Method and device for generating beacon signal

Abstract

The embodiment of the present invention provides a method and device for generating a beacon signal, which is used in virtual reality (VR) technology and has the characteristics of supporting high sampling rate and being able to save power consumption. The beacon signal is used to determine the position and / or orientation of a target. The device includes: a control circuit, which is used to: use a first binary control signal to control a first driver coupled to a first coil so that the first coil generates a first magnetic field; use a second binary control signal to control a second driver coupled to a second coil so that the second coil generates a second magnetic field; and use an activation circuit with a ramp response to activate the first driver.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 201810878427.X filed on August 3, 2018 and invention name “Method and device for generating beacon signals”. Technical Field

[0002] The present invention relates to virtual reality (VR) technology, and in particular to a method and device for generating a beacon signal. Background Art

[0003] VR systems are becoming increasingly popular in many applications such as video games, architectural design, and virtual training. Current VR applications, both mobile phone-based and non-mobile phone-based, generally use display devices such as computer monitors, VR headsets, and / or VR speakers to immerse users in a virtual environment using visual or audio-visual effects. In order to allow the user to interact with the virtual environment, sensors can sense information such as the position of the user's body and provide this information to the VR system to update the virtual environment based on the user's movements. Sensors that have been used in VR systems include, for example, motion tracking cameras and handheld motion tracking remote controls. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a method and apparatus for generating a beacon signal.

[0005] An embodiment of the present invention provides a device for generating a beacon signal, wherein the beacon signal is used to determine the position and / or orientation of a target, the device comprising: a control circuit for: using a first binary control signal to control a first driver coupled to a first coil so that the first coil generates a first magnetic field; using a second binary control signal to control a second driver coupled to a second coil so that the second coil generates a second magnetic field; and using an activation circuit with a ramp response to activate the first driver.

[0006] The time required for the ramp response to reach its maximum value is greater than 50 μs, and / or the ramp response includes at least two steps.

[0007] The first driver exhibits a resonant frequency response, wherein controlling the first driver coupled to the first coil using the first binary control signal comprises operating the first driver to be non-resonant.

[0008] The step of activating the first driver using the activation circuit having the ramp response includes providing a power supply voltage that increases over time to the first driver.

[0009] An embodiment of the present invention provides a device for generating a beacon signal, wherein the beacon signal is used to determine the position and / or orientation of a target, the device comprising: a first driver, coupled to a first coil, for driving the first coil to generate a first magnetic field; a second driver, coupled to a second coil, for driving the second coil to generate a second magnetic field; and an activation circuit, for activating at least one of the first driver and the second driver; wherein the first driver and the second driver both comprise: a switching amplifier, and the activation circuit has a ramp response.

[0010] Wherein, the first driver and the second driver both exhibit a resonant frequency response, and / or the time required for the ramp response to reach its maximum value is greater than 50 μs.

[0011] The invention further comprises: a control circuit coupled to the first driver and the second driver, and used for controlling the first driver and the second driver to operate in a non-resonant manner.

[0012] The activation circuit is specifically used to provide a gradually increasing power supply voltage to at least one of the first driver and the second driver.

[0013] An embodiment of the present invention provides a method for generating a beacon signal, wherein the beacon signal is used to determine the position and / or orientation of a target, the method comprising: using a first binary control signal to control a first driver coupled to a first coil so that the first coil generates a first magnetic field; using a second binary control signal to control a second driver coupled to a second coil so that the second coil generates a second magnetic field; and using an activation circuit with a ramp response to activate the first driver.

[0014] The step of activating the first driver using an activation circuit with a ramp response includes: providing a power supply voltage that increases over time to the first driver.

[0015] Wherein the first driver exhibits a resonant frequency response, wherein controlling the first driver coupled to the first coil using the first binary control signal comprises: operating the first driver to be non-resonant.

[0016] The first magnetic field and the second magnetic field are orthogonal to each other, and / or the time required for the ramp response to reach its maximum value is greater than 50 μs.

[0017] The method further includes: using a third binary control signal to control a third driver coupled to a third coil so that the third coil generates a third magnetic field; and using the drive circuit to activate the second driver and the third driver.

