Show HN: Ultrasonic 3D motion capture (Orientator) A developer has created Orientator, an ultrasonic 3D motion capture system using three transducers and microphones for 6DOF tracking at low cost and computational load. The device achieves ±1 mm spatial accuracy and ±1° angle accuracy within a 700 mm range at 13 FPS, with potential applications in VR controllers and plant construction alignment. Future plans include extending range to 2000 mm, improving frame rate, and reducing costs via MEMS technology. 6DOF tracking at extremely simple and cheap The computational load is light It can be used in places where light cannot be used How about using it as a VR controller ? Alternatively, it can be used, for example, to measure spatial displacement or alignment of piping during plant construction. We achieved spatial measurement by using 3 ultrasonic transducers and 3 ultrasonic microphones. The measurement principle is based on 3 sets of 3-side measurements. We acquire plane equations of microphones and transducers, and calculate the orientation angle and direction based on the surface normal vector. Current specifications are as follows: Table 1 Examination result and performance of apparatus Performance Item | Value | | Spatial dimension measurement range | About 1000 mm | | Motion capture operating range | About 700 mm | | Spatial dimensional accuracy | About ±1 mm | | Measurement angle accuracy | About ±1 ° | | Frame per Second FPS | About 13 FPS | | Mismeasurement rate MAX. | 5 FPS | Depends on the device's speed, position, direction, and orientation. < Future Challenges and Prospects --Extending the measurable distance range for spatial dimension measurement In Table 1, the measurable range is approximately 1000mm, but over 2000mm is desired for plant sites. To extend the range while maintaining accuracy, it is necessary to improve the S/N ratio by increasing transmitter output, enhancing receiver sensitivity, and optimizing cross-correlation methods for the transmitted and received waveforms. Optimization of the number of integrations for reception data is also required. --Improving performance for motion capture As shown in Table 1, motion capture performance features a range of 700mm at 13 FPS, with errors in convergence calculations at a maximum of 5 FPS. To enhance work safety by monitoring during pipe movement, increasing the frame rate and decreasing convergence errors are necessary. This includes investigating transmission waveforms that are easier to identify 9 and improving the numerical calculation routines for Newton's method to ensure more reliable convergence. --Supplying the device at a lower cost Compared to optical motion capture, this ultrasonic device has fewer parts and lower computational loads for 3D drawing and iterative calculations. To supply it more cheaply, we plan to replace general-purpose FPGA boards with dedicated circuits, minimize part counts, and implement MEMS technology for transmitters, as receivers already use MEMS microphones.