the initial position; if the mobile device is far away from the charging station during initialization and cannot receive ultrasonic signals, the mobile device is caused to cruise on its own, and updates itself when it can receive the signal from the charging station The position relative to the charging station is used as the initial position.

Example 5:

Based on the above embodiments, in this embodiment, the relative position and posture between the mobile device and the charging station are estimated in real time by using the wireless synchronization signal and the ultrasonic signal, which may specifically be:

When the charging station receives the ultrasonic positioning instruction sent by the mobile device, the charging station uses the wireless communication module to send a wireless synchronization signal to the mobile device, and cooperates with the wireless synchronization signal to control at least two ultrasonic modules installed on the charging station as an ultrasonic transmitter. The ultrasonic signals are transmitted in turn, and the wireless synchronization signal includes identification information of the corresponding ultrasonic transmitter. The mobile device starts timing after receiving the wireless synchronization signal, records the time parameters of each of the at least two ultrasonic modules installed on the mobile device as ultrasonic receivers, and combines the information of the speed of sound to calculate each ultrasonic wave. The distance between the transmitter and each ultrasonic receiver, through the geometric relationship, further calculates the relative pose between the mobile device and the charging station.

The number of ultrasonic transmitters on the charging station is two, and the number of ultrasonic receivers on the mobile device is two.

As shown in Figure 5, in the mobile device autonomous charging docking system, the coordinate system X _I Y _{I of the} charging station is fixedly connected to the inertial coordinate system, and the coordinate of the ultrasonic transmitter T ₁ is defined as (-a, 0). The ultrasonic transmitter The coordinate of T ₂ is (a, 0), then the straight line T ₁ T ₂ is the X _I axis; correspondingly, the coordinate system X _R Y _R defining the mobile device is fixedly connected to the mobile device, and the ultrasonic receiver R ₁ (-b, The centers of 0) and R ₂ (b, 0) are the origin of the coordinate system, the straight line R ₁ R ₂ is the X _R axis, and the angle θ between X _R and X _I is the azimuth (the definition is positive counterclockwise). Wherein, a is an ultrasonic wave transmitting nodes T _1, T ₂ from the coordinate origin O X _{_I} Y _I, b is the receiving node R _1, R ₂ to a distance of _{R & lt} O.

Assuming that the ultrasonic transmitter and the ultrasonic receiver are at the same height or in the same plane, define the pose vector of the mobile device in the inertial coordinate system as (x, y, θ) ^T , and the coordinates of R ₁ and R ₂ in the inertial coordinate system are (x ₁ , y ₁ ), (x ₂ , y ₂ ), the measurement model of the positioning system can be expressed as:

From formulas (1) and (2), we can find

Through formulas (3) to (8), based on the d ₁₁ , d ₁₂ , d ₂₁ , and d ₂₂ obtained from the measurement, the relative pose (x, y, θ) ^T between the mobile device and the charging station can be calculated in real time ^. , And then guide the mobile device to complete the autonomous charging docking. It should be noted that formulas (3) to (8) are only a calculation method based on mathematical model formulas (1) and (2). The calculation method should also be within the protection scope of the present invention.

In order to measure d ₁₁ , d ₁₂ , d ₂₁ , d ₂₂ in real time, the wireless communication module on the charging station, the two ultrasonic transmitters, the wireless communication module on the mobile device, and the two ultrasonic receivers work together. For example, a specific embodiment may be: a charging station wireless communication module transmit wireless synchronization signals to the mobile device, an ultrasonic transmitter T ₁ transmits ultrasonic signals, wherein the radio synchronization signal includes an ultrasonic transmitter T identifier ID ₁ _1, the mobile device through which the After the wireless communication module receives the wireless synchronization signal, it starts timing, and respectively obtains the counting times N ₁₁ and N ₁₂ when the two ultrasonic receivers receive the ultrasonic signal. After the interval ΔT of the charging station, the wireless communication module sends the wireless communication module to the mobile device. The wireless synchronization signal and the ultrasonic transmitter T ₂ transmit ultrasonic signals. The wireless synchronization signal includes the identification ID _{2 of the} ultrasonic transmitter T _2. After receiving the wireless synchronization signal through its wireless communication module, the mobile device starts timing and acquires two ultrasonic waves respectively. counting the number N when the ultrasonic signal received by the receiver _21, N _22; In 2ΔT cycle power plant, the process is repeated.