[0018] The method further includes: using a sensor disposed on the target to receive the first magnetic field and the second magnetic field; and determining the position and / or orientation of the target based on the received first magnetic field and the second magnetic field.

[0019] The generating of the first magnetic field and the generating of the second magnetic field include: causing the first coil to generate a first burst pulse, causing the second coil to generate a second burst pulse, and the first burst pulse and the second burst pulse do not overlap each other.

[0020] The first binary control signal has a first frequency, and the second binary control signal has a second frequency different from the first frequency.

[0021] The ramp response comprises: a plurality of steps, the plurality of steps at least comprising a first step, a second step and a third step, the first step and the second step are separated by a first time interval, the second step and the third step are separated by a second time interval, the first time interval and the second time interval have a duration inversely proportional to the fundamental frequency of the first binary control signal and / or the resonant frequency of the first coil.

[0022] The beneficial effects of the embodiments of the present invention are:

[0023] The method and device for generating a beacon signal according to the embodiment of the present invention have the advantages of low power consumption and support for a high sampling rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are not drawn to scale. In the drawings, the same or similar components in each figure are marked with the same numbers. For the purpose of simplicity, not every component is marked in every figure.

[0025] Figure 1A is a schematic diagram of a VR environment according to some non-limiting embodiments, wherein the VR environment uses magnetic induction to track the position of a user's body part;

[0026] Figure 1B is a block diagram of a system suitable for magnetically tracking the position of a body part of a user;

[0027] Figure 2 is a schematic diagram of the amplitudes of three mutually orthogonal magnetic fields and the amplitude of the magnetic field received at the sensor;

[0028] Figure 3 is a circuit diagram of a control circuit according to some non-limiting embodiments;

[0029] Figure 4 is a graph showing, according to some non-limiting embodiments, Figure 3 possible resonant response of the control circuit;

[0030] Figure 5 is a schematic diagram of current flowing through a coil when a driver is activated in one step according to some non-limiting embodiments;

[0031] Figures 6A to 6D is an example diagram of current flowing through a coil when a driver is gradually activated according to some non-limiting embodiments;

[0032] Figure 7 is a graph of a specific example of a ramp response according to some non-limiting embodiments. DETAILED DESCRIPTION

[0033] The inventors have realized and understood that the magnetic-based tracking systems currently used in VR applications either suffer from poor sampling rates or high power consumption. As a result, the market lacks many affordable products that can seamlessly track the real-time movement of body parts or other elements while also being battery-powered. Magnetic-based tracking systems are used in VR applications (such as gaming, remote surgery, multimedia, and military applications) to track the position of one or more targets in space in real time. Specifically, the position of a target can be determined by magnetic induction between a beacon placed in the surrounding environment and a sensor placed on the tracked target. The signal provided by the beacon to determine the position and / or orientation of the target is called a beacon signal.

[0034] In order to accurately track the real-time movement of a target, such as an arm, finger, or other part of the body, in some applications it is very important that the system be able to provide a sufficiently high sampling rate (i.e., the rate at which the position of the target is determined over time). For example, some applications may require sampling rates as high as 400Hz. However, one challenge associated with magnetic-based tracking systems is the balance between sampling rate and power consumption. That is, systems designed for high sampling rates generally exhibit high power consumption, making battery-powered implementations challenging. In addition, existing systems are also bulky, thereby limiting the portability of the system and, therefore, limiting the types of applications in which the system can be deployed.

[0035] Recognizing these challenges, the inventors have developed a magnetic tracking system for VR applications that has low power consumption, high sampling rate, and compact structure. Some embodiments of the present application are directly related to VR tracking systems that can achieve low power consumption by using switching amplifiers to drive magnetic transmitters. Compared to traditional linear amplifier drivers, the switching amplifiers used by the inventors can reduce the current flowing through the resistor and thus reduce power consumption.

[0036] In addition, the system developed by the inventors provides stable control of the amplitude of the magnetic field, and therefore accurate position measurement, by operating the resonance-based beacon off-resonance. Accordingly, the inventors realized that operating the beacon away from its resonance makes the amplitude of the magnetic field less susceptible to undesirable changes in the resonant frequency, which may be due to temperature, process variations, or other reasons. In fact, the frequency response is steeper in the spectral region near resonance than in the spectral region away from resonance. Therefore, undesirable changes in resonance can cause substantial changes in the amplitude near resonance, but the amplitude changes away from resonance are not severe.

