Gimbal, control method of gimbal, and photographing device

Abstract

The embodiment of the application provides a gimbal, a control method of the gimbal and a shooting device, the gimbal base of the gimbal is provided with a magnetic field generating device for generating a uniform detection magnetic field, the gimbal head of the gimbal is provided with a conductor rod, and the two ends of the conductor rod are electrically connected with a voltage detection unit; in this way, in the process that the gimbal head rotates relative to the gimbal base, the conductor rod cuts the magnetic induction lines of the detection magnetic field and generates an induced electromotive force; and the embodiment can detect the induced electromotive force at the two ends of the conductor rod through the voltage detection unit, and it can be understood that the induced electromotive force is in a positive proportional relationship with the rotational angular velocity of the conductor rod, that is, in a positive proportional relationship with the rotational angular velocity of the gimbal head, so that the rotational angular velocity of the gimbal head can be acquired, and the technical problem that the existing gimbal cannot measure the rotational speed is solved, the structure is simple, easy to implement and convenient to use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of a gimbal, and in particular to a gimbal, a control method of the gimbal and a shooting device. BACKGROUND

[0002] A gimbal is a general term of mechanical transmission, and has a wide application in the field of information collection such as video shooting, photographing and monitoring. In general, the gimbal is composed of a gimbal base and a gimbal head which are connected by rotation. A driving motor, for example, a stepping motor, is arranged in the gimbal base. The stepping motor drives the gimbal head to rotate relative to the gimbal base, so as to adjust the information collection direction of the information collection device fixed on the gimbal head. In this way, the gimbal can adjust the information collection range of the information collection device in real time and on demand, and is convenient to use.

[0003] In the prior art, the rotation angle of the gimbal head relative to the gimbal base is roughly estimated according to the number of steps of the stepping motor, and the stepping motor is prone to out-of-step phenomenon. This results in poor calculation accuracy of the rotation angle and easy rotation of the gimbal head. In addition, the existing gimbal cannot obtain the rotation speed of the gimbal head.

[0004] That is, the existing gimbal has poor precision or cannot measure the rotation angle and the rotation speed of the gimbal head, which is inconvenient for use. SUMMARY

[0005] To solve at least one of the above technical problems, the embodiments of the present application provide a gimbal, a control method of the gimbal and a shooting device. The gimbal base of the gimbal is provided with a magnetic field generating device for generating a uniform detection magnetic field. The gimbal head of the gimbal is provided with a conductor rod, and the two ends of the conductor rod are electrically connected with a voltage detection unit. In the process of the rotation of the gimbal head relative to the gimbal base, the conductor rod cuts the magnetic induction lines of the detection magnetic field and generates an induced electromotive force. The voltage detection unit can detect the induced electromotive force at the two ends of the conductor rod. It can be understood that the induced electromotive force is in a positive proportional relationship with the rotation angular velocity of the conductor rod, that is, in a positive proportional relationship with the rotation angular velocity of the gimbal head. Therefore, the rotation angular velocity of the gimbal head can be obtained, and the technical problem that the existing gimbal cannot measure the rotation speed is solved. The structure is simple, easy to implement and convenient to use.

[0006] In a first aspect, the embodiments of the present application provide a gimbal, which comprises:

[0007] a gimbal base;

[0008] a gimbal head rotationally connected with the gimbal base through a rotation shaft;

[0009] A magnetic field generating device is fixedly installed on the holder base, and generates a uniformly distributed detection magnetic field on a side facing the holder head;

[0010] A conductor rod is fixedly installed on the holder head and rotates with the holder head relative to the holder base;

[0011] The conductor rod is located on a side of the rotation shaft and extends in a radial direction of the rotation shaft, so that the conductor rod is used to cut the magnetic induction lines of the detection magnetic field when the holder head rotates relative to the holder base, and

[0012] Both ends of the conductor rod are electrically connected with a voltage detection unit, and the voltage detection unit is used to detect an induced electromotive force at both ends of the conductor rod.

[0013] In an embodiment, the magnetic induction lines of the detection magnetic field are parallel to the rotation shaft, the holder base is provided with a conductive layer on an end face facing the holder head, a first end of the conductor rod close to the rotation shaft is abutted to the conductive layer through a first conductive unit, and a second end of the conductor rod away from the rotation shaft is abutted to the conductive layer through a second conductive unit, so that the conductor rod, the first conductive unit, the conductive layer and the second conductive unit form a detection loop;

[0014] The first conductive unit and the second conductive unit are parallel to the rotation shaft, and any one of the first conductive unit, the second conductive unit and the conductor rod is connected with a detection resistor in series;

[0015] The holder further comprises:

[0016] A charge detection unit is connected in parallel with the detection resistor in the detection loop.

