1
ZHCU485–April 2018
TIDUE95 — http://www-s.ti.com/sc/techlit/TIDUE95
版权 © 2018, Texas Instruments Incorporated
车辆乘员检测参考设计
TI Designs
::
TIDEP-01001
车车辆辆乘乘员员检检测测参参考考设设计计
说说明明
该参考设计演示了如何使用 AWR1642(具有集成 DSP
的单芯片毫米波传感器)作为车辆乘员检测传感器,实
现车内生命形式检测。该设计提供了一个在 C674x
DSP 上运行的参考处理链,可生成热图来检测 ±60 度
视场 (FOV) 内的生命形式。
资资源源
TIDEP-01001 设计文件夹
AWR1642 产品文件夹
AWR1642BOOST 工具文件夹
mmWaveSDK 软件开发套件
咨询我们的 E2E™ 专家
特特性性
• 演示毫米波传感器技术用于可靠检测车辆中的生命
形式(成人、儿童、宠物)。
• 生成 ±60 度 FOV 内的存在热图。
• 基于毫米波软件开发套件 (SDK) 的处理和检测源代
码
• 基于成熟的 EVM 硬件设计,可缩短上市时间并支持
开箱即用演示。
• 雷达前端和检测配置完整说明
应应用用
• 儿童遗留车内检测
• 车辆乘员检测
• 入侵者检测
该 TI 参考设计末尾的重要声明表述了授权使用、知识产权问题和其他重要的免责声明和信息。
System Description
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ZHCU485–April 2018
TIDUE95 — http://www-s.ti.com/sc/techlit/TIDUE95
版权 © 2018, Texas Instruments Incorporated
车辆乘员检测参考设计
1 System Description
Today’s vehicles require robust and reliable information about the in-cabin occupancy. Smart airbag
deployment systems, air condition controls, detecting children and disabled people left behind in vehicles
relies upon this information.
The TIDEP-01001 provides a reference for creating a vehicle occupant detection application, using TI’s
AWR1642 based on 77-GHz mmWave radio-frequency complementary metal-oxide semiconductor (RF-
CMOS) technology.
TI’s mmWave sensing devices integrate a 76-GHz to 81-GHz mmWave radar front end with ARM
®
microcontroller (MCU) and TI DSP cores for single-chip systems.
This reference design demonstrates the suitability of the AWR1642 for vehicle occupant detection
applications. This design targets the implementation of a wide, azimuth field of view (±60°), close range (3
m) sensor configuration, which can detect life forms across two regions of interest. This can be extended
to multiple regions detection.
This TI Design implements algorithms for generating an azimuth-range heat map, detection, and decision
for an AWR1642 device on a TI EVM module.
The design provides a list of required hardware, schematics, and foundational software to quickly begin
traffic monitoring product development. It describes the example usage case as well as the design
principle, implementation details, and engineering tradeoffs made in the development of this application.
High-level instructions for replicating the design are provided.
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System Overview
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TIDUE95 — http://www-s.ti.com/sc/techlit/TIDUE95
版权 © 2018, Texas Instruments Incorporated
车辆乘员检测参考设计
2 System Overview
The VOD TI design is built around the AWR1642EVM evaluation board and the millimeter wave
(mmWave) SDK demo application. The system is optimized and built for VOD applications to detect
objects within a 3-m range
2.1 Block Diagram
The mmWave software development kit (SDK) enables the development of mmWave sensor applications
using the AWR1642 SOC and EVM. The SDK provides foundational components that let end users focus
on their applications. In addition, the SDK provides several demonstration applications, which serve as a
guide for integrating the SDK into end-user mmWave applications. This TI Design is a separate package
installed on top of the SDK package.
图图 1. Software Block Diagram
2.2 Vehicle Occupancy Detection Software Block Diagram
As described in 图 2, the implementation of the vehicle occupancy detection example in the signal-
processing chain consists of the following blocks, implemented as DSP code executing on the C674x core
in the AWR1642:
• Range processing
– For each antenna, 1D windowing, and 1D fast Fourier transform (FFT).
– Range processing is interleaved with the active chirp time of the frame.
• Clutter removal
– Estimate the DC component for each range bin, across chirps in a frame.
– Subtract the estimated DC component for each range bin.
• Range-Azimuth heatmap generation
System Overview
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车辆乘员检测参考设计
– Perform Direction-of-Arrival (DOA) Spectral Estimation to calculate a 2D heatmap for the frame,
indexed by range (N
r
, rows) and azimuth (N
az
, columns).
• Feature Extraction
– Each frame, scan the heatmap within each defined zone of interest and compute a feature vector:
• Average zone power
• Moving-average zone power (for L (window length), frames)
• Moving-average power ratio (for L frames)
• Correlation coefficient of zone power
• Zone Detection
– For N
z
zones, there are 2
Nz
possible occupancy states. Offline, define a matrix of decision
parameters (coefficients) to represent targets of interest (adults, children, pets, etc).
– Perform matrix multiplication with the decision parameters and feature vector. This yields an array
of flags, one flag per zone, a 1 indicating ‘zone occupied’, and 0 indicating ‘empty’.
图图 2. Application Software Block Diagram
After the DSP finishes frame processing, the results are formatted and written in shared memory
(HSRAM) for the R4F MCU to send to the host through a UART for visualization.
2.3 Highlighted Products
2.3.1 AWR1642 Single-Chip Radar Solution
The AWR1642 is an integrated single-chip FMCW sensor capable of operation in the 76-GHz to 81-GHz
band. It is built with TI’s low power 45-nm RFCMOS process, and enables unprecedented levels of
integration in an extremely small form factor. The AWR1642 is an ideal solution for low power, self-
monitored, ultra-accurate radar systems in the automotive and industrial space.
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System Overview
5
ZHCU485–April 2018
TIDUE95 — http://www-s.ti.com/sc/techlit/TIDUE95
版权 © 2018, Texas Instruments Incorporated
车辆乘员检测参考设计
图图 3. AWR1642BOOST EVM Block Diagram
The AWR1642 EVM has the following features:
• AWR1642 radar device
• Power management circuit to provide all the required supply rails from a single 5-V input.
• Two onboard TX antennas and four RX antennas
• Onboard XDS110, which provides JTAG interface, UART1 for loading the radar configuration on the
AWR1642 device, and UART2 to send the object data back to the PC.
For more details on the hardware, see the AWR1642 Evaluation Module (AWR1642EVM) Single-Chip
mmWave Sensing Solution. The schematics and design database can be found in the following
documents: the AWR1642 Evaluation Board Design Database and the AWR1642EVM Schematic,
Assembly, and BOM .
2.3.2 mmWaveSDK
The mmWave SDK is split in two broad components: the mmWave Suite and mmWave demos. The
mmWave Suite is the foundational software part of the mmWave SDK and includes smaller components:
• Drivers
• OSAL
• mmWaveLink (BSS interface API)
• mmWaveLib (C674 optimized library)
• mmWave API (High level control API)
• BSS firmware
• Board setup and flash utilities
The mmWave SDK demos provide a suite of demonstrations that depict the various control and data
processing aspects of an mmWave application. Data visualization of the demonstration's output on a PC is
provided as part of these demonstrations:
• mmWave processing demonstration
• ADC data streaming demonstration
2.4 System Design Theory
2.4.1 Use Case Geometry and Sensor Considerations
The AWR1642 is a radar-based sensor that integrates a fast FMCW radar front end with both an
integrated ARM R4F MCU and the TI C674x DSP for advanced signal processing.
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