OpenShoe

Open­Shoe is an open source embed­ded foot-mounted INS imple­men­ta­tion includ­ing both hard­ware and soft­ware design. A cross sec­tion of a shoe with a unit of the imple­men­ta­tion inte­grated into the sole can be seen above. To our knowl­edge, this is the only imple­men­ta­tion of its kind.

The imple­men­ta­tion has been done with the hope that it will save time, sweat, and tears for nav­i­ga­tion researchers as well as facil­i­tate the use of the tech­nol­ogy by researchers not spe­cial­ized in aided INS, e.g. in fields such as bio­med­ical engi­neer­ing, behav­ioral sci­ence, and ubiq­ui­tous com­put­ing. The value of the embed­ded imple­men­ta­tion also lies in its mod­u­lar­ity and in its small weight, bulk, and price in com­par­i­son with the typ­i­cal sensor-plus-laptop research sys­tems. These prop­er­ties alle­vi­ate the work of inte­grat­ing the foot-mounted INS in larger real­time pedes­trian nav­i­ga­tion sys­tems, and make it fea­si­ble to equip a larger num­ber of users with foot­mounted INS units for field per­for­mance tests and coop­er­a­tive nav­i­ga­tion studies.

Gen­eral fea­tures of the implementation:

1. Embed­ded ZUPT aided INS
2. Open source and fully documented
3. Repro­duc­tion cost below $800

Hard­ware features:

1. Designed for an Ana­log Devices ADIS16367 IMU but with inter­face com­pitabil­ity with all IMUs in the iSen­sor serie
2. 820[Hz] sam­pling rate, 18[g] and 1200°/s dynamic range, 330[Hz] sen­sor band­width using the ADIS16367 IMU
3. Atmel AVR32UC3C micro­con­troller with hard­ware float­ing point
4. Foot­print 28.5x32x40.5[mm]
5. USB inter­face

Soft­ware features:

1. Source code writ­ten in C
2. Eas­ily con­fig­ured to run any user imple­mented algorithms
3. Mat­lab code avail­able for communication
4. Repro­gram­ma­ble through the USB interface.
5. Appear as a vir­tual com-port
6. Con­fig­urable to work as an IMU, as a stand-alone ZUPT-aided INS, and as a dis­place­ment and head­ing change sensor.

The sys­tem is eas­ily repro­ducible. On this site you can find:

1. Pre­com­piled code
2. Fully doc­u­mented C source code
3. Pro­duc­tion files for PCB/PCA and casing

For a more detailed pre­sen­ta­tion of the imple­men­ta­tion, see the arti­cle Foot-mounted INS for Every­body — An Open-Source Embed­ded Imple­men­ta­tion (opens in a new tab).

We hope that you find the imple­men­ta­tion inter­est­ing and use­full. If you have any ques­tions, com­ments, sug­ges­tions, or enquiries, please con­tact us at openshoe@ee.kth.se.

Best regards
/The Open­Shoe team

Roughly a year after the Open­Shoe imple­men­ta­tion was pub­lished and after a hec­tic year of fur­ther devel­op­ment, we have now devel­oped a com­plete real-time multi-agent coop­er­a­tive local­iza­tion sys­tem based on the setup illus­trated in the image above. An arti­cle describ­ing the main parts of this sys­tem is avail­able at arXiv (Coop­er­a­tive local­iza­tion by dual foot-mounted iner­tial sen­sors and inter-agent rang­ing)

This work on coop­er­a­tive local­iza­tion is not really a part of the Open­Shoe project but it nat­u­rally have many con­nec­tions since the Open­Shoe units are an cru­cial com­po­nent in it. From the Open­Shoe per­spec­tive, the main result of the arti­cle is that it describes how the Open­Shoe units should be integrated/viewed from a sys­tem per­spec­tive. Also, build­ing the sys­tem has forced us update the soft­ware of the sys­tem and to imple­ment many new fea­tures. I hope that I will soon find find the time to clean up these fea­tures and merge the banches with the trunk on SourceForge.

The last pub­li­ca­tions from IPIN last Novem­ber (2012 Inter­na­tional Con­fer­ence on Indoor Posi­tion­ing and Indoor Navigation)

• Fus­ing the Infor­ma­tion from Two Nav­i­ga­tion Sys­tems Using an Upper Bound on Their Max­i­mum Spa­tial Separation
• Smooth­ing for ZUPT-aided INSs

have now been added under the pub­li­ca­tion section.

Dur­ing the third week of Jan­u­ary some of us attended the IEEE CONECCT con­fer­ence. Thereat Isaac Skog and John-Olof Nils­son gave a tuto­r­ial on pedes­trian track­ing by means of foot-mounted iner­tial sen­sors and on coop­er­a­tive local­iza­tion. Too late to attend but once we have hade time to clean out exces­sively large video-clips from the pre­sen­ta­tions we will try to upload them here.

Due to exces­sive work­load, there has been no updates on this home­page for a while. No we’re back to nor­mal lev­els so I’ll try to write some posts about what has hap­pend since the end of last year. First of all, dur­ing the sec­ond week of Jan­u­ary we joined up with our Indian col­legues for a work­shop at IISc. Below is a photo of the atten­dees of the workshop.

The work­shop con­cerned mul­ti­ple areas within the local­iza­tion research con­ducted at KTH and IISc and there­fore nat­u­raly also the Open­Shoe project, or rather pri­mar­ily the use of the Open­Shoe units. The peo­ple at IISc has recently pub­lished the paper Data Fusion of Dual Foot-Mounted INS to Reduce the Sys­tem­atic Head­ing Drift (See Pub­li­ca­tions) and we had a small bench­mark test com­par­ing the solu­tion to the sen­sor fusion solu­tions ear­lier devel­oped at KTH. Bench­mark tests going on:

Today a for­mer mas­ter the­sis stu­dent showed up at our lab with home­made Open­Shoe cas­ing in his hand. He hade bought a 3D printer (http://www.ultimaker.com/), assem­bled it and printed the cas­ing the same evening. He esti­mated the cost for print­ing a cas­ing to around €1. Pretty impressive!

We have been con­sid­er­ing buy­ing a 3D printer for quite some time now so I guess we are now run­ning short of excuses.