Flexible and expandable 6x4 off-road UGV, with expansion rails and ESP32 slave computer, 6 wheel 4WD mobile robot chassis. The UGV02 series is a 6-wheel x 4WD mobile robot chassis that offers excellent off-road capability and shock absorption. It supports multiple host computers (Raspberry Pi, Jetson Nano, Jetson Orin Nano etc.) and allows communication with the ESP32 slave computer via the serial interface. The 6 wheel x 4WD design increases ground contact surface and load capacity and provides powerful performance. It has a built-in 3S UPS power module that enables uninterrupted operation and supports simultaneous charging and power delivery. In addition, it offers an integrated multi-functional robot driver board based on the ESP32 with integrated WLAN and Bluetooth.