[0017] In an embodiment, the first conductive unit is abutted to the conductive layer through a first contact, and the second conductive unit is abutted to the conductive layer through a second contact.

[0018] In an embodiment, the detection loop further comprises a current detection unit connected in series with the detection resistor in the detection loop.

[0019] In an embodiment, the detection magnetic field is a ring-shaped magnetic field surrounding the rotation shaft, and both ends of the conductor rod extend out of the ring-shaped magnetic field.

[0020] In an embodiment, a first end of the conductor rod close to the rotation shaft extends to the rotation shaft, and the rotation shaft is hollow, and the first conductive unit is arranged inside the rotation shaft.

[0021] In an embodiment, the holder further comprises:

[0022] a control unit electrically connected with the charge detection unit and the voltage detection unit respectively;

[0023] wherein the control unit calculates the rotation angular velocity of the holder head according to the voltage detection value of the voltage detection unit, and the control unit calculates the rotation angle of the holder head according to the charge detection value of the charge detection unit.

[0024] In an embodiment, the holder further comprises:

[0025] a driving unit installed on the holder base, the driving unit being used to drive the holder head to rotate through the rotation shaft;

[0026] wherein the driving unit is electrically connected with the control unit, the control unit being used to control the rotation speed of the output shaft of the driving unit according to the voltage detection value, and the control unit being used to control the rotation angle of the output shaft of the driving unit according to the charge detection value.

[0027] In an embodiment, the holder further comprises:

[0028] a calibration unit electrically connected with the control unit;

[0029] wherein the control unit resets the rotation angle after receiving the calibration signal of the calibration unit.

[0030] In an embodiment, the magnetic field generating device is a magnet or an electromagnet.

[0031] In a second aspect, the embodiments of the present application provide a control method of a holder, the control method comprising:

[0032] obtaining a voltage detection value of a voltage detection unit;

[0033] calculating a rotation angular velocity of a holder head according to the voltage detection value;

[0034] controlling the rotation speed of an output shaft of a driving unit according to the rotation angular velocity.

[0035] In an embodiment, the control method further comprises:

[0036] obtaining a charge detection value of a charge detection unit;

[0037] calculating a rotation angle of the holder head according to the charge detection value;

[0038] controlling the rotation angle of the output shaft of the driving unit according to the rotation angle.

[0039] In an embodiment, the control method further comprises:

[0040] The rotation angle is zeroed after receiving the calibration signal of the calibration unit.

[0041] In a third aspect, the embodiments of the present application provide a shooting device, comprising a shooting device and a shooting holder bearing the shooting device, wherein the shooting holder is the holder as described above.

[0042] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0043] The holder of the embodiments of the present application comprises a holder base and a holder head connected by a rotating shaft, wherein the magnetic field generating device is installed on the holder base, and the magnetic field generating device generates a detection magnetic field towards the holder head; the conductor rod is fixedly installed on the holder head, and the conductor rod is located on one side of the rotating shaft and extends along the radial direction of the rotating shaft; it can be understood that, in the process of rotating the holder head relative to the holder base, the conductor rod rotates relative to the detection magnetic field along with the holder head, so that the conductor rod cuts the magnetic induction lines of the detection magnetic field and generates an induced electromotive force; it can be inferred that the induced electromotive force is in a proportional relationship with the angular velocity of the conductor rod, that is, in a proportional relationship with the angular velocity of the holder head; thus, the voltage detection unit is electrically connected to both ends of the conductor rod, so that the angular velocity of the conductor rod, that is, the angular velocity of the holder head, can be obtained by detecting the induced electromotive force on the conductor rod.

[0044] In other words, to solve the technical problem that the existing holder cannot obtain the rotation speed of the holder, the embodiments of the present application creatively set the detection magnetic field on the holder base and the conductor rod on the holder head, so that the angular velocity of the holder head is associated with the induced electromotive force on the conductor rod which is convenient to measure on the basis of rotating the holder head relative to the holder base; thus, the angular velocity of the holder head can be known by measuring the induced electromotive force, which is simple in structure, easy to implement, and high in detection precision, solves the technical problem that the existing holder with a stepper motor cannot know the rotation speed, and thus the holder can be precisely controlled efficiently and quickly, which is convenient to use.

