UWB equipment capable of realizing 360-degree omnibearing positioning

Abstract

The invention discloses a UWB device capable of achieving 360-degree omnibearing positioning. The UWB device comprises a first RF coaxial connector U2, a second RF coaxial connector U4, a wireless transceiver chip and a crystal oscillator circuit. The first RF radio frequency coaxial connector U2 is connected to an RF2 pin of the wireless transceiver chip through an eighteenth capacitor C18; the second RF radio frequency coaxial connector U4 is connected to an RF1 pin of the wireless transceiver chip through a nineteenth capacitor C19; and two ends of the crystal oscillator circuit are respectively connected to an XTO pin and an XTI pin of the wireless transceiver chip. By designing a hardware circuit and optimizing links such as signal receiving, processing, positioning and tracking, the overall performance of the system is improved, and high-precision positioning and tracking capability can be ensured to be kept even in a complex environment.

Description

Technical Field

[0001] The invention belongs to the technical field of UWB positioning, and in particular relates to a UWB device capable of achieving 360-degree omnidirectional positioning. Background Art

[0002] With the widespread application of UWB (ultra-wideband) technology in the field of positioning and tracking, the omnidirectional 360° UWB base station positioning system has gradually become the core technology of high-precision indoor positioning solutions. The system uses the signal arrival phase difference positioning algorithm to achieve accurate tracking of the target. However, in practical applications, due to the system's high dependence on environmental changes, signal interference and hardware performance, how to optimize the circuit architecture to improve the system's stability, anti-interference ability and real-time performance has become a key challenge in system design.

[0003] In order to solve the above problems, the design and optimization of circuit architecture is crucial. UWB positioning system requires not only high-precision time synchronization and signal processing, but also precise RF circuits to ensure efficient transmission and reception of signals. Circuit optimization technologies such as power management, filter design, antenna matching and signal noise suppression play a decisive role in the overall performance of the system. By optimizing the circuit architecture, the power consumption of the system can be effectively reduced, and the adaptability of the system in complex environments can be enhanced, thereby improving positioning accuracy and system reliability. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0005] A UWB device capable of achieving 360-degree omnidirectional positioning, comprising: a first RF coaxial connector U2, a second RF coaxial connector U4, a wireless transceiver chip and a crystal oscillator circuit;

[0006] The first RF coaxial connector U2 is connected to the RF2 pin of the wireless transceiver chip through an eighteenth capacitor C18;

[0007] The second RF coaxial connector U4 is connected to the RF1 pin of the wireless transceiver chip through a nineteenth capacitor C19;

[0008] Two ends of the crystal oscillator circuit are respectively connected to the XTO pin and the XTI pin of the wireless transceiver chip.

[0009] Preferably, the wireless transceiver chip includes: a chip body U3, a twentieth capacitor C20, a twenty-first capacitor C21, a twenty-second capacitor C22, a twenty-third capacitor C23, a twenty-fourth capacitor C24, a twenty-fifth capacitor C25, a twenty-sixth capacitor C26, a twenty-seventh capacitor C27, a twenty-eighth capacitor C28, a twenty-ninth capacitor C29 and a magnetic bead U6;

[0010] The 20th capacitor C20 is a decoupling capacitor, one end of the 20th capacitor is connected to the VIO_D pin of the chip body U3, and the other end is grounded; one end of the 21st capacitor C21 is connected to the VTX_D pin of the chip body U3, and the other end is grounded; one end of the 28th capacitor C28 is connected to the VDD1 pin of the chip body U3, and the other end is grounded; one end of the 29th capacitor C29 is connected to the VDD2a pin of the chip body U3, and the other end is grounded;

[0011] The magnetic bead U6 is configured on the power line of the VDD2a pin, one end of the magnetic bead U6 is connected to the 3.3V power supply, and the other end is connected in parallel with the twenty-ninth capacitor C29 and then connected to the VDD2a pin of the chip body U3;

[0012] One ends of the 22nd capacitor C22, the 23rd capacitor C23 and the 24th capacitor C24 are connected in parallel to the VDD3 pin of the chip body U3 and the 3.3V power supply, and the other ends are connected in parallel to the ground;

[0013] One ends of the 25th capacitor C25, the 26th capacitor C26 and the 27th capacitor C27 are connected in parallel to the VDD2b pin of the chip body U3 and the 3.3V power supply, and the other ends are connected in parallel to ground.

