Six-rotor unmanned aerial vehicle-mounted 77GHz millimeter wave radar imaging device with holder

Abstract

Due to the fact that the space and the loading capacity of a quadrotor unmanned aerial vehicle platform are limited and a radar and the unmanned aerial vehicle are installed in a hard connection mode, attitude changes and motion errors of the unmanned aerial vehicle platform can be directly transmitted to the radar, radar beams have large deviation and shaking in the imaging working process, motion error compensation is difficult, and the imaging efficiency is high. Therefore, the SAR image quality is reduced. Therefore, the utility model provides a six-rotor unmanned aerial vehicle-mounted 77GHz millimeter wave radar imaging device with a three-axis servo stability augmentation holder, which comprises a six-rotor unmanned aerial vehicle, a 77GHz millimeter wave radar and the three-axis servo stability augmentation holder. As the unmanned aerial vehicle platform and the millimeter-wave radar are connected and installed through the three-axis servo stability augmentation holder, the influence of the attitude change and the motion error of the six-rotor unmanned aerial vehicle platform on the millimeter-wave radar can be effectively reduced, the stability of the beam pointing of the millimeter-wave radar in the imaging process is ensured, and the purpose of improving the SAR imaging quality is further achieved.

Description

Technical Field

[0001] The present invention belongs to the field of radar imaging technology, and in particular relates to a 77GHz millimeter-wave radar imaging device carried by a six-rotor unmanned aerial vehicle with a gimbal. Background Art

[0002] 77GHz millimeter-wave radar, due to its high operating frequency, wide signal bandwidth, and frequency-modulated continuous wave (FMCW) technology, offers advantages such as low cost, light weight, low power consumption, and high spatial resolution. Compared to traditional optoelectronic and infrared devices, millimeter-wave radar is less affected by weather conditions such as rain, fog, dust, and haze. It offers all-day, all-weather detection capabilities and a long range, making it a core sensor in Advanced Driver Assistance Systems (ADAS).

[0003] Existing 77GHz millimeter-wave radar imaging systems are implemented on quadrotor drones. These systems are low-cost, simple in structure, easy to operate, and portable, enabling them to acquire high-resolution SAR images of targets within their detection area at low altitudes. However, due to the limited space and payload capacity of quadrotor drone platforms, the 77GHz millimeter-wave radar and the drone platform are hard-wired. Consequently, any attitude changes and motion errors of the drone platform are directly transmitted to the radar, causing significant deviation and shaking of the radar beam during imaging. This makes it difficult to compensate for the millimeter-wave radar's motion errors, resulting in reduced SAR image quality. Summary of the Invention

[0004] To address the existing issue of quadrotor drone platform attitude changes and motion errors directly transmitting to the millimeter-wave radar, this utility model proposes a hexacopter drone-mounted 77GHz millimeter-wave radar imaging device with a three-axis servo-stabilized gimbal. The device comprises a hexacopter drone, a 77GHz millimeter-wave radar, and a three-axis servo-stabilized gimbal. Because the drone platform and the millimeter-wave radar are connected via the three-axis servo-stabilized gimbal, the impact of the hexacopter platform's attitude changes and motion errors on the millimeter-wave radar is effectively reduced, ensuring the stability of the millimeter-wave radar beam pointing during imaging, thereby improving SAR imaging quality.

[0005] The utility model discloses a 77GHz millimeter-wave radar imaging device mounted on a hexacopter drone, comprising a 77GHz millimeter-wave radar, a three-axis servo-stabilized gimbal, and the hexacopter drone. The 77GHz millimeter-wave radar is composed of four cascaded millimeter-wave radar chips, with a total of 12 transmit channels and 16 receive channels, for transmitting, receiving, and storing radar data during the millimeter-wave radar imaging process. The three-axis servo-stabilized gimbal comprises three encoder brushless motors, which respectively implement 360-degree rotation control in yaw, roll, and pitch. The hexacopter drone includes six propeller-containing arms, a power management module, a high-precision positioning module, and a wireless network port data transmission module, which provide DC12V power, high-precision positioning, and data transmission for the 77GHz millimeter-wave radar. The 77GHz millimeter-wave radar is connected to the bottom of the hexacopter drone via the three-axis servo-stabilized gimbal, which reduces vibration and stabilizes the 77GHz millimeter-wave radar imaging, effectively compensating for the effects of mechanical vibration and attitude changes in yaw, roll, and pitch of the hexacopter drone.

