Power Consumption of Robot Car with KR260

When attempting to power a KR260 robot from a battery, we experienced a power shortage during startup.

We used a commercially available PD-compatible mobile battery (20W).

Subproject for the AMD Pervasive AI Developer Contest

This project is part of a subproject for the AMD Pervasive AI Developer Contest.

Be sure to check out the other projects as well.

**The main project is currently under submission. ***

0. Main project << under submission

1. PYNQ + GPIO(LED Blinking)

2. PYNQ + PWM(DC-Motor Control)

3. Object Detection(Yolo) with DPU-PYNQ

4. Implementation DPU, GPIO, and PWM

5. Remote Control 360° Camera

6. GStreamer + OpenCV with 360°Camera

7. 360 Live Streaming + Object Detect(DPU)

8. ROS2 3D Marker from 360 Live Streaming

9. Control 360° Object Detection Robot Car

10. Imporve Object Detection Speed with YOLOX

11. Benchmark Architectures of the DPU

12. Power Consumption of 360° Object Detection Robot Car << this project

13. Application to Vitis AI ONNX Runtime Engine (VOE)

14. Appendix: Object Detection Using YOLOX with a Webcam

Please note that before running the above subprojects, the following setup, which is the reference for this AMDcontest, is required.

https://github.com/amd/Kria-RoboticsAI

Introduction

When trying to power the KR260 from a mobile battery, a power shortage occurred during the program startup.

Initially, our plan was to operate the robot equipped with the KR260 using a battery. This was because we'd like to operate the robot without being hindered by power cables.

Here is a test video showing the actual power shortage:

At the KR260 startup, there were no issues with power supply from the battery. However, it was found that the system shut down when loading the program.

When we add up the actual power consumption, it became evident that the 20W battery was insufficient. Here are the details of power consumption.

Operating KR260 with a PD20W Mobile Battery

We prepared a PD-compatible mobile battery capable of 12V output. It’s a Philips DLP7721C, with the following specs:

• Capacity: 20000mAh/3.7V

Output:

• USB-A1/A2: DC 5V/3A, 9V/2A, 12V/1.5A
• USB-C: DC 5V/3A, 9V/2.2A, 12V/1.67A

Since light mobile-batteries with outputs above 20W are quite expensive, we opted for the 20W version (as of 2024).

We also purchased a general-purpose current checker and a cable compatible with PD12V output to input 12V power into the KR260’s DC jack.

Power Consumption During Idle

The KR260 startup worked fine with the mobile battery. Linux booted normally, and during idle after plugging in the DC jack, the consumption was about 8.4W (12V_700mA).

Power Consumption with Device Connection + GUI

With a USB keyboard, mouse, and display connected, the consumption was about 10.2W (12V_850mA).

Power Consumption with 360° Camera Connection

Connecting a 360° camera resulted in a power consumption of about 12.0W (12V_1000mA).

Power Consumption During 360° Object Detection

Running the DPU for 360° object detection, the power consumption was about 16.2W (12V_1350mA).

Up to this point, the 20W mobile battery could still handle the operation.

Motor Power Consumption

The robot uses three DC motors: one for arm control and two for robot car control.

The motors use 5V power, controlled by PWM from the KR260, and were estimated at 100% operation for measurement purposes.

• Arm DC Motor: about 2.5W (5V_500mA)

• Robot Car DC Motor: about 4W each (5V_800mA)

Thus, with all motors running, the estimated power consumption was 2.5W + 4W*2 = 10.5W (though it's rare for all three to operate simultaneously).

Testing Power Deficit with KR260

Adding up the total power consumption, it reached 26.7W, exceeding the 20W capacity of the battery. Hence, the power shortage and subsequent reboot during program startup were expected.

Here is the test video mentioned earlier:

To make the reboot more noticeable, the test included a tablet (display) with the KR260 powered on and Ubuntu running.

We used a 20W (12V_1.67A) PD-compatible mobile battery and connected a USB checker to monitor the power consumption, which was displayed on the upper left screen in the video, showing voltage (V), current (A), and power (W).

The reboot occurred when the robot car program started, exceeding the 20W limit.

No Issues with the 36W AC Adapter

The 36W (12V_3A) AC adapter included in the KR260 starter kit had no issues, comfortably handling the estimated 26.7W power consumption.

Therefore, for the final robot car demonstration, We had to use the AC adapter.

The initial plan was for battery operation without cables, including motor driving and 360° object detection, but the small 20W mobile battery couldn’t suffice.

Here is the final robot car demo video.

For more information on this video, please see the following article.

9. Control 360° Object Detection Robot Car

Summary

When attempting to power a KR260 robot from a battery, we experienced a power shortage during startup.

Therefore, for the final robot car demonstration, We had to use the AC adapter included in the KR260 starter kit.

In the next project, we will also introduce the use of the Vitis AI ONNX Runtime Engine (VOE).

13. Application to Vitis AI ONNX Runtime Engine (VOE)