[0014] Preferably, the crystal oscillator circuit comprises: a first crystal oscillator U7, a 30th capacitor C30 and a 31st capacitor C31;

[0015] The first pin of the first crystal oscillator U7 is grounded through the 30th capacitor C30, and is also connected to the XTO pin of the chip body U3;

[0016] The third pin of the first crystal oscillator U7 is grounded through the thirty-first capacitor C31, and is also connected to the XTI pin of the chip body U3;

[0017] The second pin and the fourth pin of the first crystal oscillator are directly grounded.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention improves the overall performance of the system by optimizing various links such as signal reception, processing, positioning and tracking through the design of hardware circuits, ensuring that high-precision positioning and tracking capabilities can be maintained even in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 Schematic diagram of a circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Embodiment 1

[0025] In this embodiment, if Figure 1 As shown, a UWB device capable of achieving 360-degree omnidirectional positioning includes: a first RF coaxial connector U2, a second RF coaxial connector U4, a wireless transceiver chip and a crystal oscillator circuit.

[0026] The first RF coaxial connector U2 is connected to the RF2 pin of the wireless transceiver chip through the eighteenth capacitor C18. The second RF coaxial connector U4 is connected to the RF1 pin of the wireless transceiver chip through the nineteenth capacitor C19. The two ends of the crystal oscillator circuit are respectively connected to the XTO pin and the XTI pin of the wireless transceiver chip.

[0027] In this embodiment, the first RF coaxial connector U2 and the second RF coaxial connector U4 both use the third generation test socket connector to ensure that the signal maintains low loss and high stability during high-frequency signal transmission. The first pin, the third pin and the fourth pin of the two RF coaxial connectors are all grounded. The first RF coaxial connector U2 is connected to the RF2 pin of the wireless transceiver chip through the eighteenth capacitor C18, and the second RF coaxial connector U4 is connected to the RF1 pin of the wireless transceiver chip through the nineteenth capacitor C19. The eighteenth capacitor C18 and the nineteenth capacitor C19 are used for coupling and isolation of RF signals to prevent DC current from entering the RF pin of the wireless transceiver chip, allowing high-frequency RF signals to be transmitted through capacitors to avoid DC voltage interference.

[0028] The wireless transceiver chip includes: a chip body U3, a 20th capacitor C20, a 21st capacitor C21, a 22nd capacitor C22, a 23rd capacitor C23, a 24th capacitor C24, a 25th capacitor C25, a 26th capacitor C26, a 27th capacitor C27, a 28th capacitor C28, a 29th capacitor C29 and a magnetic bead U6.

[0029] In this embodiment, the DW3220 chip is used as the chip body. In the chip, DW-IRQ is an interrupt request pin, which is used to generate an interrupt signal to notify the host of data reception, error occurrence, and task completion. DW-SYNC is a synchronization signal pin, which is used for clock synchronization to ensure that the communication of the chip is synchronized with the communication of other devices. DW-SPICSN is a chip select pin. When DW3220 communicates with other SPI peripherals, the DW-SPICSN pin will be pulled low to tell the SPI peripheral that communication is about to begin, ensuring that other peripherals will not be interfered with. DW-SPIMISO is the SPI master input slave output-master device input pin, which is used to receive data from the chip. DW-SPIMOSI is the SPI master output slave input-master device output pin, and the master device can pass data to DW3220. DW-SPICLK is the SPI clock pin, which is used to transmit the clock signal, thereby synchronizing the data transmission on the SPI bus and ensuring that the data is correctly transmitted between the master device and DW3220. DW-RS is the reset pin. When the system starts, or when the chip encounters an error or anomaly, the reset pin can be used to reinitialize the chip and restore it to normal working state. DW-WKUP is the wake-up pin. When the chip is in standby mode or deep sleep mode, the host sends a signal through the DW-WKUP pin to wake up the chip, so that it can resume work and start processing data. DW-EXTON is an external trigger input pin. The DW-EXTON pin can be used as a trigger input for external events to start wireless communication or perform certain operations. DW-GPIO0, DW-GPIO1, DW-GPIO2, DW-GPIO3, DW-GPIO4, DW-GPIO5, and DW-GPIO6 are general input / output pins.