[0037] One disadvantage of using switching amplifiers for non-resonant operation is that these types of amplifiers take longer to reach a steady state than linear amplifiers. In other words, switching amplifiers exhibit longer transient times during which the amplitude of the magnetic field may be too unstable to support accurate position measurement. In at least some cases, this long transient time is caused by the fact that a beating tone is caused by the non-resonant operation and that the beating tone takes a long time to decay. Specifically, the beating tone may be caused by the interference of two signals, including a tone oscillating at the resonant frequency and a drive signal that may have a fundamental frequency different from the resonant frequency.

[0038] Nevertheless, the inventors have realized that the above disadvantages can be overcome (or at least limited) by using a switching amplifier activated by a circuit with a ramp response. Examples of ramp responses include a stepped response with at least two steps. Using a circuit with a ramp response enables the switching amplifier to be activated gradually, which can accelerate the decay of the beating tone. This acceleration results in a shorter transition time. The shorter transition time in turn makes a higher sampling rate possible because the time required to accurately sample the position of the target can be reduced.

[0039] Figure 1A is a schematic diagram of a magnetic-based tracking system according to some non-limiting embodiments. Figure 1AThe left portion of shows three coils oriented along mutually orthogonal axes. Coil 102 is oriented along the x-axis, coil 104 is oriented along the y-axis, and coil 106 is oriented along the z-axis. It should be noted that other embodiments may cause the coils to be substantially orthogonal to each other (e.g., at angles between 80° and 100° to each other). The coils can be formed in any suitable manner, including, for example, by winding a conductive wire multiple times around a support. The coils can be driven by AC (alternate current), and thus a magnetic field can be emitted via electromagnetic induction. The emitted magnetic field can propagate in space and reach the location of the target being tracked. Figure 1A The right part of the diagram schematically shows the user's hand. As shown, in this case, multiple sensors 200 are set on the user's hand. Each sensor 200 can be used to track the movement of various parts of the user's body, such as fingers, palms / backs of hands, wrists, etc. Sensor 200 may include: a coil or other magnetic detector to sense the magnetic field provided by coils 102, 104 and 106. Sensor 200 can transmit a signal representing the sensed magnetic field to position tracking circuit 210. Position tracking circuit 210 is connected via a wired (such as Figure 1A As shown) or wirelessly connected to the sensor 200, wherein the wireless method includes: Wi-Fi or Bluetooth, etc. Figure 1A The sensor 200 and the position tracking circuit 210 are shown as separate components, but in other embodiments, one or more sensors 200 may include the position tracking circuit 210. For example, the sensor 200 and the position tracking circuit 210 may be provided in the same package, and the package may be provided on the target to be tracked.

[0040] Based on the amplitude of the received magnetic field, the position of the sensor 200 and, therefore, the position of the body part on which the sensor 200 is placed can be determined. In general, the amplitude of a magnetic field decays as it propagates away from its source. For example, a spherical magnetic field wave that appears in the far-field zone decays at 1 / r 2 = , where r is the distance from the source. Therefore, assuming the system has been pre-calibrated, the position of the sensor 200 relative to the source can be determined by determining the amplitude of each of the three emitted magnetic fields.

[0041] Figure 1B For implementation Figure 1A. In this case, the control circuit 110 provides an AC drive current to the coils 102, 104 and 106. The control circuit 110 may include: an amplifier and a circuit for timing the transmission of the magnetic field. The control circuit 110 and the coils 102, 104 and 106 may be collectively referred to as a beacon. Of course, the beacon may also include other elements not described herein. On the receiver side, in this case, each sensor 200 includes: a triplet of coils 202, 204 and 206, all connected to a position tracking circuit 210. The coils 202, 204 and 206 may be oriented in mutually orthogonal (or at least substantially mutually orthogonal) directions. It will be appreciated that the orientation of the coils 202, 204 and 206 may be different from the orientation of the coils 102, 104 and 106. For example, although the coils 102, 104 and 106 may be oriented in accordance with the xyz coordinate system, the coils 202, 204 and 206 may also be rotated relative to such a coordinate system. In these cases, each receiving coil receives not only one of the three transmitted magnetic fields, but may receive all of them. Therefore, determining the position of the body part relative to the beacon may involve a matrix transformation, which may be performed by the position tracking circuit 210. In addition to or in lieu of determining the position of the target, the matrix transformation may provide the orientation of the target. In fact, in some applications, it is important not only to determine the position of the target, but also to determine the orientation of the target.