The sending process of a wireless synchronization signal and an ultrasonic signal of a charging station can be implemented by an interrupt response program of its controller, as shown in FIG. 6. In order to distinguish the signals sent by different ultrasonic transmitters, the transmission method is adopted here instead of the multi-frequency method (that is, the signal frequency of different ultrasonic transmitters is different). Although the multi-frequency method can be used for multiple ultrasonic transmitters at the same time Sending has high efficiency, but it also requires that the ultrasonic receiver can receive signals of different frequencies, the signal processing is more complicated, and the implementation cost is high; compared with that, the alternate transmission method is simple to implement and the hardware requirements are also low.

A process for receiving an ultrasonic signal of a mobile device may be implemented by a program of a controller of the mobile device, as shown in FIG. 7. Assuming that the identification code in the received wireless synchronization signal is ID ₁ , it is determined that the acoustic wave transmitter T ₁ sends an ultrasonic signal, and it is calculated that d ₁₁ = T ₁ R ₁ = v × t ₁ = v × N ₁₁ × t ₀ , d ₁₂ = T ₁ R ₂ = v × t ₂ = v × N ₁₂ × t ₀ , where v is the speed of sound, and N ₁₁ and N ₁₂ are the number of times when the ultrasound receivers R ₁ and R ₂ receive the ultrasound , T ₀ is the counting period of the timer. In view of the fact that the propagation speed of a radio signal is much faster than the speed of sound and the propagation time within a limited distance is extremely short, the propagation time of the wireless synchronization signal is not considered in the above calculation. The time when the ultrasonic signal starts to be transmitted.

Here, the number of ultrasonic transmitters on the charging station is 2 and the number of ultrasonic receivers on the mobile device is 2, for example. However, in the actual implementation process, the number of transmitters or receivers can be increased, and only the formula ( The number of constraint equations in 1) is sufficient, and the more the number of transmitters or receivers, the higher the positioning accuracy and the better the robustness.

It should be noted that the number of ultrasonic transmitters is 2 and the number of ultrasonic receivers on the mobile device is 2 is the minimum configuration of the solution. At this time, the movement is achieved by the relative position relationship between the straight line T ₁ T ₂ and the straight line R ₁ R ₂ Docking of the device with the charging station. On this basis, if the number of ultrasonic transmitters or ultrasonic receivers is further reduced, positioning requirements cannot be met, and accurate positioning cannot be achieved. Specifically refer to FIG. 8 (a). This is the case where the number of ultrasonic transmitters on the charging station is 2, and the number of ultrasonic receivers on the mobile device is 1. During the ultrasonic positioning process, it is necessary to establish the ultrasonic nodes on the charging station. The fixed coordinate system of the charging station. When there are two (or more than two) ultrasonic transmitting nodes on the charging station, the direction of the coordinate axis can be fixed to establish a fixed coordinate system. When there is an ultrasonic receiving node on the mobile device, the movement can be calculated. The position of the device in the fixed coordinate system, but the azimuth (or orientation) of the mobile device cannot be calculated, that is, the three mobile device poses in FIG. 8 (a) cannot be distinguished, so that accurate docking cannot be achieved. Referring again to FIG. 8 (b), this is the case where the number of ultrasonic transmitters on the charging station is 1, and the number of ultrasonic receivers on the mobile device is 2. The mobile device is in three positions in the figure (alongside the ultrasonic receiving node (With a radius circle distribution), the ultrasonic ranging information is the same, that is, when there is only one ultrasonic transmitting node on the charging station, the distance between the transmitting node and the receiving node can only be measured, and the angle information cannot be measured. Figure 8 The three mobile device poses in (b) cannot be distinguished, so accurate docking cannot be achieved.

