156B Week 6

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• • Have driving walker prototype ready for coding and testing.

  • Drivetrain design ongoing. Arrival of ordered parts at end of week.

Accomplishments from Previous Week

• • Installed Ubuntu on our PCs and ROS software - started testing.

  • Installed electrical hardware onto the walker - battery, motors provided by Mr. Wolfson, Raspberry Pi controller, H bridge, ultrasonic sensors. The walker can be controlled and tested using code on the microcontroller in this setup. (Pending final drivetrain)

  • Implemented a filter for Pozyx signal - needs testing

  • Started modeling base for charging station

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• • Get the walker driving through keyboard commands. Once this goal is accomplished autonomous driving can be implemented. -Sebastian and Jordan

  • Have a base built to test if battery can be charged using the contacts. - Fuad

  • Finish drivetrain design by Friday 2/16 for solenoid or clutch approach (decide). Continue rapid prototyping using 3D printing -Ivan

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• • Met with Mr. Wolfson on Friday 2/9. We discussed progress and our plans. 

  • We were encouraged to have presentable hardware for next meeting. We have actually implemented the hardware this week

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• At proof of concept presentation on 2/6, Dr. Tustaniwkyj suggested purchasing certain components that are readily available instead of using 3D printing (e.g. XL series belt pulley). Actions taken: improved print settings were used to produce a part that performs better than initially using 3D printing. In the case of this part, lightness is an asset as it reduces the rotational inertia of the drivetrain. Though McMaster does offer a lightweight acetal pulley, it doesn’t have the required profile for mounting. Still, the suggestion will be considered in the future.

  • Encouraged to look for Beryllium Copper contacts. Spoke to Tom about the possibility

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

• • N/A

Risks and Areas of Concern

• • Unsure of direction for drivetrain (disengagement mechanism) pending arrival of electromagnetic clutch and testing later this week.

  • We are concerned that ROS might not be the appropriate software to use for our system since it requires a steep learning curve. Also ROS required quite some computing power, which the PI might struggle with. As an alternative we will implement our code from ground up

  • and read and write from and to files.

Resources or Information Required but not Available

• • N/A

Schedule

• Upcoming milestones:

  • Walker final component assembly starting 2/23 through 3/5.

  • Charging system implemented by 2/23.

  • Charging docking testing 2/23 through 2/27.

  • Drivetrain implemented by 2/22.

  • Feedback Control/ROS implemented by 2/22.

• Gantt Chart updated for Week 6

Budget (list amount spent and amount remaining)

• Spent last week: $45.19

• Remaining: $896.77

Progress on Report and Webpage

• Report Rough Draft written by Friday 2/9

• Webpage Rough Draft completed by Friday 2/9