[0006] Furthermore, the 77GHz millimeter wave radar operates at a frequency of 76GHz to 81GHz, has a working bandwidth of 5GHz, a sampling rate of 2MHz, 512 range sampling points, a frequency modulation period of 400us, a signal bandwidth of 500MHz, and uses 9 linearly evenly distributed transmitting units for transmit beam synthesis. The receive beam synthesis uses 8 linearly evenly distributed receiving units. The signal system used is frequency modulated continuous wave, the operating voltage is DC12v, the average power is about 15W, the maximum power is less than 30W, the whole machine weighs 200g, and the radar size is 160mm long x 136mm wide x 50mm thick.

[0007] Furthermore, the wheelbase between two propellers on the diagonal line of the six-rotor drone is 1260mm, the unfolded dimensions are 1950mm long x 1950mm wide x 600mm high, the whole machine weighs 13kg, the additional mounted payload weight is not less than 10kg, the horizontal positioning accuracy is better than 10cm, and the data transmission rate is not less than 20Mbps.

[0008] Furthermore, the three-axis servo-stabilized gimbal has a front dimension of 220mm high x 215mm long, a side dimension of 220mm high x 150mm wide, and weighs 1.5kg. It can achieve 360-degree rotation control in yaw, roll, and pitch, with a maximum control speed of 360 degrees / s and an angular jitter of less than 0.02 degrees.

[0009] Furthermore, it also includes a square frame support frame to ensure the safety of the aircraft during take-off and landing.

[0010] The beneficial effects of the present invention are

[0011] By adding a three-axis servo stabilization gimbal to the 77GHz millimeter-wave radar, the utility model effectively eliminates the radar beam shaking problem caused by the rotor UAV platform itself and external environmental factors. Compared with the case without a three-axis servo stabilization gimbal, it can obtain long-term stable SAR images, which has important application value in the fields of geographic surveying and mapping, disaster assessment, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a physical picture of the six-rotor drone imaging device based on 77GHz millimeter wave radar.

[0013] Figure 2 Schematic diagram of 77GHz millimeter wave radar.

[0014] Figure 3 Schematic diagram of a six-rotor drone.

[0015] Figure 4 Schematic diagram of the front and side of the three-axis servo stabilized gimbal.

[0016] Figure 5(a) is an optical diagram of the imaging scene.

[0017] Figure 5(b) shows the imaging results of the 77GHz millimeter-wave radar on a quadrotor drone in a gimbaled state.

[0018] Figure 5(c) shows the imaging results of a 77GHz millimeter-wave radar mounted on a six-rotor drone with a gimbal.

[0019] Figure 6 This is a physical picture of the square frame support frame.

[0020] Among them, 1-77GHz millimeter wave radar; 2-three-axis servo stabilized gimbal; 3-six-rotor drone platform. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] As attached Figure 1 As shown, this embodiment provides a 77GHz millimeter-wave radar imaging device mounted on a six-rotor drone with a gimbal, including a 77GHz millimeter-wave radar 1, a three-axis servo-stabilized gimbal 2, and a six-rotor drone 3.

[0023] The 77GHz millimeter-wave radar 1 consists of four cascaded AWR2243 77GHz millimeter-wave radar chips, with a total of 12 transmit channels and 16 receive channels, which are used to transmit, receive and store radar data during the millimeter-wave radar imaging process.

[0024] The three-axis servo-stabilized gimbal 2 consists of three encoded brushless motors, which can achieve 360-degree rotation control in three axes (yaw, roll, and pitch). It is used for connecting and installing 77GHz millimeter-wave radars and UAV platforms. It adopts an integrated shock absorption and stabilization design, which can effectively compensate for mechanical vibrations and three-axis attitude changes caused by the rotor UAV platform itself and external factors.

[0025] The six-rotor drone platform 3 consists of six arms with propellers. It contains a power management module, a high-precision positioning module, and a wireless network port data transmission module, which are used to provide a stable DC12V power supply, high-precision positioning, and network port data transmission capabilities for the 77GHz millimeter wave radar.