[0045] In addition, the existing holder cannot complete 360-degree rotation due to structural limits, for example, it can only complete 0-degree to 359-degree rotation, at this time, if it is needed to rotate from 350-degree position to 0-degree position, it needs to be reversely rotated by a large angle, which increases the rotation time and is low in efficiency; the holder of the present application can continue to rotate across the 0-degree position without structural limits, which is high in efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0047] Figure 1 The structure schematic diagram of the holder in the embodiments of the present application.

[0048] Figure 2 The structure schematic diagram of the first conductive unit and the second conductive unit in the embodiments of the present application.

[0049] Figure 3 The equivalent circuit diagram of Figure 2

[0050] Figure 4 The bottom structure schematic diagram of the holder in the embodiments of the present application.

[0051] Figure 5 The circuit connection relationship schematic diagram of the control unit in the embodiments of the present application.

[0052] Figure 6 The flow schematic diagram of the control method of the holder in the embodiments of the present application.

[0053] In the drawings, the reference signs are as follows:

[0054] 10-Holder base, 11-Rotating shaft, 12-Magnetic field generating device, 13-Conductive layer, 14-Driving unit,

[0055] 20-Holder head, 21-Conductor rod,

[0056] 30-Detection loop, 31-First conductive unit, 32-Second conductive unit, 33-Voltage detection unit, 34-Charge detection unit, 35-Detection resistor,

[0057] 40-Control unit,

[0058] 50-Calibration unit,

[0059] X-First direction. DETAILED DESCRIPTION

[0060] In order to better understand the above technical solutions, the example embodiments of the present application will be described in detail below with reference to the drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments of the present application. It should be understood that the present application is not limited by the example embodiments described herein.

[0061] ​Gimbal is a general term for mechanical transmission, which has a wide range of applications in the field of video cameras. The gimbal camera can adjust its shooting angle to achieve flexible and multi-angle monitoring purposes.

[0062] The existing gimbal camera uses a stepper motor for control due to cost considerations, and the position and movement speed of the gimbal cannot be obtained. For example, the current rotation angle of the gimbal is mostly estimated by the number of steps of the stepper motor. In addition, the stepper motor has a phenomenon of out-of-step during movement, and there is a return difference when the rotation direction changes. These factors will cause the counting accuracy of the number of steps of the stepper motor to be low, and the rotation speed cannot be fast because the specific position and state of the gimbal are unknown, which is prone to over-rotation.

[0063] Therefore, a closed-loop gimbal driving system with high precision and reasonable price can greatly improve the real-time performance and precision of the product.

[0064] In view of the above situation, the embodiment of the present application provides a gimbal, a control method of the gimbal and a shooting device. In the embodiment, a magnetic field generating device and a conductor rod are integrated on the gimbal, and are arranged to rotate with the gimbal head during the rotation of the gimbal head relative to the gimbal base, and the conductor rod can cut the magnetic induction lines of the detection magnetic field generated by the magnetic field generating device. In this way, the rotation of the gimbal head is associated with the induced electromotive force of the conductor rod, and the induced electromotive force can be easily measured by a voltage detection unit, so that the rotation angular velocity of the gimbal head can be accurately known during the rotation of the gimbal head, and the real-time performance and measurement precision of the gimbal can be greatly improved.

[0065] Figure 1 For the structural diagram of the gimbal, please refer to Figure 1 A gimbal, the gimbal comprising a gimbal base 10, a gimbal head 20, a magnetic field generating device 12 and a conductor rod 21, the gimbal head 20 being rotationally connected to the gimbal base 10 through a rotation shaft 11; the magnetic field generating device 12 being fixedly installed on the gimbal base 10, the magnetic field generating device 12 generating a uniformly distributed detection magnetic field on the side facing the gimbal head 20; the conductor rod 21 being fixedly installed on the gimbal head 20 and rotating with the gimbal head 20 relative to the gimbal base 10; wherein the conductor rod 21 is located on one side of the rotation shaft 11 and extends along the radial direction of the rotation shaft 11; so that when rotating with the gimbal head 20 relative to the gimbal base 10, the conductor rod 21 is used to cut the magnetic induction lines of the detection magnetic field; and the two ends of the conductor rod 21 are electrically connected to a voltage detection unit 33, and the voltage detection unit 33 is used to detect the induced electromotive force at the two ends of the conductor rod 21.

[0066] The gimbal base and the gimbal head are connected by a rotating shaft, for example, along the first direction X. The gimbal head is used to install a camera or other shooting device. During the rotation of the gimbal head relative to the gimbal base, the camera or other shooting device rotates with the gimbal head, so that the camera or other shooting device can adjust its shooting angle to achieve multi-angle shooting or monitoring according to actual needs.

