Smart Elevator: Radar based elevator door controller

[Infineon_Team]

This is a demo project on how we can use Infineon’s XENSIV™ 60 GHz BGT60LTR11AIP radar sensor to make the Elevator smarter by controlling the doors based on human presence and direction of movement detection. Additionally, radar has a huge advantage over PIR sensors as it detects the direction of movement so that it only opens the door whenever necessary. This demo application showcases how one can use BGT60LTR11AIP shield with PSoC™ 6 MCU to realize this use case.

XENSIV™ BGT60LTR11AIP is a 60GHz Doppler-based radar sensors with one transmitting and one receiving antenna. It is the smallest motion sensor in the market, featuring integrated antennas as well as integrated detectors for motion as well as the direction of motion detection. The device supports multiple operating modes including a fully autonomous mode that does not require any software or hardware design which enables integrating this radar sensor into the elevator really easy!

The idea here is, the radar detects the presence of person and the direction of movement of that person and based on that, the elevator operates its doors. Exploring the different use cases one can,

• Avoid the door closing while you are approaching the elevator
• Trigger a door open when elevator is at idle
• Call the elevator to the current floor
• And many more such applications

Project Setup:

Figure 1: Radar sensor placement

Figure 2: Connection setup

Pin connections:

BGT60LTR11AIP	PSoC™ 6
TD	P11_4
PD	P12_3
VCC	3.3V
GND	GND
Door closing status	P9_7
Door closed status	P9_6
Toggle door open	P11_2

Note: P11_2 can be connected to anything based on the requirement, it can be connected to a servo to press the door open button or can be integrated into the lift wiring harness to short the door close button etc. All the pin connections and status flags functions are commented in the main.c file.

Project Description:

Before everything let’s know what TD and PD pins are. TD pin refers to Target Detect and this pin will go LOW when a target is detected and HIGH when no target is detected. And, PD pin refers to Phase Detect, this pin will go HIGH when approaching target is detected and goes LOW when departing target is detected.

Speaking about working of this application,

1. While the doors are closing: While the doors are closing, we read the Target detect (TD) and Phase detect (PD) pins. When the target is detected and is approaching during door closing event, the application toggles and GPIO pin. User can read status of this GPIO pin (P11_2) to trigger door open (<>) button of the elevator.
2. While the doors are closed: While doors are closed, we read the Target detect (TD) and Phase detect (PD) pins to detect if a target is present and is approaching and, in this case, we open the doors by the toggling a GPIO pin. User can read status of this GPIO pin (P11_2) to trigger door open (<>) button of the elevator.

Code flow:

Project Execution

Case 1: The doors automatically open when person approaches the elevator.

Case 2: When the doors are closing and a person approaches, the doors reopen.

Case 3: The doors do not open when a person is moving Sideways.

Case 4: The doors do not open when a person is moving away from elevator.