[0026] As attached Figure 2 The figure shows the physical image of the 77GHz millimeter-wave radar TIDEP-01012 of this embodiment. In this embodiment, the operating parameters of the TIDEP-01012 millimeter-wave radar are as follows: the operating frequency band is 77GHz, the sampling rate is 2MHz, the number of range sampling points is 512, the frequency modulation period is 400us, the signal bandwidth is 500MHz, the transmit beamforming uses 9 linearly evenly distributed transmit units, and the receive beamforming uses 8 linearly evenly distributed receive units. The TIDEP-01012 millimeter-wave radar is composed of four 77GHz millimeter-wave radar chips, the chip model is AWR2243, with an operating frequency of 76GHz to 81GHz and an operating bandwidth of 5GHz. The single-chip AWR2243 chip integrates three transmit channels and four receive channels, and is a general-purpose chip-based millimeter-wave radar mass production with low cost. The TIDEP-01012 millimeter-wave radar has 12 transmit channels and 16 receive channels, supporting beamforming (BF) for medium- and long-range radars and MIMO (Multiple Input Multiple Output) for short-range radars. The radar uses a frequency modulated continuous wave (FMCW) signal system, operates at a DC12V voltage, has an average power of approximately 15W, and a maximum power of less than 30W. The radar weighs approximately 200g and measures 160mm (length) x 136mm (width) x 50mm (thickness). This low-power, lightweight, and compact device is well-suited for use on rotary-wing UAV platforms.

[0027] like Figure 3 The following diagram shows the design of the hexacopter platform in this embodiment. In this example, the KP1260X6, a long-endurance hexacopter drone from Kunshan Kunpeng UAV Technology Co., Ltd., is used. The operating parameters of the hexacopter's millimeter-wave radar are as follows: a flight altitude of 60 meters and a flight speed of 6 meters per second.

[0028] The KP1260X6 hexacopter drone platform consists of six propeller arms, with a wheelbase of 1260mm between diagonal propellers. The platform's dimensions (including propellers and landing gear) when unfolded are 1950mm (length) x 1950mm (width) x 600mm (height), weighing 13kg. It can carry an additional payload of at least 10kg. The drone platform uses two 6S high-voltage lithium-ion batteries, each weighing 3kg and having a capacity of 3000mAh. The onboard power management module provides a stable DC12V power supply for the 77GHz millimeter-wave radar. The drone is also equipped with a high-precision RTK module and a wireless network data transmission module, offering horizontal positioning accuracy better than 10cm and a transmission rate of at least 20Mbps. This provides high-precision positioning and network data transmission for the 77GHz millimeter-wave radar, making it a suitable carrier for the TIDEP-01012 millimeter-wave radar.

[0029] During the actual imaging flight, the landing legs of the UAV platform have a certain shielding effect on the radar beam and need to be removed in advance. Therefore, we built a square frame support frame for the UAV platform to ensure the operational safety of the aircraft during takeoff and landing. Figure 6 shown.

[0030] As attached Figure 4 The following diagram shows the design of the three-axis servo-stabilized gimbal in this embodiment. This embodiment is designed based on the specific dimensions and weight of the TIDEP-01012 millimeter-wave radar. Specific parameters are as follows: front dimensions are 220mm (height) x 215mm (length), side dimensions are 220mm (height) x 150mm (width), and it weighs 1.5kg. It can achieve 360-degree rotation control in each of the three axes (yaw, roll, and pitch), with a maximum control speed of 360 degrees / s and angular jitter less than 0.02 degrees.

[0031] This gimbal uses a brushless encoder motor to precisely control the angle of the TIDEP-01012 millimeter-wave radar. It includes an encoder plate that enables 360-degree rotation control along each of the three axes (yaw, roll, and pitch), with a maximum control speed of 360 degrees per second and angular jitter less than 0.02 degrees. The gimbal's integrated vibration reduction and stabilization design effectively compensates for mechanical vibration and three-axis attitude changes caused by the rotorcraft platform itself and external factors. This effectively improves the TIDEP-01012 millimeter-wave radar's beam stability during imaging, enhancing SAR image quality.