[0067] Specifically, in one aspect, the embodiment is installed with a magnetic field generating device on the gimbal base, which can generate a detection magnetic field on the side facing the gimbal head. In another aspect, the embodiment is installed with a conductor rod on the gimbal head, which can rotate with the gimbal head. In addition, please refer to Figure 1 The conductor rod extends along the radial direction of the rotating shaft and is located on one side of the rotating shaft. In other words, it can be understood that the conductor rod does not pass through the center (i.e. the rotating shaft) of the gimbal head from the top view.

[0068] It can be understood that when the gimbal head rotates relative to the gimbal base, the detection magnetic field is fixed relative to the gimbal base, and the conductor rod cuts the magnetic induction lines of the detection magnetic field during the rotation of the gimbal head. According to the principle of electromagnetic induction, an induced electromotive force is generated on the conductor rod. Therefore, the embodiment is also electrically connected with a voltage detection unit at both ends of the conductor rod, which is, for example, a voltmeter. The voltage detection unit can detect the induced electromotive force at both ends of the conductor rod, so as to calculate the rotational angular velocity of the conductor rod, that is, the rotational angular velocity of the gimbal head.

[0069] It can be understood that through the above setting, the embodiment can monitor the rotational angular velocity of the gimbal head in real time, that is, the rotational state of the gimbal head can be obtained in real time, so as to facilitate the on-demand control and adjustment of the rotation of the gimbal.

[0070] In addition, it should be understood that the detection magnetic field generated by the magnetic field generating device should at least cover the conductor rod on the gimbal head, which can be arranged, for example, on the end surface of the gimbal head facing the gimbal base. And considering the detection accuracy, the voltage detection unit should be outside the detection magnetic field, for example, arranged at the upper end of the gimbal head.

[0071] It should also be understood that the induced electromotive force at both ends of the conductor rod is in a proportional relationship with the rotational angular velocity of the conductor rod (i.e. the rotational angular velocity of the gimbal head), as shown in the following formula reasoning.

[0072] The gimbal of the embodiment of the application comprises a gimbal base and a gimbal head connected by a rotating shaft, wherein the magnetic field generating device is installed on the gimbal base, and the magnetic field generating device generates a detection magnetic field towards the gimbal head; the conductor rod is fixedly installed on the gimbal head, and the conductor rod is located on one side of the rotating shaft and extends along the radial direction of the rotating shaft; it can be understood that, in the process of rotating the gimbal head relative to the gimbal base, the conductor rod rotates relative to the detection magnetic field along with the gimbal head, so that the conductor rod cuts the magnetic induction lines of the detection magnetic field and generates an induced electromotive force; it can be inferred that the induced electromotive force is in a proportional relationship with the rotational angular velocity of the conductor rod, that is, in a proportional relationship with the rotational angular velocity of the gimbal head; thus, the voltage detection unit is electrically connected to both ends of the conductor rod, so that the rotational angular velocity of the conductor rod, that is, the rotational angular velocity of the gimbal head, can be obtained by detecting the induced electromotive force on the conductor rod.

[0073] In other words, to solve the technical problem that the existing gimbal cannot obtain the rotational speed of the gimbal, the embodiment creatively sets the detection magnetic field on the gimbal base and the conductor rod on the gimbal head, so that the rotational angular velocity of the gimbal head is ingeniously associated with the induced electromotive force on the conductor rod which is convenient to measure on the basis of rotating the gimbal head relative to the gimbal base, so that the rotational angular velocity of the gimbal head can be known by measuring the induced electromotive force, the structure is simple and easy to implement, and the detection precision is high, thus solving the technical problem that the existing gimbal with a stepper motor cannot know the rotational speed, so that the gimbal can be accurately controlled efficiently and quickly, and the use is convenient.

[0074] In a possible implementation, the magnetic induction lines of the detection magnetic field are parallel to the rotating shaft 11; the gimbal base 10 is provided with a conductive layer 13 on the end face facing the gimbal head 20; the first end of the conductor rod 21 close to the rotating shaft 11 is abutted to the conductive layer 13 through the first conductive unit 31, and the second end of the conductor rod 21 away from the rotating shaft 11 is abutted to the conductive layer 13 through the second conductive unit 32, so that the conductor rod 21, the first conductive unit 31, the conductive layer 13 and the second conductive unit 32 form a detection loop 30; wherein the first conductive unit 31 and the second conductive unit 32 are parallel to the rotating shaft 11; any one of the first conductive unit 31, the second conductive unit 32 and the conductor rod 21 is connected in series with a detection resistor 35; wherein the gimbal further comprises a charge detection unit 34, and the charge detection unit 34 is connected in parallel with the detection resistor 35 in the detection loop 30.

