Sensor time

您好, 我们的orin nx上接了四个鱼眼,四个鱼眼使用了硬同步。 我们测试下来情况如下:

getSensorTimestamp 为T1
获取的曝光时间 为 T2

T1 , T2

13783003.368000 ,0.508
13783003.542000 ,0.430
13783003.374000 ,1.760
13783003.460000 ,0.429

19353847.040000 ,9.083
19353846.955000 ,0.456
19353847.000000 ,0.433
19353847.073000 ,1.306

如果getSensorTimestamp 获取的时间为SOF时间,那么开始曝光时间为T3 = T1- T2

这样计算下来为

T1 , T2 , T3
13783003.368 ,0.508 , 13783003.368 - 0.508 = 13783002.860
13783003.542 ,0.430 , 13783003.112
13783003.374 ,1.760 , 13783001.614
13783003.460 ,0.429 , 13783003.031

19353847.040 ,9.083 , 19353837.957
19353846.955 ,0.456 , 19353846.499
19353847.000 ,0.433 , 19353846.567
19353847.073 ,1.306 , 19353845.767

那么这样计算下来4个相机的开始曝光时间相差了8ms了, 但是我们4个相机使用的是硬同步。这个时间差哪出问题了?

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The provided context appears to be a collection of documentation and forum posts related to NVIDIA’s Jetson platform, specifically the Jetson Orin NX and other Jetson modules. The context includes information on how to identify the type of Jetson module using the lsusb command, as well as various discussions and topics related to the Jetson platform, such as thermal management, partition configurations, and device tree bindings.

To answer your question, it seems that you are asking about the getSensorTimestamp function and its output on the Jetson Orin NX platform. The output you provided shows two sets of timestamps, labeled as T1 and T2, as well as a third set of timestamps labeled as T3 in the second output.

Based on the context, it appears that the getSensorTimestamp function is used to retrieve timestamps from sensors on the Jetson platform. The output shows two sets of timestamps, T1 and T2, which seem to be related to the sensor data. The third set of timestamps, T3, is only present in the second output and seems to be related to the SOFT3 sensor.

Without more information about the specific sensor and the context in which the getSensorTimestamp function is being used, it is difficult to provide a more detailed explanation of the output. However, it appears that the function is returning timestamps in a format that includes a large integer value followed by a smaller integer value.

In comparison to other Jetson platforms, the output of the getSensorTimestamp function may vary depending on the specific sensor and platform being used. However, the general format of the output, with two or three sets of timestamps, seems to be consistent across different platforms.

It’s worth noting that the context also includes information on how to obtain the correct compatible string for a Jetson platform, which may be useful for identifying the specific platform and sensor being used. Additionally, the context includes discussions on thermal management and partition configurations, which may be relevant to the use of the getSensorTimestamp function on the Jetson Orin NX platform.

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hello 550399056,

please use the Argus sample application, syncSensor for testing.
syncSensor sample is a software approach of software based synchronization, this example using multiple sensor per single capture session method, which means it’ll duplicate single capture request to these camera sensors.
BTW, it supports up-to 3 camera in single synchronization session, you may have two syncSensor session for your 4-cam use-case.

您好,

我们现在是硬同步的,使用的是pwm 触发信号来实现的硬同步。

我现在问题如上:

getSensorTimestamp 获取的是时间含义是什么?为什么会有上面的差异?

还有:

我看了下syncSensor 代码 ,他是计算直方图的相似性来评判是否多相机是否同步,而我们的需求是需要获取硬同步的情况下,多相机的曝光时间。 为什么或出现上面的现象

hello 550399056,

please see-also Topic 159220 for Argus Timestamp, SensorTimestampTsc.