[0042] Figure 1A~1B The described embodiments are such that the transmitter is fixed (beacon) and the receiver is mobile (sensor). However, in some embodiments, the opposite configuration is possible. That is, the magnetic field transmitter can be located on the body part being tracked and the receiving circuitry is located on the fixed receiver, where the matrix conversion is performed on the receiver.

[0043] Figure 2 Schematic diagram showing how the magnetic field is designed in at least some embodiments. TX , H TY , H TZ represent the amplitudes of the three emitted magnetic fields. The three magnetic fields have directions that are substantially orthogonal to each other. In one example, H TX Emitted by coil 102, H TY is emitted by coil 104, and H TZ It is emitted by coil 106. Figure 2 As shown, the magnetic field can be emitted in a burst manner. That is, H is emitted first. TX Burst pulse, followed by H TY Burst pulse, followed by H TZBurst pulses (of course the transmission order of the three bursts can be changed). ΔT1 represents the duration of the burst, which can be, for example, between 200µs and 800µs, between 200µs and 600µs, between 300µs and 500µs, between 350µs and 450µs, or between 390µs and 410µs. ΔT2 represents the interval between one burst and the next, which can be, for example, between 200µs and 600µs, between 300µs and 500µs, between 370µs and 470µs, or between 410µs and 430µs.

[0044] H RX , H RY and H RZ represents the amplitude of the magnetic field received at the sensor 200. In one example, H RX is received at coil 202, H RY is received at coil 204, H RZ is received at coil 206. In this case, coils 202, 204 and 206 are rotated relative to coils 102, 104 and 106. Therefore, each received signal is a combination of the three transmitted magnetic fields. The position of sensor 200 can be determined by solving a system of matrix transformation equations.

[0045] In at least some embodiments, synchronization of the receiver with the transmitter can be achieved by including pauses between adjacent groups of bursts. For example, a beacon may transmit the following sequence: x-burst, y-burst, z-burst, pause, x-burst, y-burst, z-burst, pause, etc. In this manner, the receiver knows that when a pause is detected, an x-burst is next.

[0046] As described above, the control circuit 110 uses an AC signal to drive the coils 102, 104, and 106. In some embodiments, the control circuit 110 can use a switching amplifier to drive the coils. A switching amplifier of the type described herein can operate as an electronic switch rather than a linear gain stage. The switching amplifier can be configured, for example, to switch between supply rails according to a control signal. Figure 3 An example circuit is shown that includes a switching amplifier and is used as the control circuit 110 in at least some embodiments.

[0047] Figure 3 The control circuit includes: drivers 302, 304 and 306. Each driver drives its own coil L x , L y and L z(respectively acting as coils 102, 104 and 106). That is, the driver provides AC current to the respective coils, and the coils generate magnetic fields in response. Driver 302 includes: transistors T1 and T2, capacitor C x , coil L x and activation circuit 322. Driver 304 includes transistors T3 and T4, capacitor C y , coil L y and activation circuit 324. Driver 306 includes transistors T5 and T6, capacitor C z , coil L z and activation circuit 326. Transistors T1 and T2 are used to receive a binary control signal V x , and thus can behave as a switching amplifier (e.g., a class D amplifier). In other configurations, transistors T1 and T2 can be configured as CMOS inverters or inverters containing bipolar transistors. BiCMOS implementations are also possible. Transistors T3 and T4 (receive binary control signal V y ) and transistors T5 and T6 (receive the binary control signal V z ) can be configured in a similar manner. Although activation circuits 322, 324, and 326 are shown as separate components, in some embodiments, multiple drivers (eg, all drivers) can share a single activation circuit.

