Group 4 2014 - Revision history

PatrickChang at 15:52, 12 December 2014

2014-12-12T15:52:18Z

← Older revision		Revision as of 11:52, 12 December 2014
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	''Group Members: Alex Lind, Cristian Salgueiro, Casey Trimble''		''Group Members: Alex Lind, Cristian Salgueiro, Casey Trimble''

			[[Media:jumping-aerated-granular.pdf\|Final Report]]

Jump2014: /* Hard Ground Results */

2014-12-10T02:23:01Z

Hard Ground Results

← Older revision		Revision as of 22:23, 9 December 2014
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	===Hard Ground Results===		===Hard Ground Results===

	[[File:HardGroundNormOne.png \| thumb \| left \| 250px \| Results]]		[[File:HardGroundNormOne.png \| thumb \| left \| 250px \| Results of hard ground jumps. Plotting max height/A vs. mg/kA]]
	[[File:HardGroundEquilTwo.png \| thumb \| right \| 250px \| ~~Simple schematic~~ of ~~the jumping robot apparatus~~.]]		[[File:HardGroundEquilTwo.png \| thumb \| right \| 250px \| Results of hard ground jumps. Plotting max height/(mg/k) vs. mg/kA]]

	To the left and right are the plots for the hard ground jumps. On the left is a plot of the heights normalized to the forcing amplitude versus our nondimensional parameter, $mg/kA$. The plot on the right is similar, except the heights are normalized to the equilibrium position, defined as $mg/k$.		To the left and right are the plots for the hard ground jumps. On the left is a plot of the heights normalized to the forcing amplitude versus our nondimensional parameter, $mg/kA$. The plot on the right is similar, except the heights are normalized to the equilibrium position, defined as $mg/k$.

Jump2014: /* Granular Media Results */

2014-12-10T02:21:53Z

Granular Media Results

← Older revision		Revision as of 22:21, 9 December 2014
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	===Granular Media Results===		===Granular Media Results===

	[[File:HeightsPlot.jpg \| thumb \| 350px \| ~~Simple schematic of~~ the ~~jumping robot apparatus~~.]]		[[File:HeightsPlot.jpg \| thumb \| 350px \| Results for the granular media jumps. Plotting maximum height vs. time]]

	In single jumps, the maximum amplitudes were plotted as the frequency of forcing was systematically increased. Shown in Figure , it is evident that there is an optimum jump frequency, which has been found in previous research. The frequency that yielded the highest jump was $5.375Hz$.		In single jumps, the maximum amplitudes were plotted as the frequency of forcing was systematically increased. Shown in Figure , it is evident that there is an optimum jump frequency, which has been found in previous research. The frequency that yielded the highest jump was $5.375Hz$.

Jump2014: /* Granular Media Results */

2014-12-10T02:21:14Z

Granular Media Results

← Older revision		Revision as of 22:21, 9 December 2014
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	===Granular Media Results===		===Granular Media Results===

	[[File:HeightsPlot.jpg \| thumb ~~\| left~~ \| 350px \| Simple schematic of the jumping robot apparatus.]]		[[File:HeightsPlot.jpg \| thumb \| 350px \| Simple schematic of the jumping robot apparatus.]]

	In single jumps, the maximum amplitudes were plotted as the frequency of forcing was systematically increased. Shown in Figure , it is evident that there is an optimum jump frequency, which has been found in previous research. The frequency that yielded the highest jump was $5.375Hz$.		In single jumps, the maximum amplitudes were plotted as the frequency of forcing was systematically increased. Shown in Figure , it is evident that there is an optimum jump frequency, which has been found in previous research. The frequency that yielded the highest jump was $5.375Hz$.

Jump2014: /* Results */

2014-12-10T02:20:25Z

Results

← Older revision		Revision as of 22:20, 9 December 2014
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	===Hard Ground Results===		===Hard Ground Results===

	~~Below~~ are the plots for the hard ground jumps. ~~Figure 1~~ is a plot of the heights normalized to the forcing amplitude versus our nondimensional parameter, $mg/kA$. ~~Figure~~ is a similar ~~plot~~, except the heights are normalized to the equilibrium position, defined as $mg/k$.		[[File:HardGroundNormOne.png \| thumb \| left \| 250px \| Results]]
			[[File:HardGroundEquilTwo.png \| thumb \| right \| 250px \| Simple schematic of the jumping robot apparatus.]]

			To the left and right are the plots for the hard ground jumps. On the left is a plot of the heights normalized to the forcing amplitude versus our nondimensional parameter, $mg/kA$. The plot on the right is similar, except the heights are normalized to the equilibrium position, defined as $mg/k$.

	The plot nondimensionalized to forcing amplitude does not match well with theory. In our experimental results, the single jump outperforms the stutter jump at low $\alpha$, but the stutter jump outperforms the stutter jump at high $\alpha$. This is unfortunately contrary to theoretical results. The plot also has a strange decrease in amplitude as $\alpha$ decreases, which is also contrary to theoretical predictions. Part of this discrepancy could be better explained with a finer parameter sweep, specifically testing at more than just two amplitudes.		The plot nondimensionalized to forcing amplitude does not match well with theory. In our experimental results, the single jump outperforms the stutter jump at low $\alpha$, but the stutter jump outperforms the stutter jump at high $\alpha$. This is unfortunately contrary to theoretical results. The plot also has a strange decrease in amplitude as $\alpha$ decreases, which is also contrary to theoretical predictions. Part of this discrepancy could be better explained with a finer parameter sweep, specifically testing at more than just two amplitudes.
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	===Granular Media Results===		===Granular Media Results===

			[[File:HeightsPlot.jpg \| thumb \| left \| 350px \| Simple schematic of the jumping robot apparatus.]]

