Patent Publication Number: US-2019187728-A1

Title: Automatic following apparatus and automatic following system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This non-provisional application claims priority under 35 U.S.C. § 119(a) to Patent Application No. 201711368889.9 filed in China, P.R.C. on Dec. 18, 2017, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a mobile apparatus, and in particular, to an automatic following apparatus and an automatic following system. 
     Related Art 
     As information networks flourish, hardware devices in people&#39;s life can be remotely controlled by using a network. For example, various hardware can be connected to the Internet for information exchange and communication by using an information sensor device (for example, a wireless sensor node, a radio frequency (RF) identification apparatus, or an infrared sensor) according to a protocol agreed in advance, thereby implementing remote control and management. 
     However, in the current high-tech society, many things still need to be done manually. For example, when shopping in a store, people have to push a cart with their hands. For another example, when needing to follow other vehicles during driving, people have to control a steering wheel, also with their hands, to control the movement of their own vehicles. For still another example, people have to drag a suitcase by themselves when travelling abroad. 
     SUMMARY 
     In view of this, in an embodiment, an automatic following system is provided, including a target apparatus and a following apparatus. The target apparatus includes a first magnetometer, a first processing unit, and a first wireless communications unit. The first magnetometer keeps transmitting geomagnetic azimuth information. The first processing unit is connected to the first magnetometer and the first wireless communications unit. The first processing unit receives the geomagnetic azimuth information and outputs first direction angle information. The first direction angle information is an angle between a current advancing direction of the target apparatus and the Geomagnetic axis. The first wireless communications unit transmits a wireless signal comprising the first direction angle information. The following apparatus includes a second magnetometer, a second processing unit, a second wireless communications unit, and a control unit. The second magnetometer keeps transmitting the geomagnetic azimuth information. The second wireless communications unit is communicatively connected to the first wireless communications unit and receives the wireless signal. The second processing unit is connected to the second magnetometer and the second wireless communications unit. The second processing unit receives the geomagnetic azimuth information and generates second direction angle information. The second direction angle information is an angle between the following apparatus and the Geomagnetic axis, and the second processing unit calculates following steering angle information according to the first direction angle information and the second direction angle information. The control unit is connected to the second processing unit, and the control unit receives the following steering angle information and controls, according to the following steering angle information, the following apparatus to steerably advance. 
     In an embodiment, an automatic following apparatus is provided, including a magnetometer, a wireless communications unit, a processing unit, and a control unit. The magnetometer keeps transmitting geomagnetic azimuth information. The wireless communications unit keeps receiving an external wireless signal, where the external wireless signal includes first direction angle information. The processing unit is connected to the magnetometer and the wireless communications unit. The processing unit keeps receiving the geomagnetic azimuth information and generates second direction angle information according to the geomagnetic azimuth information. The second direction angle information is an angle between the automatic following apparatus and the Geomagnetic axis. The processing unit calculates following steering angle information according to the first direction angle information and the second direction angle information. The control unit is connected to the processing unit, and the control unit receives the following steering angle information and controls, according to the following steering angle information, the automatic following apparatus to steerably advance. 
     Based on the above, in the automatic following system and the automatic following apparatus in the embodiments of the present disclosure, the geomagnetic azimuth information of the Earth is measured by using the magnetometer, and a advancing azimuth of the target apparatus is obtained according to the geomagnetic azimuth information. Because the azimuth includes information about angle and direction, the following apparatus can calculate, according to the geomagnetic azimuth information and the advancing azimuth of the target apparatus, the steering angle of following the target apparatus, so that the following apparatus steerably advances according to the steering angle and implements automatic following. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an embodiment of an automatic following system; 
         FIG. 2  is a partial three-dimensional view of an embodiment of a following apparatus; 
         FIG. 3  is a schematic diagram showing following of an embodiment of an automatic following system; 
         FIG. 4  is a schematic diagram showing application of an embodiment of an automatic following system; 
         FIG. 5  is a schematic diagram showing application of another embodiment of an automatic following system; 
         FIG. 6  is a block diagram of another embodiment of a following apparatus; and 
         FIG. 7  is a schematic diagram showing steering correction of an embodiment of an automatic following system. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a block diagram of an embodiment of an automatic following system according to the present disclosure. In this embodiment, the automatic following system  1  includes a target apparatus  10  and a following apparatus  20 . In some embodiments, the target apparatus  10  is a movable apparatus. For example, the target apparatus  10  may be an apparatus capable of automatic moving, such as an automatic aircraft, a self-propelled vehicle, or a self-propelled machine. Alternatively, the target apparatus  10  may be an apparatus capable of moving when manually controlled, such as a remote control plane, an automobile, or a bicycle. Further, alternatively, the target apparatus  10  may be a wearable apparatus or a portable apparatus capable of moving along with the movement of a human body, such as a watch, a hand ring, a mobile phone, a tablet computer, a backpack, or clothes. 