[0048] Because the transistor receives a binary control signal, it can operate above the threshold only in the high state (e.g., when the output voltage is locked to the higher supply rail VDD). This, in turn, limits the current flowing through the transistor to certain time intervals, thereby limiting the overall power consumption of the driver. Capacitor C x and coil L x (Similarly, the capacitor C y and coil L y , capacitor C z and coil L z ) can be configured so that the driver exhibits a resonant frequency response. The resonant frequency can depend on parameters such as the capacitance of the capacitor and the inductance of the coil. For example, the resonant frequency f x0 It can be obtained by (L x C x ) -1 / 2 / 2π gives, f y0 It can be obtained by (L y C y ) -1 / 2 / 2π gives, and f z0 It can be obtained by (L z C z ) -1 / 2 / 2π is given. Figure 4A resonant response having a resonant frequency f0 is shown in FIG. Any of the drivers 302, 304, and 306 may exhibit a resonant frequency similar to Figure 4 In some embodiments, L x C x =L y C y = L z C z , although not all embodiments are limited in this regard.

[0049] In some embodiments, the driver may be driven non-resonantly. That is, the control signal V x , V y and V z The fundamental wave (f sw ) is different from the resonant frequency of the driver. Figure 4 As shown, the frequency f sw is different from (in this case, greater than) the frequency f0. The inventors will appreciate that operating the driver non-resonantly enables accurate control of the amplitude of the emitted magnetic field. In fact, the amplitude of the frequency response away from resonance is more gradual than the amplitude of the frequency response close to resonance. Therefore, the amplitude of the magnetic field is not easily affected by changes in the resonant frequency f0, such as caused by process and temperature changes. In some embodiments, the binary control signal V x , V y and V z can have different fundamental waves. For example, V x The fundamental wave is f x , V y The fundamental wave is f y , V z The fundamental wave is f z , where f x ≠f y ≠f z In a specific example, the middle fundamental wave among the three fundamental waves is equidistant from the other two fundamental waves (i.e., f x -f y =f y -f z , or f x -f y =(f x -f z ) / 2). In another specific example, the ratio of the first and second fundamental waves may be equal to the ratio of the second and third fundamental waves. y / f x =f z / f y =a, where a is a positive real number.

[0050] A drawback resulting from operating the driver off-resonance is the appearance of a beating tone that oscillates at |fsw-f0|. The beating tone may result in periodic fluctuations in the magnetic field envelope. This fluctuation is undesirable because it negatively affects the ability of the sensor 200 to determine its position. The beating tone decays over time, but the decay time may be long. This translates into a reduction in the maximum rate at which the position of the sensor 200 can be sampled. The inventors have appreciated that by activating the bursts in a gradual manner (e.g., using a circuit with a ramp response), the transition time of the beating tone can be substantially shortened.

[0051] Reference Figure 3 The driver further includes activation circuits 322, 324, and 326. In some cases, the activation circuits may all be implemented in the same manner, although not all embodiments are limited in this respect. The activation circuits are used to gradually couple the driver to the power rail V DD . For example, the activation circuit can exhibit a ramp response. The ramp response can exhibit a gradually increasing process and / or be at least partially continuous (e.g., linear). Therefore, the driver can be activated in an asymptotic manner. When the driver is gradually activated in this manner, the transition time of the beating tone is shortened. In at least some embodiments, the ramp response of the type described herein can be monotonic. In some embodiments, the ramp response can reach its maximum value when it exceeds 50μs or 100μs.

[0052] The following example shows how gradually activating the driver can shorten the duration of the beating tone. Figure 5 shows an example where the driver is not activated gradually. That is, the driver is activated directly from the lower power rail (0V) to the higher power rail (V DD ). Curve 502 represents the response of the activation circuit, which uses sudden activation. Curve 504 represents the current flowing in the coil when the driver is activated according to curve 502. As shown, the envelope of the current fluctuates due to the presence of a very slowly decaying beating tone. Although only a 500µs window is shown in this example, the steady state is only reached 2ms after the circuit is activated (the circuit is activated at t=0). That means it takes at least 2ms before the receiving sensor 200 can produce an accurate position measurement. As such, the highest sampling rate that can be obtained in this configuration is close to 166.67Hz (1 / 2ms=500Hz divided by 3, 3 being the number of bursts), which may not be sufficient in some VR applications.

