Intelligent Patrol Robot Controller

Project Overview

A robotics company developing autonomous patrol robots for warehouse and campus security needed a high-integration controller board. The PCB serves as the brain of the robot, fusing data from multiple sensors (cameras, IMU, LiDAR) and managing wireless communication for remote monitoring.

Challenge

• Multi-sensor integration: The board needed to interface with 4 MIPI CSI cameras, a 6-axis IMU, LiDAR scanner, and ultrasonic proximity sensors simultaneously, all while maintaining real-time processing throughput.
• Wireless coexistence: WiFi 5, Bluetooth 5.0, and 4G LTE modules all shared the same board, creating RF interference management challenges.
• Power efficiency: Battery-powered operation demanded careful power domain management. The robot needed 8+ hours of autonomous patrol on a single charge.
• Vibration resistance: Continuous mobile operation on various surfaces required robust solder joints and mechanical stress considerations.

Solution

• 8-layer high-integration design: Dense component placement with RK3288 on one side and all sensor interfaces on the other. Ground plane partitioning isolated analog sensor signals from digital processing and RF sections.
• RF coexistence engineering: Separate antenna keep-out zones for WiFi, BT, and LTE. Shielding cans over each wireless module with dedicated filtered power supplies. Achieved -70dB isolation between wireless subsystems.
• Power management: 6 independent power rails with sequencing. Dynamic voltage scaling on the RK3288 reduced idle power by 40%. Careful power plane copper balancing minimized IR drop.
• Mechanical reliability: All BGA packages underfilled. Through-hole mounting for all mechanical connectors. Board-level vibration testing validated to 10G random vibration profile.

PCB Specifications

Results

• All 4 camera streams processed at 30fps simultaneously without frame drops
• Robot achieved 10-hour patrol duration, exceeding the 8-hour target
• Passed MIL-STD-810G vibration testing profile
• Successfully deployed fleet of 50+ robots across 3 pilot customer sites