Page is loading ...
LD-24 24GHz Millimeter-Wave
Radar Manual
Table of Contents
1. Product Overview ..................................................................................................... 1
2. Product Technical Parameters .................................................................................. 1
2.1 System Features ...........................................................................................1
2.2 Ranging Feature ........................................................................................... 2
2.3 Antenna Characteristics ............................................................................... 2
2.4 Product Pin Definition ...................................................................................2
2.5 Data Interface Protocol ................................................................................ 3
3.Joint Test of Ground Station....................................................................................... 3
3.1 Overall Functional Description ..................................................................... 5
3.2 Operating Environment ............................................................................... 5
4. Cautions ....................................................................................................................7
4.1 Transport , Storage and Use Precautions.......................................................7
4.2 Shell Design Parameters and Installation Requirements .............................. 8
5. Application Scenario .................................................................................................8
Disclaimer:
Please read the contents of this manual carefully to ensure that you can
use this product correctly and safely. Once used, it is deemed to be an
acknowledgement and acceptance of the contents of this statement. Please
strictly follow the manual to install and use this product . If there is
any damage or damage caused by incorrect use, Foxtech will not be
responsible for the corresponding loss and compensation. In line with the
principle of continuous improvement and continuous development, the
company reserves the right to modify and improve any product details
described in the document without prior notice. The content in this manual
is provided as of the time of manufacture, and unless otherwise required
by applicable law , no warranty of any kind, express or implied, is made
as to the accuracy, reliability, and content of this document. TO THE
MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT WILL THE COMPANY
AND ITS SUPPLIERS BE LIABLE FOR ANY SPECIAL, INCIDENTAL, INCIDENTAL , OR
CONSEQUENTIAL DAMAGES, HOWEVER CAUSED. This product is copyrighted by
Foxtech. Reproduction in any form is not permitted without permission. This
manual contains important information, please keep it for future reference.
1. Product Overview
LD-24 is a compact 24GHz millimeter-wave radar altimeter specially
designed for NAGA series multirotor. The size of the PCBA is only 45*45mm
and the weight is 6.5g.
We adopts unique antenna design, through high efficient signal
processing algorithm and high sensitive real-time signal processing method
based on time domain, frequency domain and phase, which can greatly reduce
the physical size of radar module and facilitate the integration of radar
module into the UAV fuselage, thus satisfying height determination demands
required by UAV.
The millimeter-wave radar can achieve accurate altitude measurement in
the height range of 0.2~50m (long time hovering is not recommended below
0.5m), which provides great convenience for UAV hovering and
terrain-following flight.
2. Product Technical Parameters
2.1 System Characteristics
Transmission Frequency：24.0 ~24.25GHz
Transmit Power (EIRP)：20dBm
Modulation Mode：FMCW
Hardware interface: UART-TTL
Size: 45*45*6mm （PCBA ）
Weight: 6.5g
Working voltage: 4~5.5V；Typical value: 5V ( independent power supply )
2.2 Ranging Characteristics
Distance Range：0.2m ~50m（over the ground
Working Current: 200~275mA； Typical Value: 220mA@5V
Storage Temperature: -40~85 ℃
Working Temperature: -40~80 ℃
）
Refresh Rate：50Hz
2.3 Antenna characteristics
Transmitting antenna
Elevation beamwidth：20°
Azimuth beamwidth：31°
Sidelobe Level: -19dB
Receiving antenna
Elevation beamwidth：31°
Azimuth beamwidth：20°
Sidelobe Level: -19dB
2.4 Product Pin Definition
Figure 1Product Pin Diagram
Table 1Pin Definition
Pin Definition Describe
1 VCC The Pin of positive
pole 3.5~5.5V
2 RX Data Receiving Pin
3 TX Data Sending
4 NC NA
5 NC NA
6 GND Negative Pole
Figure 2Dimensions ( unit: mm )
2.5 Data Interface Protocol
The radar adopts UART-TTL interface, using the preset default
transmission rate of 115200 bit/s , the start of the frame is indicated by the
space character of ASCII value for each datagram ( hexadecimal 0X2 0 )，at
the same time, the end of the frame is indicated by a line feed and carriage
return in the ASCII code value. LD24 radar sensor data frame refresh rate is
50Hz .
The radar uses an inquiry communication method. When the controller sends
an inquiry command once, the radar returns the current distance information
once. The query command sent by the controller is shown in Table 1.
Table 1: Controller Command List
Comment
'd' or 'D' Query the distance
information of the
radar
A complete data frame of UART-TTL communication has 7-8 bytes
according to the current measured distance of the radar. If the measured
distance is greater than 10m , use 5bytes to represent the distance information,
if it is less than 10m , use 4bytes to represent the distance information .
The data of each byte is character type, and the data frame is shown in Table
2below.
