A crossbar assembly for facilitating isolation of a sensor assembly from vibration comprises an outer crossbar segment, an inner crossbar segment, and an isolator. The outer crossbar segment comprises a payload mount interface and an outer isolator interface operable to mount to an isolator. The inner crossbar segment comprises a structure interface and an inner isolator interface operable to mount to the isolator. The isolator can be supported by the outer and inner crossbar segments. The isolator comprises a first wire rope assembly comprising wire ropes extending longitudinally from the outer crossbar segment to the inner crossbar segment, and a second wire rope assembly comprising a wire rope extending circumferentially between the outer and inner crossbar segments. The isolator operates to partially decouple the outer crossbar segment from the inner crossbar segment and dampen vibrations propagating between the outer and inner crossbar segments.

A crossbar assembly for facilitating isolation of a sensor assembly from vibration comprises an outer crossbar segment, an inner crossbar segment, and an isolator. The outer crossbar segment comprises a payload mount interface and an outer isolator interface operable to mount to an isolator. The inner crossbar segment comprises a structure interface and an inner isolator interface operable to mount to the isolator. The isolator can be supported by the outer and inner crossbar segments. The isolator comprises a first wire rope assembly comprising wire ropes extending longitudinally from the outer crossbar segment to the inner crossbar segment, and a second wire rope assembly comprising a wire rope extending circumferentially between the outer and inner crossbar segments. The isolator operates to partially decouple the outer crossbar segment from the inner crossbar segment and dampen vibrations propagating between the outer and inner crossbar segments.

A crossbar system for facilitating isolation of a sensor assembly from external vibrations of a support structure. The crossbar system comprises first and second crossbar assemblies and a payload mount, Each of the first and second crossbar assemblies comprises a crossbar segment and a slip plate damper. Each crossbar segment comprises a payload mount interface at a first end of the crossbar assembly and a first support structure interface at a second end of the crossbar assembly. Each slip plate damper is disposed about the crossbar segment and is slidably coupled to the crossbar segment to constrain movement in two lateral degrees of freedom and to facilitate movement in a longitudinal degree of freedom, Each slip plate damper comprises a second support structure interface at the second end of the crossbar assembly. The payload mount is coupled to the payload mount interfaces of the first and second crossbar assemblies.

A crossbar system for facilitating isolation of a sensor assembly from external vibrations of a support structure. The crossbar system comprises first and second crossbar assemblies and a payload mount, Each of the first and second crossbar assemblies comprises a crossbar segment and a slip plate damper. Each crossbar segment comprises a payload mount interface at a first end of the crossbar assembly and a first support structure interface at a second end of the crossbar assembly. Each slip plate damper is disposed about the crossbar segment and is slidably coupled to the crossbar segment to constrain movement in two lateral degrees of freedom and to facilitate movement in a longitudinal degree of freedom, Each slip plate damper comprises a second support structure interface at the second end of the crossbar assembly. The payload mount is coupled to the payload mount interfaces of the first and second crossbar assemblies.

In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for receiving an indication that a vehicle has begun accelerating from a stationary state. A computing system sets, in response to having received the indication that the vehicle has begun accelerating from the stationary state, an orientation value generated using a gyroscope to a default orientation value. The computing system repeatedly updates the orientation value generated using the gyroscope, based on changes in gyroscope orientation that occurred after the computing system set the orientation value to the default orientation value. The computing system determines that the updated orientation value satisfies criteria that indicates that the vehicle is likely to encounter or has encountered a dangerous situation. The computing system outputs a signal to cause the vehicle to employ a safety measure.

In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for receiving an indication that a vehicle has begun accelerating from a stationary state. A computing system sets, in response to having received the indication that the vehicle has begun accelerating from the stationary state, an orientation value generated using a gyroscope to a default orientation value. The computing system repeatedly updates the orientation value generated using the gyroscope, based on changes in gyroscope orientation that occurred after the computing system set the orientation value to the default orientation value. The computing system determines that the updated orientation value satisfies criteria that indicates that the vehicle is likely to encounter or has encountered a dangerous situation. The computing system outputs a signal to cause the vehicle to employ a safety measure.

A hybrid inertial measurement unit (IMU) comprises: a low frequency (LF) sensor providing a first signal containing information for a first parameter of the hybrid IMU; a shock resistant (SR) sensor providing a second signal containing information for the first parameter, wherein the SR sensor is resistant to destabilization during a destabilizing operational period; and a processor, wherein the processor further comprises: a weighting factor computation module to compute a weight to be applied to the first signal and to compute a weight to be applied to the second signal; a LF weighting module to apply the computed weight to the first signal to create a weighted first signal; a SR weighting module to apply the computed weight to the second signal to create a weighted second signal; and a compensator to combine the weighted first signal and the weighted second signal to create a compensated signal containing information for the first parameter.

A hybrid inertial measurement unit (IMU) comprises: a low frequency (LF) sensor providing a first signal containing information for a first parameter of the hybrid IMU; a shock resistant (SR) sensor providing a second signal containing information for the first parameter, wherein the SR sensor is resistant to destabilization during a destabilizing operational period; and a processor, wherein the processor further comprises: a weighting factor computation module to compute a weight to be applied to the first signal and to compute a weight to be applied to the second signal; a LF weighting module to apply the computed weight to the first signal to create a weighted first signal; a SR weighting module to apply the computed weight to the second signal to create a weighted second signal; and a compensator to combine the weighted first signal and the weighted second signal to create a compensated signal containing information for the first parameter.

A cardan joint includes a cross-elevation assembly comprising a cross-elevation housing, a roll-elevation assembly comprising a roll-elevation housing, a payload interface assembly comprising a payload interface housing, and a suspension interface yoke comprising a suspension interface that couples the suspension interface yoke to one or more suspension bars. The roll-elevation assembly is rotatably connected to the cross-elevation assembly along a first rotation axis via a radial roller bearing and a thrust roller bearing. The payload interface assembly is rotatably connected to the roll-elevation assembly along a second rotation axis via a radial roller bearing and a thrust roller bearing. The suspension interface yoke is rotatably connected to the cross-elevation assembly along a third rotation axis via one or more radial roller bearings and one or more thrust roller bearings. The payload interface housing comprises a payload interface operable to couple the payload interface housing to an inertially stabilized payload.

A cardan joint includes a cross-elevation assembly comprising a cross-elevation housing, a roll-elevation assembly comprising a roll-elevation housing, a payload interface assembly comprising a payload interface housing, and a suspension interface yoke comprising a suspension interface that couples the suspension interface yoke to one or more suspension bars. The roll-elevation assembly is rotatably connected to the cross-elevation assembly along a first rotation axis via a radial roller bearing and a thrust roller bearing. The payload interface assembly is rotatably connected to the roll-elevation assembly along a second rotation axis via a radial roller bearing and a thrust roller bearing. The suspension interface yoke is rotatably connected to the cross-elevation assembly along a third rotation axis via one or more radial roller bearings and one or more thrust roller bearings. The payload interface housing comprises a payload interface operable to couple the payload interface housing to an inertially stabilized payload.