[0030] The twentieth capacitor C20 is a decoupling capacitor, one end of which is connected to the VIO_D pin of the chip body U3, and the other end is grounded. In this embodiment, VIO_D is the I / O voltage pin of the wireless transceiver chip, which is usually used to control the logic voltage of the chip. The twentieth capacitor C20 is used to eliminate power supply noise, smooth the power supply voltage, prevent external electromagnetic interference from causing fluctuations in the VIO_D voltage, and ensure stable operation of the chip.

[0031] One end of the twenty-first capacitor C21 is connected to the VTX_D pin of the chip body U3, and the other end is grounded. In this embodiment, the VTX_D pin is a transmission data pin of the wireless transceiver chip, which is used to send radio frequency signals or control signals. Since the pin may switch signals, instantaneous current fluctuations or noise may be generated. The twenty-first capacitor C21 smoothes these current fluctuations to prevent noise from being fed back to other parts of the chip. The twenty-first capacitor C21 can eliminate high-frequency noise or voltage spikes from the VTX_D pin by grounding, ensuring that the signal of the VTX_D pin is clear and stable.

[0032] One end of the twenty-eighth capacitor C28 is connected to the VDD1 pin of the chip body U3, and the other end is grounded. In this embodiment, VDD1 is the main power supply pin of the wireless transceiver chip, which is used to provide the core voltage. The twenty-eighth capacitor C28 can reduce the voltage fluctuation caused by unstable power supply or external interference, and maintain a stable core power supply voltage.

[0033] One end of the twenty-ninth capacitor C29 is connected to the VDD2a pin of the chip body U3, and the other end is grounded. In this embodiment, VDD2a is another power pin of the wireless transceiver chip, which provides power for the auxiliary circuit. The twenty-ninth capacitor C29 reduces interference caused by external noise, ensures the stability of the VDD2a voltage, and ensures stable operation of the radio frequency.

[0034] The magnetic bead U6 is configured on the power line of the VDD2a pin, one end of the magnetic bead U6 is connected to the 3.3V power supply, and the other end is connected in parallel with the twenty-ninth capacitor C29 and then connected to the VDD2a pin of the chip body U3. In this embodiment, the model of the magnetic bead U6 is BLM03PG330SN1D. The magnetic bead U6 is configured on the VDD2a power line, one end of it is connected to the 3.3V power supply, and the other end is connected in parallel with the twenty-ninth capacitor C29 and then connected to the VDD2a pin of the wireless transceiver chip U3. While filtering, the magnetic bead can effectively suppress the high-frequency noise or interference entering the chip through the VDD2a power pin. The decoupling effect provided by the twenty-ninth capacitor C29 is combined with the anti-noise effect of the magnetic bead U6 to form a multi-level filtering and noise suppression mechanism.

[0035] One ends of the twenty-second capacitor C22, the twenty-third capacitor C23 and the twenty-fourth capacitor C24 are connected in parallel to the VDD3 pin of the chip body U3 and the 3.3V power supply to filter the noise on the VDD3 power supply and smooth out voltage fluctuations. The other ends are connected in parallel to the ground to further ensure the stable voltage and decoupling effect of the VDD3 pin.

[0036] The twenty-fifth capacitor C25, the twenty-sixth capacitor C26 and one end of the twenty-seventh capacitor C27 are connected in parallel to smooth the power supply voltage and reduce interference, noise and voltage fluctuations on the power supply; after being connected in parallel, they are connected to the VDD2b pin of the chip body U3 and the 3.3V power supply to effectively filter out high-frequency electromagnetic interference (EMI) and low-frequency power supply ripple to ensure the stability of the VDD2b power supply; the other ends are grounded after being connected in parallel.