Table 2: Data Frame Format
Bytes Comment
1Frame header (frame header space)
4or 5 Distance Data
2Frame Tail
The starting sequence Frame header is a fixed value：0X20< space > , and
the ending sequence Frame Tail is a fixed value：
OX0D<CR> OX0A<LF> . An example of data analysis is shown in Table 3 :
= 0X0D 0X0A---------- <CR><LF>Frame Tail：
= 0X31 0X32 0X2E 0X33 0X34--------- 12.34Distance Data
= 0X20---------- <Space>Frame header
Eg 1：0X20 0X31 0X32 0X2E 0X33 0X34 0X0D 0X0A
Target Info Data Frame：
0X20 0X31 0X32 0X2E 0X33 0X34 0X0D 0X0A or 0X20 0X31 0X2E 0X33 0X34 0X0D 0X0A
两种情况下的数据解析：
Table 3: Data Parsing Example
The analysis is as follows:
Indicates that the distance information returned by the current radar sensor is
12.34m
Example 2 :0X20 0X31 0X2E 0X33 0X34 0X0D 0X0A
Frame header = 0X20 ---------< space >
Distance Data = 0X31 0X2E 0X33 0X34 -------- 1.34
Frame Tail :
The analysis is
as follows:
= 0X0D 0X0A -------- <CR><LF>
Indicates that the distance information returned by the current radar sensor is 1.34m
3. Joint Test of Ground Station
3.1 Overall Functional Description
The altimeter radar can display data in conjunction with the ground
station, which helps customers to more accurately debug and test the radar .
3.2 Operating Environment
The operation of 1.3.74 Mission planner software requires the
following software and hardware environments as shown in Table 4 :
Table 4Software and Hardware Environment Requirements
Category Low-end Configuration
Hardware
Requirements
CPU : 1.8GHz ; Memory: 512M ; Hard Disk: 40G
USB -to-serial cable (Note: Please make sure that the length
of the cable does not exceed 2m when upgrading the firmware )
Operating
System
support Windows 7 8 10 32 bit/64 bit
Test method is as follow: download and install the latest ground station
software from Ardupilot Website ( eg 1.3.74 Mision planner ).
https://firmware.ardupilot.org/Tools/MissionP lanner/
The testing tools or software are as follow:
LD-24 Radar
Notebook/PC
Independent Power Supply ( 5V power supply)
Mission Planner Software
Open Source Flight Controller ( if the firmware is missing, you can
download it from the Ardupilot website)
USB Cable / Datalink
LD-24 radar is connected to the open source flight control and power
input(the radar module should not be powered directly by the flight
control power supply, please ensure that it is powered by an independent
power supply), open the ground station Mission planner software and
connect to flight controller ( USB cable / datalink ). The software
operation steps are as follows: " Configuration / Debug " - " All Parameter
List "- configure the following parameters:
EK2_ALT_SOURCE=1
RNGFND1_TYPE=8
RNGFND1_ORIENT=25
SER1_BAUD=115200 (other SER ports can also be selected)
SER1_PROTOCOL=9
After configuration,operate as follow:
Click "Flight Data "to return to the main interface
Double-click the red box in Figure 3 to pop up the "Display This" interface
shown in Figure 3, and cancel other options, only check "sonarrange" ,
“sonar range”will be displayed here , which is the actual height of
the radar.
Figure 3
Figure 4
4. Cautions
4.1 Shipping, Storage and Use Precautions
It is necessary to fully do a good job of electrostatic protection during
the process of radar transportation, storage, working. When dealing with
non-integrated independent modules, users must pay attention: when the module
is taken out of the sealed anti-electrostatic package, it is necessary to
start the electrostatic protection work; do not touch or grab the surface of
the radar antenna and the connector pins, only touch its corners. It is
recommended to wear anti-electrostatic gloves whenever possible when handling all
radar sensors.
Do not wrap antennas with foil or partial metal parts; do not use CFK
sheet (conductive ) wrapping the antenna;
Do not spray the antenna structure with any kind of paint or varnish;
Do not let the plastic material come into direct contact with the antenna
structure ( which has the effect of a higher dielectric constant on
the resonant frequency of the patch ).
When the radar is installed, it is necessary to ensure that the module
is vertically downward, so as to ensure the accuracy of the detection
data.
When the radar is installed, the radar should be kept away from
electromagnetic interference sources such as motors and suspended metal
shells.
4.2 Shell design parameters and installation requirements
The radar shell will have a great influence on the actual effect of
the radar, which mainly depends on the shell material, thickness and the
distance between the inner surface of the radar module. LD-24 radar is
equipped with a wear-resistant, firm and beautiful shell structure. If you
need to customize the shell, our company can provide relevant consultation.
5. Application scenarios
The fixed altitude mode is the most important mode in the UAV flight
control, and the high-precision altimeter radar is the basis for the stable
flight of the fixed altitude mode. As we all know, fine-tuning the throttle
to ensure the lift and weight balance of the drone consumes a lot of energy for
the pilot, and the fixed altitude mode of the drone realized by the altimeter
radar can greatly reduce the difficulty of the pilot's operation. After the drone
enters the fixed altitude mode, the pilot can only control the flight direction
of the drone , which can greatly liberate the pilot and reduce the risk of
bombing. In addition, with the help of altimeter radar to achieve fixed height
hovering, you can get better photo effects. Not only that, the altimeter radar
also helps to achieve stable terrain-follow flight, improving the
applicability of UAVs in specific application scenarios such as line patrol.
/