[0075] Referring to Figure 2In summary, on the basis of the conductor rod cutting the magnetic induction lines to generate the induced electromotive force, the two ends of the conductor rod are electrically connected to form a detection circuit, the detection circuit is connected in series with a detection resistor, and a charge detection unit is connected in parallel with the detection resistor. As can be inferred, the rotation angle of the conductor rod, that is, the rotation angle of the head of the holder, can be known by detecting the accumulated charge flowing through the detection resistor.

[0076] In order to ensure accuracy, that is, only the conductor rod cuts the magnetic induction lines, please refer to Figure 2 On the one hand, the magnetic induction lines of the detection magnetic field are parallel to the rotation axis, and the first and second conductive units are parallel to the rotation axis during the rotation of the head of the holder. In this way, during the rotation of the head of the holder, the first and second conductive units will not cut the magnetic induction lines to generate an induced electromotive force.

[0077] Continue to refer to Figure 2 And Figure 3 On the other hand, the conductive layer is provided on the end surface of the holder base facing the head of the holder, and the two ends of the conductor rod are respectively abutted to the conductive layer through the first and second conductive units. As can be understood, the abutment mentioned above can be achieved by a conductive elastic member, so that during the rotation of the two conductive units with the head of the holder, the detection circuit can be formed at all times, that is, the induced current flows through the detection resistor, so that the induced charge can be detected. By providing the entire end surface of the holder base as a conductive layer, the equivalent wire between the two conductive units will not cut the magnetic induction lines to generate an induced electromotive force opposite to that on the conductor rod.

[0078] In other words, the two ends of the conductor rod of the embodiment extend two conductive units respectively, the two conductive units are parallel to the rotation axis and rotate with the head of the holder, and then the two conductive units are abutted on the conductive layer on the holder base. In this way, during the rotation, on the one hand, the two conductive units will not cut the magnetic induction lines to generate an induced electromotive force, and on the other hand, the two abutment points of the two conductive units with the conductive layer also rotate with the head of the holder, so that the conduction of the detection circuit can be ensured at all times, and the equivalent wire on the conductive layer will not cut the magnetic induction lines to generate an induced electromotive force in the opposite direction.

[0079] In summary, the embodiment sets a detection circuit containing a conductor rod and ensures that only the conductor rod cuts the magnetic induction lines during rotation, so that the detection of the induced charge in the detection circuit can be realized by the charge detection unit connected in parallel with the detection resistor, so that the rotation angle of the head of the holder can be calculated, thereby efficiently and quickly controlling the holder accurately and conveniently.

[0080] It should also be understood that the charge detection value obtained by the above-mentioned charge detection unit is in a positive proportional relationship with the rotation angle of the conductor rod (i.e. the rotation angle of the head of the holder), and the details are shown in the following formula derivation.

[0081] In an embodiment, the first conductive unit 31 abuts against the conductive layer 13 through a first contact, and the second conductive unit 32 abuts against the conductive layer 13 through a second contact.

[0082] Specifically, the first contact and the second contact are, for example, metal balls arranged at the end of the conductive unit and can rotate freely, so as to facilitate rotation with the head of the holder and reduce resistance during rotation. Further, an elastic body such as a spring can be arranged between the conductive unit and the metal ball to ensure sufficient electrical connection.

[0083] In an embodiment, the detection circuit further comprises a current detection unit, and the current detection unit is connected in series with the detection resistor in the detection circuit.

[0084] The current detection unit is, for example, an ammeter, and the induced electromotive force can be calculated by combining the reading of the ammeter with the resistance value of the detection resistor. In this way, the reliability of the induced electromotive force can be ensured through double detection of the voltage detection unit and the current detection unit.

[0085] In a possible implementation, the detection magnetic field is a ring-shaped magnetic field surrounding the rotation shaft 11, and the two ends of the conductor rod 21 extend out of the ring-shaped magnetic field.

[0086] That is, considering the deviation phenomenon that may occur in the two conductive units after a long time of use, the deviation phenomenon is that the two conductive units are not parallel to the rotation shaft due to long-time rotation, thereby cutting the magnetic induction lines.

[0087] In this embodiment, the detection magnetic field is set as a ring-shaped magnetic field, and the two ends of the conductor rod extend out of the ring-shaped magnetic field, which can greatly reduce the possibility of the above-mentioned deviation phenomenon of the two conductive units, thereby cutting the magnetic induction lines, and ensure the accuracy.

