Vehicle TestingReliable, stand-alone data-acquisition systems for laboratory and rugged field vehicle testing

用于车辆测试的数据采集

Granite™10数据采集系统设计有车辆测试。作为Campbell Scientific最具计算强大的数据采集系统，Granite™10是车辆测试数据采集网络的核心。提供四种通用频道，Granite™10是CAN总线，可以FD兼容。与Granite™测量模块集成时，完整的系统能够测量温度，应变，压力，负载和许多其他参数。Granite™10 DAQ可以同时支持多个测量速率，每秒每隔几个小时到10,000多个测量值。测量类型，处理算法和记录间隔也是可编程的。Granite™10 CAN 10 CAN总线允许从花岗岩™DAQ独立测量数据时同步存储车辆数据。

板载指令集包含程序化算法，该算法处理测量和输出导致所需的工程单元。例如，数据可以显示为雨流或级别交叉直方图。这些雨流程和级别交叉算法允许长时间的处理，而不仅仅是有限数量的循环。我们的指令集还允许基于时间或条件事件进行无人值守的测量和控制决策。

Modular Design

我们的Granite™系统的模块化架构允许每个测量模块直接连接到PC或DAQ。作为独立模块，可以直接显示在PC上的实时测量。一个或多个测量模块可以连接到Granite™10 DAQ，以为每个应用程序创建完美的网络配置。连接时，它们形成时间同步的分布式数据采集系统。

分布式网络和同步

Multiple GRANITE™ measurement modules can be distributed throughout the vehicle. Each module is connected to a central GRANITE™10 DAQ. This networking capability decreases the quantity and lengths of the sensor cables between the sensors and the GRANITE™10. Fewer sensor cables reduces cost, improves system simplification, and lessens the risk of signal corruption from noise.

同步是分布式网络成功的关键。Granite™DAQ同步有三个显着级别：

1. The GRANITE™10具有内置GPS和精密主时钟。
   1. The pulse-per-second signal from the GPS is accurate to 1 µs. If enabled, the GRANITE™10 will phase lock its operating clock to within 200 ns of the GPS clock. So, multiple independent DAQ systems spread over potentially vast geo-spatial regions can be synchronized with a maximum timing error between DAQ systems of 1.2 µs.
   2. 独立于GPS，温度补偿，高精度，车载，实时时钟将保持自己的时间，精度为±3分钟/年。
2. Within a single DAQ system, comprised of a GRANITE™10 and GRANITE™ measurement modules, the measurements are all synchronized to the master clock of the GRANITE™10 (sourced by either the GPS or precision on-board clock) via the CAN Peripheral Interface (CPI) or Ethernet Peripheral Interface (EPI) measurement buses.
1. 相同DAQ中测量模块之间的CPI同步为±5μs。根据数据速率，总线的整体物理范围可达2,000英尺。
2. 相同DAQ中测量模块之间的EPI同步为±50 ns。总线的物理范围为每网络连接300英尺。菊花连接的连接可以跨越数千英尺。
3. For extremely time-based-sensitive applications, the GRANITE™ SPECTRUM measurement modules are used with EPI synchronization. Within each module, the analog electrical signal delay is calibrated and compensated to reduce the timing delay mismatch to ±10 ns channel-to-channel.