     In the embodiment of  FIG. 1 , the target apparatus  10  includes a first magnetometer  11 , a first processing unit  12 , and a first wireless communications unit  13 . The first magnetometer  11  can keep transmitting geomagnetic azimuth information A. For example, the first magnetometer  11  may be specifically a micro magnetometer, which is also referred to as an electronic compass (E compass), and is mainly used for measuring a magnetic field azimuth of the North Pole of the Earth, to obtain the geomagnetic azimuth information A. For example, the first magnetometer  11  may obtain, by means of measurement, the geomagnetic azimuth information A by using the Hall effect or the magnetoresistance effect of a magnetic material. In an embodiment, the first magnetometer  11  may be designed into a three-axis magnetometer or a planar magnetometer according to an actual requirement. 
     As shown in  FIG. 1 , the first processing unit  12  in the target apparatus  10  is connected to the first magnetometer  11  and the first wireless communications unit  13 . In some embodiments, the first processing unit  12  may be hardware capable of computing, such as a central processing unit (CPU), a programmable microprocessor, a digital signal processor (DSP), a programmable controller, an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or another similar apparatus. The first processing unit  12  can receive the geomagnetic azimuth information A transmitted by the first magnetometer  11  and output first direction angle information θ 1 . The first direction angle information θ 1  is an angle between a current advancing direction of the target apparatus  10  and the Geomagnetic axis. For example, assuming that the first magnetometer  11  detects that a geomagnetic azimuth shown in the geomagnetic azimuth information A (that is, an azimuth of the North Geomagnetic Pole) is 0°, the first processing unit  12  can calculate an angle (for example, 20°, 30°, or 50°) between the current advancing direction of the target apparatus  10  and the North Geomagnetic Pole. In this embodiment and the following embodiments, the North Geomagnetic Pole is used as reference of angle measurement. 
     Further, as shown in  FIG. 1 , the first wireless communications unit  13  can wirelessly transmit a wireless signal W comprising the foregoing first direction angle information θ 1 . The first wireless communications unit  13  may be specifically an antenna unit, a WiFi unit, a 3G/4G unit, or an RF unit, to wirelessly transmit a signal to the outside. 
     In an embodiment, each element (the first magnetometer  11 , the first processing unit  12 , and the first wireless communications unit  13 ) in the target apparatus  10  may be separately disposed. For example, the first magnetometer  11 , the first processing unit  12 , and the first wireless communications unit  13  are independent elements and are separately disposed in the target apparatus  10 . Alternatively, the elements in the target apparatus  10  may be disposed in a combined manner. For example, the first magnetometer  11 , the first processing unit  12 , and the first wireless communications unit  13  are integrated on a same circuit board and disposed in the target apparatus  10 . 
     As shown in  FIG. 1 , in an embodiment, the following apparatus  20  is a movable apparatus. For example, the following apparatus  20  may be an apparatus that has a driving element (for example, a wheel or a rotor wing) and that can be actuated, such as an aircraft, an automobile, a suitcase, a cart, or a model vehicle. In the embodiment of  FIG. 1 , the following apparatus  20  includes a second magnetometer  21 , a second processing unit  22 , a second wireless communications unit  23 , and a control unit  24 . 
     As shown in  FIG. 1 , the second magnetometer  21  in the following apparatus  20  may also be an E compass for measuring the magnetic azimuth of the North Pole of the Earth, to obtain and transmit the geomagnetic azimuth information A. The second wireless communications unit  23  is communicatively connected to the first wireless communications unit  13 . For example, the second wireless communications unit  23  may be specifically an antenna unit, a WiFi unit, a 3G/4G unit, or an RF unit, to wirelessly receive the wireless signal W transmitted by the first wireless communications unit  13 . 
     As shown in  FIG. 1 , the second processing unit  22  in the following apparatus  20  is connected to the second magnetometer  21  and the second wireless communications unit  23 . The second processing unit  22  may be hardware capable of computing, such as a CPU, a programmable microprocessor, a DSP, a programmable controller, an ASIC, a PLD, or another similar apparatus. The second processing unit  22  receives the geomagnetic azimuth information A and generates second direction angle information θ 2 . The second direction angle information θ 2  is a direction angle of the following apparatus  20  relative to the North Geomagnetic Pole. For example, assuming that the second magnetometer  21  detects that a geomagnetic azimuth shown in the geomagnetic azimuth information A (that is, an azimuth of the North Geomagnetic Pole) is 0°, the second processing unit  22  can calculate an angle (for example, 20°, 30°, or 50°) between a current facing direction or advancing direction of the following apparatus  20  and the North Geomagnetic Pole. 