In addition, it should be noted that in the foregoing solution, the ultrasonic transmitter is installed on the charging station and the ultrasonic receiver is installed on the mobile device. Actually, the opposite setting can also be performed, that is, the ultrasonic transmitter is installed on the mobile device and the ultrasonic receiver is installed. It is set on the charging station. At this time, the relative position between the mobile device and the charging station is estimated in real time by using wireless synchronization signals and ultrasonic signals.

When the charging station receives the ultrasonic positioning instruction sent by the mobile device, the charging station is ready to receive ultrasonic signals (such as setting the ultrasonic module as a receiving module to make it an ultrasonic receiver); the mobile device uses the wireless communication module to send to the charging station Send a wireless synchronization signal and control at least two ultrasonic modules installed on the mobile device as ultrasonic transmitters to transmit an ultrasonic signal in cooperation with the wireless synchronization signal. The wireless synchronization signal includes identification information of the corresponding ultrasonic transmitter. The charging station starts timing after receiving the wireless synchronization signal, records the time parameters of each ultrasonic wave received by each of the at least two ultrasonic modules installed on the charging station, and combines the information of the speed of sound to calculate each ultrasonic wave. The distance between the transmitter and each ultrasonic receiver, through the geometric relationship, further calculates the relative pose between the mobile device and the charging station.

At this time, the ultrasonic transmission interruption program shown in FIG. 6 can be applied to the controller of the mobile device, and the ultrasonic signal reception program shown in FIG. 7 can be applied to the controller of the charging station.

After the charging station calculates the relative pose between the mobile device and the charging station, the relative pose information can be sent to the mobile device, so that the mobile device drives the mobile device to move to the charging station based on the information; of course, the charging station also The timing information or other related intermediate processing information may be sent to the mobile device, and the mobile device obtains the relative position information after further processing. These simple variations are all within the scope of the conventional design of those skilled in the art.

Example 6:

As shown in FIG. 9, it is a part of a main program flow of a controller of a charging station that involves charging docking, and provides a segmented autonomous charging docking method applied to the charging station, including the following steps:

S901: determine whether an instruction sent by the mobile device is received, if yes, execute S902, and if not, return to S901;

S902: Determine whether the instruction is a ready-to-charge instruction, if yes, execute S903, and if not, execute S904;

S903: controlling the infrared transmitter to emit infrared signals;

S904: determine whether the instruction is an ultrasonic positioning instruction, if yes, execute S905, and if not, execute S908;

S905: Start the ultrasonic transmission interruption program;

S906: Determine whether the mobile device has completed the charging docking, or whether it has received a stop positioning guidance instruction, and if one of them is satisfied, execute S907; otherwise, return to S906;

S907: Close the ultrasonic transmission interruption program;

S908: Go to other parts of the main program.

The above process is the case where the charging station is used as the ultrasonic transmitter. FIG. 10 corresponds to the case where the charging station is used as the ultrasonic receiver. The flowchart has clearly shown the operation process and will not be described again.

Among them, determining whether the mobile device has completed charging docking may be that the charging station receives the positioning stop guidance instruction sent by the mobile device and makes a judgment based thereon, or the charging station itself uses the relative posture data to compare and set the posture to make a judgment. These are all within the scope of conventional design by those skilled in the art.

The charging station can also turn off the ultrasonic transmitter / ultrasonic receiver after judging that the mobile device has finished charging and docking, and turn off the infrared transmitter when using the infrared transmitter to save energy consumption and prolong the service life of the device.

