animate_imu • imuf

Introduction

This vignette describes how one may generate a 3-D animation of a time series of orientations of an inertial measurement unit (IMU).

We first follow the steps described in vignette("imuf") to generate a time series of orientations using the walking_shin_1 dataset:

library(imuf)
library(purrr)
#
lst_ned_in <- as.list(as.data.frame(t(walking_shin_1))) %>% unname
dt <- 1/50
#
myCompUpdate <- function(initQ, accgyr) {
  acc <- accgyr[1:3]
  gyr <- accgyr[4:6]
  gain <- 0.1
  orientation <- compUpdate(acc, gyr, dt, initQ, gain)
  orientation
}
#
orientations <- purrr::accumulate(lst_ned_in, myCompUpdate, .init = c(1, 0, 0, 0))
#
head(orientations)
#> [[1]]
#> [1] 1 0 0 0
#> 
#> [[2]]
#> [1]  0.9999657701 -0.0041990423 -0.0071175965 -0.0004080098
#> 
#> [[3]]
#> [1]  0.9998798598 -0.0078567189 -0.0133472834 -0.0006228269
#> 
#> [[4]]
#> [1]  0.9997609096 -0.0111531161 -0.0187912870 -0.0007868925
#> 
#> [[5]]
#> [1]  0.9996243467 -0.0139555857 -0.0235688255 -0.0009578893
#> 
#> [[6]]
#> [1]  0.999478521 -0.016386379 -0.027797655 -0.001209502

3-D animation of IMU orientations

Next we use the animate_imu() function to visualize a 3-D animation of the orienations.

#
# time increment for animation needs to be in milli-seconds
animate_imu(orientations, dt*1000)

3-D animation of IMU orientations within Shiny

We will now illustrate how one may display the 3-D animation in Shiny.

if (interactive()) {
  library(shiny)

  ui = pageWithSidebar(
    headerPanel("render an IMU animation example"),
    sidebarPanel(),
    mainPanel(animate_imuOutput('orientations'))
  )
  
  server = function(input, output, session) {
    output$orientations <- renderAnimate_imu(
      animate_imu(orientations, dt*1000)
    )
  }
  
  shinyApp(ui = ui, server = server)
}