[0088] Specifically, the first end of the conductor rod 21 close to the rotation shaft 11 extends to the rotation shaft 11, and the rotation shaft 11 is hollow, and the first conductive unit 31 is arranged inside the rotation shaft 11. In this way, by arranging the first conductive unit inside the rotation shaft, at least the first conductive unit can be ensured not to have the above-mentioned deviation phenomenon, and the structure is simple and easy to implement.

[0089] On the basis of the above-mentioned ring-shaped magnetic field, the following will be described in detail: the induced electromotive force at the two ends of the conductor rod is in a positive proportional relationship with the rotation angular velocity of the conductor rod, and the charge detection value is in a positive proportional relationship with the rotation angle of the conductor rod.

[0090] First, in the rotation process of the head, only the conductor rod cuts the magnetic induction lines, that is, only the area magnetic flux swept by the conductor rod changes, and an induced electromotive force E is generated on the conductor rod, and the total induced electromotive force generated on the conductor rod is:

[0091]

[0092] In formula 1, E is the induced electromotive force on the conductor rod, represents the area magnetic flux swept by the conductor rod in Δt.

[0093] Also:

[0094]

[0095] In formula 2, B represents the magnetic induction intensity of the annular magnetic field, and ΔS is the area swept by the conductor rod in the detection magnetic field.

[0096] The conductor rod cuts the annular magnetic field, and also:

[0097] ΔS = π(R 2 -r 2 )*(Δθ / 2π) = (R 2 -r 2 )*Δθ / 2 Formula 3

[0098] In formula 3, please refer to Figure 4 , r represents the inner diameter of the annular magnetic field, R represents the outer diameter of the annular magnetic field, and Δθ is the angle of rotation of the conductor rod in Δt.

[0099] Combining the above formulas 1-3 and differentiating can obtain:

[0100] E(t) = 0.5*B*(R 2 -r 2 )*dθ / dt Formula 4

[0101] In addition, also because:

[0102] ω(t) = dθ / dt Formula 5

[0103] Combining formula 4 and formula 5 can obtain:

[0104] E(t) = 0.5*B*(R 2 -r 2 )*ω(t) Formula 6

[0105] Transforming formula 6 can obtain:

[0106] ω(t) = 2*E(t) / [B*(R 2 -r 2 )] Formula 7

[0107] It can be seen from equation 7 that the induced electromotive force E at both ends of the conductor rod is in a proportional relationship with the rotational angular velocity ω of the conductor rod, and at any time, the rotational angular velocity of the conductor rod, that is, the rotational angular velocity of the head of the holder, can be calculated by measuring the induced electromotive force on the conductor rod through the voltage detection unit.

[0108] Further, integrating both sides of equation 6, We get:

[0109]

[0110] In equation 8, θ(t) represents the angle of the conductor rod rotating from the start to time t.

[0111] Since the charge detection unit is connected in parallel with the detection resistor, it can detect the cumulative charge passing through the detection resistor from the start to time t, and has:

[0112] E(t) = Z * I(t) equation 9

[0113] In equation 9, Z represents the resistance value of the detection resistor, and I represents the current flowing through the detection resistor.

[0114] Combining equation 8 and equation 9, we get:

[0115]

[0116] In equation 10, Q(t) represents the charge detection value detected by the charge detection unit from the start to time t, and it can be understood that the charge detection value represents the cumulative charge from the start to time t.

[0117] It can be seen from equation 10 that the charge detection value Q is in a proportional relationship with the rotational angle θ of the conductor rod, and at any time, the rotational angle of the conductor rod, that is, the rotational angle of the head of the holder, can be calculated by measuring the detection resistor through the charge detection unit.

[0118] Specifically, the charge detection unit described above can be a coulomb meter, which is a high-precision device with a detection accuracy of 1% for electric charge.

[0119] It can be seen from equation 7 and equation 10 that, on the one hand, the rotational angular velocity of the head of the holder can be calculated by the real-time reading E(t) of the voltage detection unit, and on the other hand, the rotational angle of the head of the holder can be calculated by the real-time reading Q(t) of the charge detection unit.

[0120] As for the determination of the rotation direction of the head of the holder, the above formula 7 represents the rotation angular velocity of the head of the holder at any time, and the direction thereof is reflected in the formula as positive and negative values. The rotation in different directions is represented by the opposite directions of the induced electromotive force and the induced current in the detection circuit, and the positive and negative values respectively indicate different directions.