[0037] The crystal oscillator circuit includes: a first crystal oscillator U7, a 30th capacitor C30 and a 31st capacitor C31; the first pin of the first crystal oscillator U7 is grounded through the 30th capacitor C30, and the 30th capacitor C30 is used to work together with the built-in load capacitor of the crystal oscillator to ensure that the crystal oscillator works normally at the designed frequency; the first pin is also connected to the XTO pin of the chip body U3 as the output end of the oscillation signal, which is used to stabilize the circuit; the third pin of the first crystal oscillator U7 is grounded through the 31st capacitor C31, and the 31st capacitor C31 is used to work together with the built-in load capacitor of the crystal oscillator to ensure that the crystal oscillator works normally at the designed frequency; the third pin is also connected to the XTI pin of the chip body U3 as an input end to receive the oscillation signal from the crystal oscillator; the second pin and the fourth pin of the first crystal oscillator are directly grounded.

[0038] Embodiment 2

[0039] In this embodiment, the interface of the DW3220 chip is a 4-wire SPI interface. The DW3220 chip will work as a SPI peripheral device in a non-cascade mode and support a SPI clock frequency of up to 36 MHz.

[0040] The on-chip crystal oscillator circuit generates the reference frequency of the integrated frequency synthesizer RFPLL by adding an external 38.4MHz crystal and appropriate load capacitors. The crystal oscillator circuit of the DW3220 chip is used to provide a reference clock for the internal PLL and provide a direct clock source for the digital core in the lower power INIT_RC mode. The operating frequency of the crystal oscillator circuit is 38.4MHz. The crystal oscillator circuit provides an adjustment function that can be used to correct the initial frequency error of the crystal. Using a 6-bit adjustment range, an adjustment range of ±20ppm can be achieved in steps of 0.125pF. Load capacitor size:

[0041]

[0042] Among them, C L Represents the load capacitance, C 30 and C 31 Represents the 30th capacitor and the 31st capacitor connected in parallel on both sides of the crystal.

[0043] By estimating the parasitic capacitance C between the crystal pad XTI / XTO and the crystal pad PAR, to determine the external load capacitance C EXT value to achieve balance around the center adjustment value. EXT The adjustment range is estimated by the following formula:

[0044]

[0045] Among them, f S The frequency of the crystal in series resonant mode, f P The frequency of the crystal in parallel resonant mode, f L Load frequency, L M is the series inductance of the crystal, C M is the dynamic capacitance, C0 is the intrinsic capacitance, C L is the external capacitor, C TRIM is the regulating capacitor, C PAR is the parasitic capacitance, C EXT is the external load capacitance, Δf ppm is the frequency deviation, f LNOM is the nominal load frequency.

[0046] Frequency response of a bandpass filter:

[0047]

[0048] Where f0 is the cutoff frequency, j is the imaginary unit, and f is the input signal frequency.

[0049] The digital core of the DW3000 chip is held in reset until the crystal oscillator is stable. Once the digital reset is released, the digital core wakes up and enters the INIT_RC state. Once the configuration stored in AON and OTP is restored to the configuration register, the device enters the IDLE_RC state. At this point the host can set the AINIT2IDLE configuration bit in SEQ_CTRL, the IC will enable the CLKPLL and wait for it to lock before entering the IDLE_PLL state. When external power is first supplied to the DW3000 chip (cold start), the internal power-on reset (POR) circuit compares the external supply voltage (VDD1) with the internal power-on threshold (approximately 1.5V), once this threshold is exceeded, the external device enable pin EXTON is pulled high. The VDD2a and VDD3 supplies are monitored, and once they exceed the specified required voltages, the fast RC oscillator (FAST_RC) and crystal oscillator (XTALOscillator) will start within 500ms and 1ms.

[0050] Embodiment 3

[0051] In this embodiment, the working principle of the present invention will be introduced.

