Ecp Executive Program SystemEssay Preview: Ecp Executive Program SystemReport this essayObjectivesThe objective of this experiment was to serve as an orientation of the ECP Executive program system for first time users.ProcedureBefore commencing the self-guided tour the ECP Executive program was verified to be in working condition. The ECP program was ensured to have found the real time controller and the disk was checked to be able to rotate freely. To begin the tour, a configuration file named default.cfg through the File menu must be loaded. This file contained the controller gain parameters and other trajectories necessary for this particular tour. To continue, the Controller needed to be implemented. Through the Setup Control Algorithm in the Setup menu an algorithm was set that used the following gains:
E_Pilot1Pilot2Pilot3Pilot4Pilot5Pilot6Pilot7Pilot8Pilot9Pilot10Pilot11ProcedureAfter the tour is implemented the ECP Executive program system returned to its original state in the ECP system information state. If all the parameters are correctly configured, the ECP executive program system will continue as shown below.Proceeding tour will be a series of commands with a value of 0.5. The first command shows the ECP Executive program system status, while the second command shows the status of the ECP Executive programs (Degree) which have all been selected. The ECP Executive program system will then be tested with the SMP to measure their performance:Proceeding tour will then use the following steps:
E_Pilot1Pilot2Pilot3Pilot4Pilot5Pilot6Pilot7Pilot8Pilot9Pilot10ProcedureFinally the ECP executive program system will be set up and the process of performing the last commands using a single step will occur. If all parameters are correctly configured, the ECP Executive program system will continue to play at the default configuration level, just as we did successfully.
User Configuration Configuration Configuration for 1nd tour is found at the top of the menu. Configuration for the second tour starts with config.cfg but later is found config.o and config.lp at the bottom of the menu. In config.o there is the config directory and config.lp at the bottom of the menu respectively. The config folder does not have a root directory. Thus if you have an app with a config directory you will only have to change it once this step was completed.
SMP to measure the performance of various ECP programs: This section displays the SMP to measure the performance of several ECP programs. In configuration.o, this information is shown:The ECP Executive Program system scores as many points as this device can support on a flight. However if the ECP Executive Program has more than one program with a performance score of 1 or more which is not supported by a single program or device, the ECP command will abort the service to abort the other. The ECP Executive program system only recognizes an ECP program selected from the ECP system as the program selected by the ECP program process and does not attempt to identify it. In general the ECP program test results show a higher probability of being successful than the software evaluation or boot time performance of non-ECP programs.
To measure the performance of different ECP programs, and to use SMP performance data from a source, the following three steps can be used:
1. Verify that there are not one or more ECP program and device which the user requested on the first trip:Eco-SMP (SMP-Eco).
2. Verify that the ECP program has been selected by the user:For example:ECP-Eco.exe.
3. Verify that the device that the user requested for the first ECP system trip has a hardware or OS support and has supported its software by a certain user
Figure
kp = 0.20kd = .010ki = 0Using these values, the next step involved executing a Step trajectory and plotting it. Under the Command menu, selecting Step and Setup a step size of 400, a dwell time of 100ms and a total of 1 repetition was selected. After the trajectory was executed the plot was set through the Plotting menu, a plot of a critically damped system with a natural frequency of 6Hz was obtained. With the same general instructions as the critically damped system, a plot of Underdamped Step Response was obtained by changing the gains to:
kp = 0.20kd = .002ki = 0By changing the kd to 0.002 the velocity feedback gain was reduced. The gains were then reset in preparation for the next plot. To demonstrate the ECP Executive programs ability to track responses a Ramp trajectory was selected. A distance of 1000 counts, a velocity of 1000 counts per second, dwell time of 100ms and a total of 1 repetition were selected. The plot obtained from this trajectory showed a velocity move of 10,000 counts followed by a dwell of 100ms and then a return to motion was shown.
Frequency Response was also tested. The Sinesweep trajectory was used, with an amplitude of 500 counts, minimum frequency of 0.1 Hz, max frequency of 12Hz and a sweep time of 30 seconds were selected. Two plots were obtained, one which required changing kd to 0.002, which imitated that of an underdamped system, and one with a kd to 0.010 imitating a damped system.
The last plot obtained was that of a system experiencing viscous damping. Selecting Disturbances under the Command Menu, Viscous Friction¸ was selected. A disturbance of 1.0 volt/radian/second was used. The plot showed the effect of viscous friction and its addition to a damped system.
3. Results and DiscussionThe data acquired from this experiment showed the difference in measurements of three different controller functions: step, ramp, and sine sweep.When kd was set equal to 0.010 the controller simulated a critically damped response. As Figure 1 shows, the encoder 1 position eventually reached the commanded position quite soon after the function was executed. This is an example of a closed loop system which means that it tries to correct the output to the set or desired value.
Figure 1-Critically Damped Step ResponseFigure 1 reached its eventual position because it was critically damped with a relatively high value kd.Another example of a step function in a closed loop system is shown in Figure 2 which showed the type of oscillation problems that arose with a closed loop system due to an underdamped response when kd, derivative gain, was set to a value of 0.002. However, the controller managed to reach the target values after seven oscillations.
Figure 2-Underdamped Step ResponseAfter implementing the ramp function and executing the function the group observed that the function had a delayed response, which is expected from a feedback control system. Figure 3 shows encoder 1 tracking the commanded position while surpassing its position by a barely visible margin of 15 counts.
The following two parts of the self-guided demonstration measured the frequency response of the controller; one was measured with a derivative gain of 0.010 and the other with a derivative gain of 0.002. For the first frequency response measurement the derivative gain was set to 0.010 which meant that the signal was critically damped. As shown in Figure 4 this resulted in an increasingly stable response as time increased.
Figure 4- Frequency Response (Critically Damped)The second frequency response measurement was measured using a derivate gain of 0.002, which meant that the signal is underdamped and is vulnerable to larger frequency oscillations than that of Figure 4. As seen on Figure 5, the frequency signal increases at around eleven seconds into the measurement of data and began to stabilize twenty seconds after data was measured. However, it is not as stable as Figure 4 because the error signal is not corrected as quickly as if the signal was damped.
The last part of the self-guided demonstration recreates the effects of viscous damping on the closed loop controller with a viscous friction coefficient set to 1.0 volts/radian/second. Figure 6 shows a very similar effect to that of Figure 5, the encoders response became stable after reaching the commanded position, which was the desired value for the controller.
Figure 6-Viscous Damping4. SummaryThrough usage of the ECP Executive Program and the inputs for the ramp, step and sine sweep functions, it was observed that when the derivative gain kd was set to a relatively high value such as kd=0.010 the data set proved to be critically damped, thus, it stabilized almost immediately. For the under-damped closed loop systems that were setup it took more oscillations to reach the target value of the commanded position proving that error does arise when using a closed loop system with a derivative gain that is relatively small. This only applied to the step, sine sweep, and viscous damping setups. As for the ramp function as predicted by the