Migration to the new Housing Finished

Today we finished the migration of our hardware into the new frame and housing. After fixing the usual problems with the off-the-shelf components and some teething troubles with the wiring, we could run our first successful ‘walking’ tests just this weekend. The housing now contains the complete robotic system, including cameras, illumination, communication, and –most importantly- the specimen collector.
In contrast to our initial plan of having a drill-like collector, we decided to go for a simpler shovel mechanism that is just lowered into the ground and filled by slowly sliding the robot forward. It looks a little bit like a bird’s beak.
Mechanical benefits are the increased stiffness with some reduction in weight, and additional sensors to measure all joint angles. Additionally the robot is now fully protected against environmental influences. However, we’re not planning of putting it in the rain until the competition is over.
The upcoming week is fully designated to testing. The main focus will thereby be on the cooperation of the individual systems. That means, looking at the communication, power consumption, and maneuverability in the dark. Another goal is to get some long term operation experience before we have to pack our boxes and ship them to Tenerife. We want to figure out witch components are working well, and which are prone to error while we’re still able to patch. Other issues that we couldn’t yet examine are friction, wear, and especially heat accumulation and its influence on the different components.
The fine-tuning and finalization of the locomotion concept will be done on the spot in Tenerife were we can test in the actual conditions and environment of the competition.

Rollout of the 1.2-Protoype at the Night of Science in Zurich

Everything was on an extremely tight schedule for the preparation of the Night of Science. After pulling some long, long evenings, we finished the new prototype literally in the very last minute. Some of the final assemblies were actually done in the exhibition tent. The great effort of the students was rewarded by an extremely open and interested crowd that was drawn in large numbers to our booth.
The only drawback was a small error in the NI-software. It sometimes caused misinterpretations of the sensor signals and made demonstrations impossible. Still, we got good feedback and the new prototype was a real highlight in the exhibition; especially for the younger visitors.

Spill Winch for the Tether System

As we decided to have a tethered power supply (and climbing aid) for our legged robot, we were in need for some device to pull the power line and the robot out of the crater. After unsuccessfully looking for a traditional of the shelf solution, we decided to create our own spill winch. This design has the advantage that there is no need for slip ring connections and that the effective cable pull is easy to control by the small pre-loading system.

Supporting Robot ‘Crabli’ is Test-Ready

After Thomas finished his test series on different suspension systems on the ‘Crabli’-Robot, we were able to mount our additional equipment on it. Besides an extension battery pack, we added a (night vision) camera, a wireless repeater, and a strong LED light source. Mark is currently simplifying the control interface and we’re running tests focusing on the remote controllability and the range of the WiFi signal.
For this robot the LRC will be the first field mission, and we’re really curious about its locomotion abilities in such a harsh environment.

Development of the GUI and Communication started

Slowly we have to deal with the question of how to control our robot from afar. The computational functions like generation of joint trajectories and their realization in the controller have to be equipped with well defined interfaces and have to be able to communicate with each other. While this has been mostly solved for internal communication (using the TCP-IP connection), we are now working on the communication with the operator. Dealing with questions how the motion of the robot is being provided and controlled.

New Computational System Successfully tested

In a breadboard environment we evaluated the idea of directly reading the sensor information via the cRIO system. This would eliminate the need for additional servo boards at each leg and frees the CAN-Bus from some of its load. We also would have additional 16 analog channels available, which can for example be used to monitor the motor temperatures. Digital filters were implemented in the FPGA and the control code was ported to NI LabView were it runs in real-time at with a higher frequency.
So far the move seems to be a great success. And with the new singleboardRIO, it will become feasible to have the computation on board without adding a lot of additional weight.

New Backbone Ready

The workshop has finished manufacturing of the new robot frame. Currently the composite casing is being built. Together they will provide a very stiff framework for the mechanical components and will also provide a dust-prove housing for the electronic components. With this step the mechanical redesign for the robot is finished and we can move on to integrate the specimen collecting mechanism. We also created a prototype for the textile cover of the legs. This was one of the critical issues, as we suspected that part of the fabric might jam the joint motion. However, preliminary test seemed promising.