[0053] Fig. 6A, 6B, 6C, and 6D show examples where the driver is gradually activated. Curves 602A, 602B, 602C, and 602D are four responses of the activation circuit. Fig. 6A In the case of the MOSFET, the higher supply rail is reached in about 140µs and 4 steps. Correspondingly, the current through the coil (604A) reaches steady state in about 400µs. Figure 6B In , the higher supply rail is reached in about 100µs and 4 steps. Correspondingly, the current flowing through the coil (604B) reaches a steady state in about 450µs. Figure 6C In the case of , the higher supply rail is reached in about 90µs and 4 steps. Correspondingly, the current (604C) flowing through the coil reaches a steady state in about 500µs. Fig.6D In the example above, the higher supply rail is reached in about 80µs and 4 steps. Correspondingly, the current (604D) flowing through the coil reaches a steady state in about 600µs. Therefore, sampling frequencies in excess of 600Hz can be obtained.

[0054] Figure 6A~6D In the described example, only one burst is shown. However, it will be appreciated that, at least in some embodiments, the gradual activation (eg, by using a circuit with a ramp response) scheme described herein may be applied to all bursts.

[0055] In the above described embodiments, the gradual activation of the driver is achieved by using the driving circuits 322, 324 and 326. However, any other scheme that can achieve the gradual activation of the driver can be used. For example, in some embodiments, the control signal V x , V y and V z Before being provided to the transistor, window functions having a ramp shape (similar to the ramp response described above) may be multiplied.

[0056] As shown, the transition time can be reduced, for example, by increasing the activation time of the driver. Other parameters that may affect the transition time include: the number of steps, the duration of each step, and the size of the discontinuities in the steps. Increasing the number of steps can further reduce the transition time, but this may also require more complex control circuits.

[0057] Figure 7 A specific example of a ramp response is shown. In this example, Step 1 jumps from 0V (at T=0) to V MAX / 2. Step 2 from V MAX / 2 jump (at T=0.5 / (f sw -f0)-0.5 / f sw to VMAX / 2+(7 / 16)V MAX Step 3 From V MAX / 2+(7 / 16)V MAX Jump (at T = 1.5 / (f sw -f0)-0.5 / f sw to V MAX / 2+(7 / 16)V MAX +(1 / 32)V MAX Step 4: From V MAX / 2+(7 / 16)V MAX +(1 / 32)V MAX Jump (at T = 2.5 / (f sw -f0)-0.5 / f sw to V MAX In some embodiments, the timing of the step jumps may deviate slightly from the above values ​​(e.g., by 10% or less or 5% or less) and / or the amplitude of the response may deviate slightly from the above values ​​(e.g., by 10% or less or 5% or less).

[0058] In general, the time interval between transitions (or at least some of all transitions) may have a value proportional to 1 / (f sw -f0), 1 / f sw , and / or duration of 1 / f0, although not all embodiments are limited in this regard. Of course, not all embodiments are limited to having Figure 7 Four steps are shown, and any other suitable number of steps may be included. It should be further noted that although the steps in FIG. 7 are illustrated as vertical segments, in some embodiments, they may have a slight inclination.

[0059] The use of ordinal terms such as "first", "second", "third", etc. to modify claimed elements in the claims does not in itself imply that one claimed element has a higher priority, precedence, or order over another, or a temporal order of the actions of the method being performed, it is merely used as a label to distinguish one claimed element with a specific name from another element with the same name (but with the use of an ordinal term) to distinguish the claimed elements.

[0060] In addition, the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," "having," "containing," or "involving" and variations thereof herein is intended to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0061] The use of "coupled" or "connected" means that circuit elements or signals are connected directly to each other or through intermediate components.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for generating a beacon signal, wherein the beacon signal is used to determine the position and / or orientation of a target, characterized in that: The method includes: The first coil generates a first magnetic field and the second coil generates a second magnetic field, wherein the first coil generates the first magnetic field and the second coil generates the second magnetic field comprises: Provide a first binary control signal to the first driver, and use the first binary control signal The first driver is controlled by a first binary control signal to provide a first current to the first coil and a first capacitor connected in series with the first coil, wherein the first binary control signal has a fundamental frequency, the series connection of the first capacitor and the first coil exhibits a resonant frequency, and the fundamental frequency is different from the resonant frequency; Provide a second binary control signal to the second driver, and use the second binary control signal The signal controls the second driver to provide a signal to the second coil and a second capacitor connected in series with the second coil. a second current; An activation circuit is used to provide a supply voltage to the first driver that increases over time.

