Wedged three-axis inertial sensor damper-suspension
A wedge three-axis inertial sensor damper suspension apparatus prevents shock and vibration impacts on a construction machine from being transferred to inertial sensors used by an automatic control system of the construction machine. The inertial sensor suspension apparatus includes a pocket, a lid, a core disposed in the pocket and covered by the lid, one or more inertial sensors attached to the core, a plurality of elastomer insertions attached to the core and forming an upper wedge between the core and the lid and a lower wedge between the core and the pocket, and a coupler that provides controlled connection of the pocket and the lid to compress the plurality of elastomer insertions using a force corresponding to a target resonance frequency for the inertial sensor suspension apparatus.
1. An inertial sensor suspension apparatus mountable on a construction machine for preventing shock and vibration impacts on the construction machine from being transferred to one or more inertial sensors, comprising:
a pocket;
a lid;
a core disposed in the pocket and covered by the lid;
one or more inertial sensors attached to the core;
a plurality of elastomer insertions attached to the core and forming an upper wedge between the core and the lid and a lower wedge between the core and the pocket; and
a coupler that provides controlled connection of the pocket and the lid to compress the plurality of elastomer insertions using a force corresponding to a target resonance frequency for the inertial sensor suspension apparatus.
2. The inertial sensor suspension apparatus of claim 1 , wherein the core is cubic-shaped with pyramidal truncated corners, and the plurality of elastomer insertions comprise a respective elastomer insertion attached to each of the pyramidal truncated corners of the core.
3. The inertial sensor suspension apparatus of claim 1 , wherein the core is made of one of stainless steel, brass, or bronze.
4. The inertial sensor suspension apparatus of claim 1 , wherein the plurality of elastomer insertions are made of one of latex or silicon rubber.
5. The inertial sensor suspension apparatus of claim 1 , wherein the one or more inertial sensors comprise first, second, and third uniaxial inertial sensors attached to first, second, and third orthogonal faces of the core, respectively.
6. The inertial sensor suspension apparatus of claim 1 , wherein the coupler comprises a first screw that passes through the core and connect the lid to the pocket and is tightened to a target torque moment corresponding to a compression force on the plurality of elastomer insertions that results in a target total spring factor calculated to provide the target resonance frequency for the inertial sensor suspension apparatus.
7. The inertial sensor suspension apparatus of claim 6 , further comprising one or more second screws to lock the first screw at the target torque moment.
8. The inertial sensor suspension apparatus of claim 1 , wherein the target resonance frequency for the inertial sensor suspension apparatus is within the range of 150-200 Hz.
9. The inertial sensor suspension apparatus of claim 1 , wherein in response to an impact, the upper and lower wedges formed by the plurality of elastomer insertions act as a spring to produce oscillations due to the impact and act as a damper to attenuate those oscillations.
10. The inertial sensor suspension apparatus of claim 9 , wherein the upper and lower wedges formed by the plurality of elastomer insertions provide mechanical filtering of vibrations due to impacts and an amplitude frequency response of the inertial sensor suspension apparatus has a gain of one for a range of low frequencies less than the target resonance frequency, a resonance peak at the target resonance frequency, and attenuates high frequencies greater than the target resonance frequency to approximately zero.
11. The inertial sensor suspension apparatus of claim 10 , wherein a Q-factor of amplitude frequency response of the inertial sensor suspension apparatus is greater than or equal to 10.
12. A system comprising:
a construction machine having an operative organ;
one or more inertial sensors configured to measure at least one of acceleration or angular rate of the operative organ of the construction machine; and
an inertial sensor suspension apparatus for preventing shock and vibration impacts on the construction machine from being transferred to the one or more inertial sensors, the inertial sensor suspension apparatus comprising:
a pocket,
a lid,
a core disposed in the pocket and covered by the lid, wherein the one or more inertial sensors are attached to the core,
a plurality of elastomer insertions attached to the core and forming an upper wedge between the core and the lid and a lower wedge between the core and the pocket, and
a coupler that provides controlled connection of the pocket and the lid to compress the plurality of elastomer insertions using a force corresponding to a target resonance frequency for the inertial sensor suspension apparatus.
13. The system of claim 12 , wherein the core is cubic-shaped with pyramidal truncated corners, and the plurality of elastomer insertions comprise a respective elastomer insertion attached to each of the pyramidal truncated corners of the core.
14. The system of claim 12 , wherein the core is made of one of stainless steel, brass, or bronze, and the plurality of elastomer insertions are made of one of latex or silicon rubber.
15. The system of claim 12 , wherein the one or more inertial sensors comprise first, second, and third uniaxial inertial sensors attached to first, second, and third orthogonal faces of the core, respectively.
16. The system of claim 12 , wherein the coupler comprises a first screw that passes through the core and connect the lid to the pocket and is tightened to a target torque moment corresponding to a compression force on the plurality of elastomer insertions that results in a target total spring factor calculated to provide the target resonance frequency for the inertial sensor suspension apparatus.
17. The system of claim 16 , wherein the inertial sensor suspension apparatus further comprise one or more second screws to lock the first screw at the target torque moment.
18. The system of claim 12 , wherein the target resonance frequency for the inertial sensor suspension apparatus is within the range of 150-200 Hz.
19. The system of claim 12 , wherein in response to an impact on the construction machine, the upper and lower wedges formed by the plurality of elastomer insertions act as a spring to produce oscillations due to the impact and act as a damper to attenuate those oscillations.
20. The system of claim 19 , wherein the upper and lower wedges formed by the plurality of elastomer insertions provide mechanical filtering of vibrations due to impacts and an amplitude frequency response of the inertial sensor suspension apparatus has a gain of one for a range of low frequencies less than the target resonance frequency, a resonance peak at the target resonance frequency, and attenuates high frequencies greater than the target resonance frequency to approximately zero.