	In single jumps, the maximum amplitudes were plotted as the frequency of forcing was systematically increased. Shown in Figure , it is evident that there is an optimum jump frequency, which has been found in previous research. The frequency that yielded the highest jump was $5.375Hz$.		In single jumps, the maximum amplitudes were plotted as the frequency of forcing was systematically increased. Shown in Figure , it is evident that there is an optimum jump frequency, which has been found in previous research. The frequency that yielded the highest jump was $5.375Hz$.

Jump2014: /* Apparatus */

2014-12-10T02:12:00Z

Apparatus

← Older revision		Revision as of 22:12, 9 December 2014
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	== Apparatus ==		== Apparatus ==

			[[File:ExptSetup.PNG \| thumb \| left \| 150px \| Simple schematic of the jumping robot apparatus.]]

	The experiment utilizes an existing jumping robot in the Georgia Tech CRAB Lab. The diagram {DOSOMETHINGHERE} shows a schematic of the apparatus. The robot jumps on GM in a box resting above an air duct. In a simple jump, a linear actuator imposes a downward force on the rod, forcing the robot foot into the GM. The spring contracts, and the actuator is released causing the robot to jump. Both the actuator and the air flow are controlled and systematically varied in LabView.		The experiment utilizes an existing jumping robot in the Georgia Tech CRAB Lab. The diagram {DOSOMETHINGHERE} shows a schematic of the apparatus. The robot jumps on GM in a box resting above an air duct. In a simple jump, a linear actuator imposes a downward force on the rod, forcing the robot foot into the GM. The spring contracts, and the actuator is released causing the robot to jump. Both the actuator and the air flow are controlled and systematically varied in LabView.

	~~[[File:ExptSetup.PNG \| thumb \| left \| 350px \| Simple schematic of the jumping robot apparatus.]]~~

	In addition to varying air flow, we vary the spring constant of the foot. Our trials cover a range of flow rates for four different spring constants. We control the spring constant with a variable length spring, shown below.		In addition to varying air flow, we vary the spring constant of the foot. Our trials cover a range of flow rates for four different spring constants. We control the spring constant with a variable length spring, shown below.

Jump2014: /* Apparatus */

2014-12-10T02:11:18Z

Apparatus

← Older revision		Revision as of 22:11, 9 December 2014
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	The experiment utilizes an existing jumping robot in the Georgia Tech CRAB Lab. The diagram {DOSOMETHINGHERE} shows a schematic of the apparatus. The robot jumps on GM in a box resting above an air duct. In a simple jump, a linear actuator imposes a downward force on the rod, forcing the robot foot into the GM. The spring contracts, and the actuator is released causing the robot to jump. Both the actuator and the air flow are controlled and systematically varied in LabView.		The experiment utilizes an existing jumping robot in the Georgia Tech CRAB Lab. The diagram {DOSOMETHINGHERE} shows a schematic of the apparatus. The robot jumps on GM in a box resting above an air duct. In a simple jump, a linear actuator imposes a downward force on the rod, forcing the robot foot into the GM. The spring contracts, and the actuator is released causing the robot to jump. Both the actuator and the air flow are controlled and systematically varied in LabView.

			[[File:ExptSetup.PNG \| thumb \| left \| 350px \| Simple schematic of the jumping robot apparatus.]]

	In addition to varying air flow, we vary the spring constant of the foot. Our trials cover a range of flow rates for four different spring constants. We control the spring constant with a variable length spring, shown below.		In addition to varying air flow, we vary the spring constant of the foot. Our trials cover a range of flow rates for four different spring constants. We control the spring constant with a variable length spring, shown below.

Jump2014: /* Apparatus */

2014-12-10T02:07:54Z

Apparatus

← Older revision		Revision as of 22:07, 9 December 2014
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	== Apparatus ==		== Apparatus ==

	~~To investigate~~ the ~~dynamics~~ of a ~~jumper~~ with a variable ~~stiffness~~ spring... to ~~be continued very soon~~.		The experiment utilizes an existing jumping robot in the Georgia Tech CRAB Lab. The diagram {DOSOMETHINGHERE} shows a schematic of the apparatus. The robot jumps on GM in a box resting above an air duct. In a simple jump, a linear actuator imposes a downward force on the rod, forcing the robot foot into the GM. The spring contracts, and the actuator is released causing the robot to jump. Both the actuator and the air flow are controlled and systematically varied in LabView.

			In addition to varying air flow, we vary the spring constant of the foot. Our trials cover a range of flow rates for four different spring constants. We control the spring constant with a variable length spring, shown below.

			Data is collected with a force sensor on the jumper and a high speed camera. The force sensor records the force of the motor on the rod, and the camera tracks the motion of a tracking marker on the rod. With force, position, and time data, we show the change in jump dynamics as air flow and spring constant are varied. We compare our results to the theoretical predictions of the CRAB Lab.

	== Methods ==		== Methods ==

Jump2014: /* Experiment Videos */

2014-12-10T01:47:21Z

Experiment Videos

← Older revision		Revision as of 21:47, 9 December 2014
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	==Experiment Videos==		==Experiment Videos==

			<videoflash>j_CyJBfTNUc</videoflash>

	<videoflash>ocFDIMlPMds</videoflash>		<videoflash>ocFDIMlPMds</videoflash>

Jump2014: /* Experiment Videos */

2014-12-10T01:44:38Z

Experiment Videos

← Older revision		Revision as of 21:44, 9 December 2014
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	==Experiment Videos==		==Experiment Videos==

			<videoflash>ocFDIMlPMds</videoflash>

	==Results==		==Results==