top of page

Portable VR Full Body Tracking

(Currently WIP) For the PDB foundation, I decided to create a product that would further enhance the Virtual Reality (VR) experience. The product was a full-body tracking system that did not require external cameras, thus making the system portable and can be used anywhere. This will provide greater immersion in VR applications through an easy and intuitive setup. Details of my experience with the PDB foundation can be found here.

The Design

The design of the full-body tracking device takes advantage of the tracking of the upper torso already provided by most VR headsets. This led to the product being developed to only track the lower torso of the wearer in order to achieve full-body tracking, thus reducing the number of sensors needed for the device along with reducing cost. The absence of these sensors is accommodated through a kinesiology measuring technique called inverse kinematics. It's a technique that is commonly used in the study of the human range of motion and 3d animation. The full-body tracking rig uses inertial measuring units (IMU) to detect the orientation of the player's limbs. By using these IMU trackers outside camera tracking and image processing are not needed. Since these peripheral tracking systems are not required, the setup for full-body tracking can be used in any room, not being limited to rooms with a dedicated VR tracking setup. A total of 5 trackers are placed on the body to track the player's lower body. The data from these trackers relay data that are translated to quaternion coordinates that are used to control the virtual limbs of the player. The rig can be rapidly strapped on and paired to a PC running the VR application.

Value Proposition

Value Propisition.png

Business Model

GIgaabusiness%2520model_edited_edited.jpg

Sensors and Hardware

  1. Teensy MicroController: This acts as the brain of the system. It takes the data from the IMU’s potentiometers and handles serial communication to the VR body tracking program. (REPLACED with a ESP8266 for serial wifi communication)

  2. Bno080 IMU (Inertial Measurement Units): These components are the main sensors of the system. By fusing the sensor inputs of the gyroscope, accelerometer, magnetometer, the orientation of the sensor can be accurately represented as a rotation vector. The vector output is converted to a quaternion format and is used as data to represent the orientation of the limb it is attached to. For this product, the orientation of the hip, upper right leg and upper left leg are tracked with the bno080 IMU.

  3. HC - 05 Bluetooth Serial Module: A Bluetooth module used to establish serial communication between the full-body tracking device and VR application. This can communicate to standalone headset devices like the Oculus Quest or PC VR headsets and applications. (REPLACED with wifi serial communication from the ESP8266)

  4. Potentiometers: A device that varies resistance (and thus electric signals) based on the rotation of its dial. These are placed on the joint that connects the upper leg to the lower leg. The potentiometers are used to measure the angle between the upper leg and lower leg and use that data to track the lower leg’s position. This takes advantage of the 2 degrees of freedom in the lower legs range of motion (flexion and extension). By using potentiometers in place of IMU’s for the lower leg can be accurately tracked and the processing data is conserved thus reducing input lag when tracking the limbs in VR.

  5. NRF24L01 - 2.4G Wireless Transceiver Module: A wireless transceiver that establishes communication between the full-body tracking device and the desired VR device. Wireless communication is established as simply as plugging a USB device into the desired VR headset or PC. 

protolayout.png

Limb Range of Motion and Sensor Placement

​

trackers.png
3DGIGA.png

Full-Body Tracking Rig

Hip Tracker Belt: The symbol on the belt buckle derives from the demo game for the device to show off its full-body tracking capabilities. The Belt houses the hip tracker, the wireless communication modules, and the microprocessor of the device.

​

Upper and Lower Leg Tracker Leg Brace x2: Leg brace of the full-body tracking device. There is a brace for the left and right sides of the full-body tracking device. The bno080 IMU is housed in the rectangular compartment in the front of the leg brace while the angle detection potentiometer is housed on the side of the leg brace (labeled L for the left leg) and is aligned with the knee joint. The leg brace uses adjustable straps to compensate for varying body types.

​

bottom of page