Example 7:

As shown in FIG. 11, a mobile device that implements a method of docking autonomous charging and docking is provided. The mobile device includes a controller, a battery, a walking driving mechanism, an area determination module, at least two ultrasonic modules, and a wireless communication module. Controller connected. Among them, the area determining module is used to obtain information about whether the mobile device is in a precise positioning area, and specifically, it may be an infrared receiver. The mobile device may further include a displacement determination module. The displacement determination module is configured to obtain displacement information of the mobile device, which may be an angle sensor provided on a wheel; and may further include a tag for implementing ultra-wideband-based positioning.

As shown in FIG. 12, a charging station for implementing a segmented autonomous charging docking method is provided. The charging station includes a controller, an area identification module, at least two ultrasonic modules, and a wireless communication module. Each module is connected to the controller. The area identification module is used to generate a precise positioning area, which may be an infrared transmitter.

Although the preferred embodiments of the present application have been described, those skilled in the art can make other changes and modifications to these embodiments once they know the basic inventive concepts. Therefore, the following claims are intended to be construed to include the preferred embodiments and all changes and modifications that fall within the scope of this application.

Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

A segmented autonomous charging docking method applied to a mobile device, comprising:

When the mobile device detects that its own battery power is low or receives an artificial charging command, it determines whether the mobile device is in the precise positioning area. If not, it uses dead reckoning algorithms, ultra-wideband positioning technology, or positioning technology based on the received signal strength to estimate the mobile device. The relative position with the charging station, driving the mobile device to move to the charging station until entering the precise positioning area;

When the mobile device is in the precise positioning area, start the ultrasonic positioning mode, send an ultrasonic positioning instruction to the charging station, obtain the relative position between the mobile device and the charging station estimated in real time using the wireless synchronization signal and the ultrasonic signal, and drive based on the relative position The mobile device moves towards the charging station until it reaches a set charging posture, wherein the relative posture includes position information and angle information.
The charging docking method according to claim 1, wherein the method for determining that the charging position is reached comprises: comparing the relative posture information between the mobile device and the charging station estimated in real time with a set value, and setting The fixed value includes the position threshold and the angle threshold; or it is determined by judging the contact.
The charging docking method according to claim 2, wherein the method of determining contact comprises: determining whether a contact button provided on a charging station or a mobile device is pressed, or detecting a charging electrode of the charging station and the mobile device Whether the charging electrodes are connected.
The charging docking method according to claim 1, wherein the specific way of determining whether the mobile device is in a precise positioning area is:

After the mobile device detects that its own battery is low or receives an artificial charging command, it sends a charging preparation instruction to the charging station to determine whether it has received the infrared signal emitted by the charging station. If it is, it is in the precise positioning area. If not, it is not in the precise positioning area. Positioning area.
The charging docking method according to claim 1, wherein the process of moving the mobile device to the charging station further comprises:

Determine whether the movement direction encounters an obstacle, and if so, start the wall mode, that is, keep a certain distance between the mobile device and the obstacle, and move along the obstacle until it avoids the obstacle.
The charging docking method according to claim 1, wherein before entering the precise positioning area, the ultrasonic module of the mobile device is in a spontaneous self-receiving mode, that is, an obstacle avoidance mode, for determining whether an obstacle is encountered in the direction of movement. , Then start the wall mode, that is, keep a certain distance between the mobile device and the obstacle, and move along the obstacle until it avoids the obstacle.
The charging docking method according to claim 4, characterized in that when the mobile device is in the precise positioning area, an ultrasonic positioning mode is activated, its own ultrasonic module is set to a receiving mode, and whether to receive is determined during the process of moving to the charging station. When the infrared signal is reached, the ultrasonic module is set to the spontaneous self-receiving mode, that is, the obstacle avoidance mode, sends a stop positioning guidance instruction to the charging station, and starts the walk along the wall mode until the obstacle is avoided.
The charging docking method according to claim 1, wherein using wireless synchronization signals and ultrasonic signals to estimate the relative position between the mobile device and the charging station in real time, specifically:

The charging station and the mobile device are used as the ultrasonic transmitter and the other as the ultrasonic receiver. The transmitter sends a wireless synchronization signal to the receiver, and cooperates with the wireless synchronization signal to control at least two ultrasonic modules installed on the transmitter to send ultrasonic signals in turn. The synchronization signal contains the identification information of the corresponding ultrasonic module; the receiver starts timing after receiving the wireless synchronization signal, records the time parameters of each of the at least two ultrasonic modules installed on the receiver, and receives the time parameters; calculated based on the time parameters The relative position between the mobile device and the charging station.
The charging docking method according to claim 8, wherein the calculation of the relative pose is based on two ultrasonic modules installed on the sender and two ultrasonic modules installed on the receiver.
The charging docking method according to claim 9, characterized in that, assuming that the coordinate system X I Y I of the charging station is fixedly connected to the inertial coordinate system, the coordinates of the two ultrasonic modules on the charging station are respectively T 1 (-a, 0), T 2 (a, 0), then the connection between the two T 1 T 2 is the X I axis, the midpoint of the two is the coordinate origin O, the X I OY I coordinate system is parallel to the horizontal plane, and the Y I axis is wound around X I axis rotates 90 ° counterclockwise; defines the coordinate system X R Y R of the mobile device is fixed to the mobile device. The coordinates of the two ultrasound modules on the mobile device are R 1 (-b, 0), R 2 (b, 0 ), The center of the two is the origin of the coordinate system O R , the connection between the two R 1 R 2 is the X R axis, the X R O R Y R and X I OY I coordinate systems are coplanar, the X R and X I clips The angle θ is the azimuth, which is defined as positive counterclockwise;

Assuming all ultrasound modules are at the same height or in the same plane, let the pose vector of the mobile device in the inertial coordinate system be (x, y, θ) T , and the coordinates of R 1 and R 2 in the inertial coordinate system be (x 1 , y 1 ), (x 2 , y 2 ), then:

From formulas (1) and (2), we can find

Using formulas (3) to (8), calculate the relative pose (x, y, θ) T between the mobile device and the charging station, where the distances d 11 , d 12 , d 21 , d 22 are obtained based on time parameters .
A mobile device implementing the method for segmented autonomous charging docking according to claim 1, comprising: a controller, a battery, a walking driving mechanism, an area determination module, at least two ultrasonic modules, and a wireless communication module, Each module is connected to a controller; wherein the area determining module is configured to obtain information about whether the mobile device is in a precise positioning area.
A mobile device according to claim 11, wherein the area determination module is an infrared receiver.
A segmented autonomous charging docking method applied to a charging station, which comprises the following steps: receiving an instruction sent by a mobile device, if it is preparing a charging instruction, generating a precise positioning area, and if it is an ultrasonic positioning instruction, cooperating The mobile device completes the following actions until the mobile device completes the charging docking:

The charging station and the mobile device are used as the ultrasonic transmitter and the other as the ultrasonic receiver. The transmitter sends a wireless synchronization signal to the receiver, and cooperates with the wireless synchronization signal to control at least two ultrasonic modules installed on the transmitter to send ultrasonic signals in turn. The synchronization signal contains the identification information of the corresponding ultrasonic module; the receiver starts timing after receiving the wireless synchronization signal, and records the time parameters of each of the at least two ultrasonic modules installed on the receiver to receive the ultrasound.
The charging docking method according to claim 13, wherein the precise positioning area is generated using an infrared transmitter installed at a charging station.
The charging docking method according to claim 13, wherein the charging station is used as an ultrasonic transmitter and the mobile device is used as an ultrasonic receiver, and when the charging station receives the positioning stop guidance instruction sent by the mobile device, it stops sending ultrasonic signals.
A charging station for realizing the segmented autonomous charging docking method according to claim 13, comprising: a controller, an area identification module, at least two ultrasonic modules, and a wireless communication module, each module and the controller Connection; wherein the area identification module is used to generate a precise positioning area.
A charging station according to claim 16, wherein the area identification module is an infrared transmitter.