[0121] In a possible implementation, the holder further comprises a control unit 40, which is electrically connected with the charge detection unit 34 and the voltage detection unit 33 respectively; wherein the control unit 40 calculates the rotation angular velocity of the head 20 of the holder according to the voltage detection value of the voltage detection unit 33, and the control unit 40 calculates the rotation angle of the head 20 of the holder according to the charge detection value of the charge detection unit 34.

[0122] That is, after receiving the voltage detection value of the voltage detection unit, the control unit calculates the rotation angular velocity of the head of the holder by the above formula 7; wherein the voltage detection value is the induced electromotive force E at both ends of the conductor rod; after receiving the charge detection value of the charge detection unit, the control unit calculates the rotation angle of the head of the holder by the above formula 10; thereby the real-time monitoring of the rotation angular velocity and the rotation angle of the head of the holder can be realized.

[0123] In an embodiment, the holder further comprises a driving unit 14, which is installed on the holder base 10, and is used to drive the head 20 of the holder to rotate through the rotation shaft 11; wherein the driving unit 14 is electrically connected with the control unit 40, and the control unit 40 is used to control the rotation speed of the output shaft of the driving unit 14 according to the voltage detection value, and the control unit 40 is used to control the rotation angle of the output shaft of the driving unit 14 according to the charge detection value.

[0124] That is, after obtaining the real-time rotation angular velocity and rotation angle of the head of the holder, the control unit can also control the driving unit according to the actual needs, so as to realize the on-demand regulation of the rotation of the head of the holder; for example, the PID algorithm can be integrated in the control unit, which can be adjusted in real time according to the speed and position of the head of the holder, quickly started, and quickly and accurately reached to the predetermined position; or the PID algorithm can also be planned in advance for the entire movement path of the head of the holder, and can be controlled in real time, which can solve the shortcoming that the traditional step motor controlled holder cannot move at high speed.

[0125] In a possible implementation, the holder further comprises a calibration unit 50, which is electrically connected with the control unit 40; wherein after receiving the calibration signal of the calibration unit 50, the control unit 40 resets the rotation angle to zero.

[0126] In this embodiment, considering that the rotation angle of the head of the holder is calculated by integration, there will be an integral error; in addition, because the above definite integral formula calculates from 0 point position 0 time, a starting position and starting time need to be provided, and the above formula can be established; based on the above two points, the calibration unit is added in this embodiment, that is, a 0 point position is added in the rotation process of the head of the holder relative to the holder base, when the conductor rod passes through this position, it is marked as 0 time, and the calculation of the previous rotation angle is cleared, so that the holder system can be calibrated and cleared regularly, and the accuracy of the data is ensured.

[0127] For example, the calibration unit is a photoelectric sensor, which includes a first calibration member and a second calibration member, the first calibration member is fixedly installed on the holder base, and the second calibration member is fixedly installed on the head of the holder, so that after each rotation of the head of the holder, the two calibration members coincide and interact, and the control unit receives the calibration signal, so as to simultaneously reset the rotation angular velocity and the rotation angle.

[0128] In a possible implementation, the magnetic field generating device 12 can be a magnet or an electromagnet.

[0129] Based on the above holder, the application further discloses a control method of the holder, please combine Figure 6 The control method comprises the following steps.

[0130] S1, obtaining a voltage detection value of a voltage detection unit;

[0131] S2, calculating a rotation angular velocity of the head of the holder according to the voltage detection value;

[0132] S3, controlling the rotation speed of the output shaft of the driving unit according to the rotation angular velocity.

[0133] In an embodiment, the control method further comprises the following steps.

[0134] S4, obtaining a charge detection value of a charge detection unit;

[0135] S5, calculating a rotation angle of the head of the holder according to the charge detection value;

[0136] S6, controlling the rotation angle of the output shaft of the driving unit according to the rotation angle.

[0137] In an embodiment, the control method further comprises the following steps.

[0138] S7, after receiving a calibration signal of the calibration unit, resetting the rotation angle.

[0139] Based on the above holder, the application further discloses a shooting device, which comprises a shooting device and a shooting holder carrying the shooting device, wherein the shooting holder is the holder as described above.

[0140] The above describes the basic principles of the present application in conjunction with specific embodiments, but it should be noted that the advantages, benefits, effects and the like mentioned in the present application are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details disclosed are only for the purpose of example and understanding, and are not limiting, and the above details do not limit the present application to be necessarily implemented with the above specific details.