2. The method for generating a beacon signal according to claim 1, characterized in that: The supply voltage is increased in two or more steps.

3. The method for generating a beacon signal as claimed in claim 2, characterized in that: The two or more steps occur within a period of time greater than 50µs.

4. The method for generating a beacon signal according to claim 1, wherein: The first magnetic field and the second magnetic field are orthogonal to each other.

5. The method for generating a beacon signal according to claim 1, wherein: Further including: The third coil generates a third magnetic field by providing a third binary control signal to a third driver and using the third binary control signal to control the third driver to provide a second current to the third coil and a third capacitor connected in series with the third coil.

6. The method for generating a beacon signal according to claim 1, wherein: Further including: Using a sensor disposed on the target to receive the first magnetic field and the second magnetic field; as well as The position and / or orientation of the target is determined based on at least the received first magnetic field and the second magnetic field.

7. The method for generating a beacon signal according to claim 1, wherein: The step of causing the first coil to generate a first magnetic field and causing the second coil to generate a second magnetic field further comprises: The first coil generates a first burst pulse, and the second coil generates a second burst pulse, and the first burst pulse and the second burst pulse do not overlap each other.

8. The method for generating a beacon signal as claimed in claim 2, characterized in that: The two or more steps include durations that are inversely proportional to the fundamental frequency of the first binary control signal and the resonant frequency.

9. The method for generating a beacon signal according to claim 1, wherein: The activation circuit has a ramp response.

10. A device for generating a beacon signal, wherein the beacon signal is used to determine the position and / or orientation of a target, characterized in that: The device includes: Control circuit for: The first coil generates a first magnetic field and the second coil generates a second magnetic field, wherein the first coil generates the first magnetic field and the second coil generates the second magnetic field comprises: Providing a first binary control signal to a first driver, and using the first binary control signal to control the first driver to provide a first current to the first coil and a first capacitor connected in series with the first coil, wherein the first binary control signal has a fundamental frequency, the series connection of the first capacitor and the first coil exhibits a resonant frequency, and the fundamental frequency is different from the resonant frequency; Provide a second binary control signal to the second driver, and use the second binary control signal The signal controls the second driver to provide a signal to the second coil and a second capacitor connected in series with the second coil. a second current; An activation circuit is used to provide a supply voltage to the first driver that increases over time.

11. The device for generating a beacon signal according to claim 10, characterized in that: The supply voltage is increased in two or more steps.

12. The device for generating a beacon signal according to claim 11, characterized in that: The two or more steps occur within a period of time greater than 50µs.

13. The device for generating a beacon signal according to claim 10, characterized in that: The activation circuit has a ramp response.

14. A device for generating a beacon signal, wherein the beacon signal is used to determine the position and / or orientation of a target, characterized in that: The device includes: a first driver coupled to the first coil and a second driver coupled to the second coil, wherein the first driver and the second driver exhibit a resonant frequency response, the first driver being configured to drive the first coil and a first capacitor connected in series with the first coil with a first current in response to receiving a first binary control signal having a fundamental frequency, wherein the series connection of the first capacitor and the first coil exhibits a resonant frequency, and the fundamental frequency is different from the resonant frequency, and the second driver being configured to drive the second coil and the second capacitor connected in series with the second coil with a second current in response to receiving a second binary control signal; The activation circuit is configured to provide a power supply voltage that increases over time to the first driver.

15. The device for generating a beacon signal according to claim 14, characterized in that: The first driver and the second driver include switching amplifiers.

16. The device for generating a beacon signal according to claim 14, characterized in that: Further including: A control circuit is coupled to the first driver and the second driver, and is used to control the first driver and the second driver to operate in a non-resonant manner.

17. The device for generating a beacon signal according to claim 14, characterized in that: The supply voltage is increased in two or more steps.

18. The device for generating a beacon signal according to claim 17, characterized in that: The two or more steps occur within a period of time greater than 50µs.

19. The device for generating a beacon signal according to claim 14, characterized in that: The activation circuit has a ramp response.

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