[0052] The DW3000 chip works with the antenna matching, optimizing transmission through the RF matching circuit, and the reflection coefficient is:

[0053]

[0054] Among them, Z L is the load impedance (antenna impedance), and Z0 is the characteristic impedance of the transmission line. In UWB communication, the path loss of the transmission signal will affect the signal strength and positioning accuracy. The calculation formula of path loss is:

[0055] L = 10nlog 10 (d)+A

[0056] Where L is the path loss (dB), n is the environmental attenuation factor, d is the distance from the base station to the UWB device (m), and A is a constant under environmental conditions.

[0057] Increasing the gain of the antenna concentrates energy in a specific direction, thereby increasing the signal strength in that direction and extending the effective communication distance. When transmitting signals, high-gain antennas can reduce signal attenuation, improve reception quality and signal anti-interference capabilities. The formula for calculating gain is as follows:

[0058]

[0059] Among them, G(θ,φ) is the gain of the antenna in directions θ and φ, Radiated Power in Direction(θ,φ) is the radiated power of the antenna in a certain direction, and Total Radiated Power is the total radiated power of the antenna. The gain of an omnidirectional antenna is radiated evenly on a plane, and its maximum gain is roughly the same in each direction.

[0060] The radiation pattern of an omnidirectional antenna is scanned 360°, and an ideal omnidirectional antenna provides uniform radiation along the horizontal axis of the antenna. For UWB omnidirectional antennas, the change in radiation pattern is frequency-dependent within the wideband (UWB) frequency range, and the shape and gain will change with frequency.

[0061] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A UWB device capable of achieving 360-degree omnidirectional positioning, characterized in that: include: A first RF coaxial connector U2, a second RF coaxial connector U4, a wireless transceiver chip and a crystal oscillator circuit; The first RF coaxial connector U2 is connected to the RF2 pin of the wireless transceiver chip through an eighteenth capacitor C18; The second RF coaxial connector U4 is connected to the RF1 pin of the wireless transceiver chip through a nineteenth capacitor C19; Two ends of the crystal oscillator circuit are respectively connected to the XTO pin and the XTI pin of the wireless transceiver chip.

2. A UWB device capable of achieving 360-degree omnidirectional positioning according to claim 1, characterized in that: The wireless transceiver chip includes: a chip body U3, a 20th capacitor C20, a 21st capacitor C21, a 22nd capacitor C22, a 23rd capacitor C23, a 24th capacitor C24, a 25th capacitor C25, a 26th capacitor C26, a 27th capacitor C27, a 28th capacitor C28, a 29th capacitor C29 and a magnetic bead U6; The 20th capacitor C20 is a decoupling capacitor, one end of the 20th capacitor is connected to the VIO_D pin of the chip body U3, and the other end is grounded; one end of the 21st capacitor C21 is connected to the VTX_D pin of the chip body U3, and the other end is grounded; one end of the 28th capacitor C28 is connected to the VDD1 pin of the chip body U3, and the other end is grounded; one end of the 29th capacitor C29 is connected to the VDD2a pin of the chip body U3, and the other end is grounded; The magnetic bead U6 is configured on the power line of the VDD2a pin, one end of the magnetic bead U6 is connected to the 3.3V power supply, and the other end is connected in parallel with the twenty-ninth capacitor C29 and then connected to the VDD2a pin of the chip body U3; One ends of the 22nd capacitor C22, the 23rd capacitor C23 and the 24th capacitor C24 are connected in parallel to the VDD3 pin of the chip body U3 and the 3.3V power supply, and the other ends are connected in parallel to the ground; One ends of the 25th capacitor C25, the 26th capacitor C26 and the 27th capacitor C27 are connected in parallel to the VDD2b pin of the chip body U3 and the 3.3V power supply, and the other ends are connected in parallel to the ground.

3. A UWB device capable of achieving 360-degree omnidirectional positioning according to claim 2, characterized in that: The crystal oscillator circuit comprises: a first crystal oscillator U7, a 30th capacitor C30 and a 31st capacitor C31; The first pin of the first crystal oscillator U7 is grounded through the 30th capacitor C30, and is also connected to the XTO pin of the chip body U3; The third pin of the first crystal oscillator U7 is grounded through the thirty-first capacitor C31, and is also connected to the XTI pin of the chip body U3; The second pin and the fourth pin of the first crystal oscillator are directly grounded.

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