[0141] The block diagrams of the devices, apparatuses, equipment, systems involved in the present application are only illustrative examples and are not intended to require or imply the connection, arrangement, configuration as shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have" and the like are open-ended words, meaning "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0142] It should also be noted that in the devices, apparatuses and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present application.

[0143] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the present application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0144] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations of the aspects and embodiments discussed above can be made without departing from the scope of the present application.

Claims

1. A gimbal, comprising: The gimbal comprises: a gimbal base; a gimbal head rotatably connected to the gimbal base through a rotating shaft; a magnetic field generating device fixedly installed on the gimbal base, the magnetic field generating device generating a uniformly distributed detection magnetic field on the side facing the gimbal head; a conductor rod fixedly installed on the gimbal head and rotating with the gimbal head relative to the gimbal base; wherein the conductor rod is located on one side of the rotating shaft and extends in the radial direction of the rotating shaft; so that when the gimbal head rotates relative to the gimbal base, the conductor rod is used to cut the magnetic induction lines of the detection magnetic field; and, both ends of the conductor rod are electrically connected with a voltage detection unit, and the voltage detection unit is used to detect the induced electromotive force at both ends of the conductor rod.

2. The head according to claim 1, characterized in that, The magnetic induction lines of the detection magnetic field are parallel to the rotating shaft; the gimbal base is provided with a conductive layer on the end face facing the gimbal head; the first end of the conductor rod close to the rotating shaft is abutted to the conductive layer through a first conductive unit, and the second end of the conductor rod away from the rotating shaft is abutted to the conductive layer through a second conductive unit, so that the conductor rod, the first conductive unit, the conductive layer and the second conductive unit form a detection loop; wherein the first conductive unit and the second conductive unit are parallel to the rotating shaft; any one of the first conductive unit, the second conductive unit and the conductor rod is connected in series with a detection resistor; wherein the gimbal further comprises: a charge detection unit, the charge detection unit is connected in parallel with the detection resistor in the detection loop.

3. The head according to claim 2, characterized in that, The first conductive unit is abutted to the conductive layer through a first contact, and the second conductive unit is abutted to the conductive layer through a second contact.

4. The head according to claim 2, characterized in that, The detection loop further comprises a current detection unit, the current detection unit is connected in series with the detection resistor in the detection loop.

5. The head according to claim 2, characterized in that, The detection magnetic field is an annular magnetic field surrounding the rotating shaft, and both ends of the conductor rod extend out of the annular magnetic field.

6. The head according to claim 5, characterized in that The first end of the conductor rod close to the rotating shaft extends to the rotating shaft, and the rotating shaft is hollow, and the first conductive unit is arranged in the interior of the rotating shaft.

7. The head according to claim 2, wherein The gimbal further comprises: a control unit, the control unit is electrically connected with the charge detection unit and the voltage detection unit respectively; wherein the control unit calculates the rotational angular velocity of the gimbal head according to the voltage detection value of the voltage detection unit, and the control unit calculates the rotational angle of the gimbal head according to the charge detection value of the charge detection unit.

8. The head according to claim 7, characterized in that, The gimbal further comprises: a driving unit installed on the gimbal base, the driving unit is used to drive the gimbal head to rotate through the rotating shaft; wherein the driving unit is electrically connected with the control unit, the control unit is used to control the output shaft speed of the driving unit according to the voltage detection value, and the control unit is used to control the output shaft angle of the driving unit according to the charge detection value.

9. The head according to claim 7, characterized in that, The gimbal further comprises: a calibration unit, the calibration unit is electrically connected with the control unit; Wherein, after receiving the calibration signal of the calibration unit, the control unit resets the rotation angle to zero.

10. The head according to claim 1, characterized in that, The magnetic field generating device is a magnet or an electromagnet.

11. A control method of a gimbal, characterized by, The control method is applied to the holder as claimed in any one of claims 1-10, and the control method comprises: acquiring a voltage detection value of a voltage detection unit; calculating a rotation angular velocity of the holder head according to the voltage detection value; controlling the rotation speed of the output shaft of the driving unit according to the rotation angular velocity.

12. The control method according to claim 11, characterized by, The control method further comprises: acquiring a charge detection value of a charge detection unit; calculating a rotation angle of the holder head according to the charge detection value; controlling the rotation angle of the output shaft of the driving unit according to the rotation angle.

13. The control method according to claim 12, characterized by, The control method further comprises: resetting the rotation angle to zero after receiving the calibration signal of the calibration unit.

14. An imaging device, characterized by comprising: The photographing device comprises a photographing holder and a photographing device carried by the photographing holder, wherein the photographing holder is the holder as claimed in any one of claims 1-10.

Images