[0032] FIG5 shows a comparison of 77GHz millimeter-wave radar imaging results and optical images of the imaging scene using a gimbal in this embodiment. FIG5(a) shows an optical image of the SAR imaging scene, FIG5(b) shows the imaging result of a 77GHz millimeter-wave radar mounted on a quadrotor drone without a gimbal, and FIG5(c) shows the imaging result of a 77GHz millimeter-wave radar mounted on a hexacopter drone with a gimbal. The comparison reveals that, without a three-axis servo-stabilized gimbal, the quadrotor drone's platform vibration, attitude tilt, and external environmental factors are directly transmitted to the 77GHz millimeter-wave radar, causing significant vibration of the radar beam during flight imaging, particularly back-and-forth oscillation in the pitch direction. This is reflected in the SAR imaging results as numerous light and dark fringes of varying widths along the azimuth, severely impacting SAR image quality. The 77GHz millimeter-wave radar imaging device mounted on a hexacopter drone with a gimbal, proposed in this utility model, addresses this issue, effectively suppressing light and dark fringes in SAR images and significantly improving SAR image quality.

[0033] The present invention is not limited to the above specific embodiments, and various modifications and variations are possible. Any modification, equivalent replacement, improvement, etc. made to the above embodiments based on the technical essence of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A 77GHz millimeter-wave radar imaging device mounted on a six-rotor drone with a gimbal, characterized by: Including 77GHz millimeter wave radar, three-axis servo stabilization gimbal and six-rotor drone; The 77GHz millimeter-wave radar is composed of four cascaded millimeter-wave radar chips, with a total of 12 transmit channels and 16 receive channels, which are used to transmit, receive and store radar data during the millimeter-wave radar imaging process; The three-axis servo stabilization gimbal is composed of three encoder brushless motors, which can realize 360-degree rotation control in yaw, roll and pitch respectively. The six-rotor drone includes six arms with propellers, a power management module, a high-precision positioning module, and a wireless network port data transmission module, which are used to provide DC12V power supply, high-precision positioning, and data transmission functions for the 77GHz millimeter wave radar; The 77GHz millimeter-wave radar is connected to the bottom of the six-rotor drone via a three-axis servo-stabilized gimbal. The three-axis servo-stabilized gimbal achieves vibration reduction and stabilization for the 77GHz millimeter-wave radar imaging, effectively compensating for the effects of the six-rotor drone's mechanical vibration and changes in its yaw, roll, and pitch three-axis attitude.

2. The 77 GHz millimeter wave radar imaging device mounted on a six-rotor drone with a gimbal according to claim 1, characterized in that: The 77GHz millimeter-wave radar operates at a frequency of 76GHz to 81GHz, has a working bandwidth of 5GHz, a sampling rate of 2MHz, 512 range sampling points, a frequency modulation period of 400us, a signal bandwidth of 500MHz, and uses 9 linearly evenly distributed transmitting units for transmit beamforming and 8 linearly evenly distributed receiving units for receive beamforming.

3. The 77 GHz millimeter wave radar imaging device mounted on a six-rotor drone with a gimbal according to claim 2, characterized in that: The 77GHz millimeter-wave radar uses a frequency-modulated continuous wave signal system, an operating voltage of DC12v, an average power of approximately 15W, a maximum power of less than 30W, a total weight of 200g, and a radar size of 160mm long x 136mm wide x 50mm thick.

4. The 77 GHz millimeter wave radar imaging device mounted on a hexacopter drone with a gimbal according to claim 1, characterized in that: The wheelbase between two propellers on the diagonal line of the six-rotor drone is 1260mm, the unfolded dimensions are 1950mm long x 1950mm wide x 600mm high, the whole machine weighs 13kg, and the weight of the additional mounted payload is not less than 10kg.

5. The 77 GHz millimeter wave radar imaging device mounted on a six-rotor drone with a gimbal according to claim 4, characterized in that: The six-rotor drone has a horizontal positioning accuracy better than 10 cm and a data transmission rate of no less than 20 Mbps.

6. The 77 GHz millimeter wave radar imaging device mounted on a six-rotor drone with a gimbal according to claim 1, characterized in that: The three-axis servo-stabilized gimbal has a front dimension of 220mm high x 215mm long, a side dimension of 220mm high x 150mm wide, and weighs 1.5kg. It can achieve 360-degree rotation control in yaw, roll, and pitch, with a maximum control speed of 360 degrees / s and an angular jitter of less than 0.02 degrees.

7. The 77 GHz millimeter wave radar imaging device mounted on a six-rotor drone with a gimbal according to claim 1, characterized in that: It also includes a square frame support frame to ensure the safety of the aircraft during takeoff and landing.

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