Meeting Minutes:

Group Meeting 11

Meeting Date: 1-8-14

Meeting Time: 12:00-12:45

Members Present: All Members Present but Dean Gonzalez (excused absence for job, flying)

Accomplishments:

Group Meeting 12

Meeting Date: 1-10-14

Meeting Time: 12:00-1:30

Members Present: All Members Present

Accomplishments:

• Worked on updating the Project Plans and Product Specs deliverable

  • Read through paper as group

  • Divided up sections to update

  • Compiled final document

Group Meeting 13

Meeting Date: 1-12-14

Meeting Time ME’s: 3:00-5:00

Meeting Time EE’s: 2:00-5:00

Members Present: All Members Present

ME Accomplishments:

• Decreased length of lander plate from 8 in. to 2 in.

• Developed new idea of removing the leaf spring system and using rigid plates with torsional springs at base instead.

• Verified that rover roll pitch and elevation change would not have an adverse impact on the operation of new system.

  • The only possible problem with the new design is rover yaw affecting contact

  • The solution could be to place a gimbal type system (similar to a joystick) on the plate to allow for the desired degrees of freedom.

• Theorized that best material construction of rover plates would be similar to lander plate (fiberglass structure with thin sheet of copper on contacting surface).

• Identified problem with new design

  • If rover passed full contact point, the plates would separate

  • The solution is to put a weaker torsional spring on the lander plate, thus the two plates remain in contact at all times

• Worked out height and extension from lander deck that the arm would need to have

  • Approximately 21 in. down and 2 in. away from deck

  • Upon review of Dragon Plate (material used for prototyping) dimensions and connections, it was determined that a 6 in. extension away from the deck would be needed in order for the modular clevis connections to be able to be used (since the connections themselves are around 2 in. long)

• Talked about buying fiberglass kit at Home Depot to begin learning how to create fiberglass and how to set in mounting brackets

EE Accomplishments:

• Lander Battery Charge Cycle Testing

  • Connected power supply, voltmeter, and ammeter to ATRV-Jr. batteries and performed a charge test, sampling voltage and current every minute.

  • Charge current stayed below 100mA. This is theorized because the batteries began at a low voltage (~10V) and the power supply was trickle charging until a safe charge where it could bulk charge. Additional testing is needed and will be completed in the following days. Much higher current will be needed to simulate actual charge current

• Talked about possible methods of discharging batteries so that future experiments can be done

  • Solution 1: Use very low resistance resistors with high current to dissipate energy

  • Solution 2: Use approximately 4 high power light bulbs in series. It was determined that this would take around 8 hours to fully discharge the batteries

  • For the purposes of experimentation, the batteries will not need to be fully discharged, so the actual discharge time will be reduced significantly

Group Meeting 14

Meeting Date: 1-13-14

Meeting Time: 12:00-1:30

Members Present: All Members Present