     In addition, the second processing unit  22  in the following apparatus  20  can calculate following steering angle information Δθ according to the first direction angle information θ 1  and the second direction angle information θ 2 . The control unit  24  of the following apparatus  20  is connected to the second processing unit  22 . The control unit  24  may be specifically hardware capable of computing, such as a CPU, a programmable microprocessor, a DSP, a programmable controller, an ASIC, a PLD, or another similar apparatus. The control unit  24  can receive the following steering angle information Δθ and control, according to the following steering angle information Δθ, the following apparatus  20  to steerably advance. 
     Specifically, because both the first direction angle information θ 1  and the second direction angle information θ 2  are direction angles relative to the North Geomagnetic Pole, the second processing unit  22  can calculate the following steering angle information Δθ according to a difference between the first direction angle information θ 1  and the second direction angle information θ 2 . For example, assuming that the first direction angle information θ 1  is 50°, and the second direction angle information θ 2  is 20°, the following steering angle information Δθ is 50°−20°=30°. The control unit  24  can control the following apparatus  20  to further steer by 30° (the following steering angle information Δθ) relative to the original direction angle of 20° (the second direction angle information θ 2 ), so that the following apparatus  20  has a direction angle of 50°, which is the same as that of the target apparatus  10 , and advances toward a direction which is the same as that of the target apparatus  10 , thereby automatically following the target apparatus  10 . 
     As shown in  FIG. 1 , in an embodiment, the following apparatus  20  may include a driving unit  25  connected to the control unit  24 . The control unit  24  can control the driving unit  25  to drive the following apparatus  20  to steerably advance. For example, assuming that the following apparatus  20  is a vehicle, the driving unit  25  may be a structure (for example, a wheel or a redirector) driving the vehicle to steerably advance. Assuming that the following apparatus  20  is an aircraft, the driving unit  25  may be a rotor wing or a motor, and so on. 
     Based on the above, in the automatic following system  1  in this embodiment of the present disclosure, the geomagnetic azimuth information A of the Earth is measured by using the magnetometer, and the advancing direction angle of the target apparatus  10  is obtained according to the geomagnetic azimuth information A, so that the following apparatus  20  can calculate the following steering angle information Δθ according to the geomagnetic azimuth information A and the advancing direction angle of the target apparatus  10 . In this way, the following apparatus  20  can steerably advance according to the following steering angle information Δθ and automatically follow the target apparatus  10 . In addition, in this embodiment, the direction angle, measured by using the magnetometer, of the North Geomagnetic Pole is used as reference for calculating the first direction angle information θ 1  and the second direction angle information θ 2 . When the direction angles are calculated according to a GPS signal, because the GPS signal is often blocked by landforms or ground objects, the accuracy is greatly reduced, and the GPS signal even cannot be used. Therefore, the automatic following system  1  in this embodiment has higher accuracy, thereby increasing the efficiency of following. 
     The following further specifically describes an actual application example of the automatic following system  1  with reference to drawings. As shown in  FIG. 2  and  FIG. 3 , an example is used in which both the target apparatus  10  and the following apparatus  20  are vehicles. The second magnetometer  21 , the second processing unit  22 , the second wireless communications unit  23 , and the control unit  24  in the following apparatus  20  may be disposed in an in-vehicle apparatus  2  (as shown in  FIG. 2 ). The target apparatus  10  may move toward an advancing direction (for example, an arrowhead L 1 ). The first magnetometer  11  in the target apparatus  10  can detect the geomagnetic azimuth information A (which is 0° herein). The first processing unit  12  can calculate the angle (that is, the first direction angle information θ 1 , which is 40° herein) between the advancing direction of the target apparatus  10  and the North Geomagnetic Pole, and wirelessly transmit the angle to the following apparatus  20  by using the first wireless communications unit  13 . The facing direction or advancing direction of the following apparatus  20  may be shown as an arrowhead L 2 . The second magnetometer  21  in the following apparatus  20  can also detect the geomagnetic azimuth information A (which is 0° herein). The second processing unit  22  can calculate the angle (that is, the second direction angle information θ 2 , which is −30° herein) between the facing direction or advancing direction of the following apparatus  20  and the North Geomagnetic Pole. The second processing unit  22  can calculate that the following steering angle information Δθ=the first direction angle information θ 1 —the second direction angle information θ 2 =70°. The control unit  24  can control the following apparatus  20  to steer clockwise by 70° relative to the original direction (for example, the arrowhead L 2 ), so that the following apparatus  20  can advance toward a direction which is the same as that of the target apparatus  10  and automatically follow the target apparatus  10 . 
