Emergency Stop Upgrade

This past week, on the hardware side, the team finally received the shipment of parts we needed to perform the emergency stop system upgrade to bring more actuators on the vehicle under emergency stop control. We also added a relay that was controllable by the software in order to allow LabVIEW to trip the emergency stop when necessary and also to ensure that any glitches or freezes in the software would trip the emergency stop even if the human operator failed to notice the software glitch. 

To do this, we essentially upgraded several essential parts:

1. We converted the only double-pole double-throw (DPDT) relay on the vehicle into a 3PDT relay to give us an additional channel controlled by the relay
2. We added an additional 3PDT relay to give us an additional 3 channels controlled by the relay
3. We added a DPDT relay with a 5V coil voltage to allow LabVIEW to control the relay. 

However, we made the mistake of failing to account for the fact that the NI9401 DIO module that we're using can't source enough current to run the relay. So, instead, we're attempting to use a transistor to allow us to source 1mA to drive a transistor in order to generate the 0.25A we need to drive the 5V DPDT relay. So, most of the system is now in place except for the LabVIEW control of the relay because we have yet to finish installing the transistor into the relay system. 

On the ROS front, we've made steady progress bringing in sensor data from LabVIEW to ROS and should soon begin installing ROS navigation stack packages. We originally set an initial test deadline for this coming week. However, with spring break occurring the week after this comign one and the fact that we have had a couple of delays in the project, we may push that test deadline back to the week after spring break or so.

​That's it for now!