     However, the foregoing embodiment is merely an example. The automatic following system  1  in the present disclosure can be applied to following other objects in addition to following vehicles. For example, as shown in  FIG. 4 , in this embodiment, the target apparatus  10  in the automatic following system  1  is a watch worn on the wrist of a user, and the following apparatus  20  is a suitcase. When the user is advancing, the target apparatus  10  is synchronously displaced. The suitcase can automatically follow the target apparatus  10 , so that the user does not need to drag the suitcase with hands, thereby increasing convenience. Alternatively, as shown in  FIG. 5 , in this embodiment, the target apparatus  10  in the automatic following system  1  is a bracelet worn on the wrist of a user, and the following apparatus  20  is a cart. When the user is shopping in a store, the cart can automatically follow the target apparatus  10 , so that the user does not need to push the cart with hands, thereby increasing convenience. 
     As shown in  FIG. 1  and  FIG. 3 , in an embodiment, the second wireless communications unit  23  can keep detecting the wireless signal W transmitted by the target apparatus  10  and output a corresponding received signal strength indicator (RSSI). The control unit  24  controls the following apparatus  20  to increase an advancing speed of the following apparatus  20  when the RSSI keeps decreasing. Specifically, the RSSI of the wireless signal W can respond to a distance between the following apparatus  20  and the target apparatus  10 . That is, a greater RSSI indicates a shorter distance between the following apparatus  20  and the target apparatus  10 , and a smaller RSSI indicates a longer distance between the following apparatus  20  and the target apparatus  10 . Therefore, in a process in which the following apparatus  20  follows the target apparatus  10 , a smaller RSSI of the wireless signal W indicates that the advancing speed of the following apparatus  20  is inadequate, so that the control unit  24  increases the advancing speed of the following apparatus  20 . 
     Alternatively, as shown in  FIG. 1  and  FIG. 3 , in an embodiment, in the process in which the following apparatus  20  follows the target apparatus  10 , a smaller RSSI of the wireless signal W may represent that the advancing direction of the following apparatus  20  is wrong, so that the second processing unit  22  in the following apparatus  20  re-calculates the following steering angle information Δθ, to avoid a wrong following. 
     Further, referring to  FIG. 6  and  FIG. 7 ,  FIG. 6  and  FIG. 7  show an embodiment. This embodiment is different from the embodiment of  FIG. 1  in that following apparatuses are different. A second wireless communications unit  23  in a following apparatus  20 ′ in this embodiment further includes a first signal receiving unit  231  and a second signal receiving unit  232 . The first signal receiving unit  231  and the second signal receiving unit  232  are respectively disposed on two opposite sides (which are a right side and a left side of a vehicle) of an advancing direction (for example, shown as an arrowhead L 3  in  FIG. 7 ) of the following apparatus  20 ′. In a process in which the following apparatus  20 ′ follows a target apparatus  10 ′, the first signal receiving unit  231  can detect a wireless signal W and correspondingly output a first RSSI, and the second signal receiving unit  232  can detect the wireless signal W and correspondingly output a second RSSI. In the embodiment of  FIG. 7 , because the target apparatus  10 ′ is on the right of the following apparatus  20 ′, and the first signal receiving unit  231  is closer, than the second signal receiving unit  232 , to the target apparatus  10 ′, the first RSSI is greater than the second RSSI. The second processing unit  22  can receive the first RSSI and the second RSSI, and learn, based on that the first RSSI is greater than the second RSSI, that the target apparatus  10 ′ is on the right of the following apparatus  20 ′, so that the second processing unit  22  generates correction angle information θ 3 . The correction angle information θ 3  is a steering correction angle by which the following apparatus  20 ′ steers to the side of the first signal receiving unit  231 . A control unit  24  can control, according to both the following steering angle information Δθ and the correction angle information θ 3 , the following apparatus  20 ′ to steerably advance. For example, referring to  FIG. 3  and  FIG. 7 , the following apparatus  20 ′ steers by 70° (the following steering angle information Δθ) before advancing toward a direction which is the same as that of the target apparatus  10 ′. In the process in which the following apparatus  20 ′ follows the target apparatus  10 ′, assuming that the target apparatus  10 ′ is on the right of the following apparatus  20 ′, the control unit  24  can control, according to the correction angle information θ 3 , the following apparatus  20 ′ to steer by a rightward correction angle (the correction angle information θ 3  is 40° herein), so that the following apparatus  20 ′ can follow right behind the target apparatus  10 ′. 
     Although the present disclosure has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope of the disclosure. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope and spirit of the disclosure. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.