Due to the complexity of real-world powertrains the information model must be highly modular. This means that OPC UA objects must be provided which are not too fine granular but enable to represent the majority of existing devices by combining them. The level of granularity was chosen to be on basic component level like motor, encoder and brake. These entities are called assets (PtAssetType) and have one or more components holding their asset attributes (PtAssetAttributesType). Also, it´s possible to model a software asset type e.g. firmware by using the PtAssetType.
The powertrain information model is based on two main object types:
Table 13 – Powertrain Object Types
|
1. |
PtAssetType(powertrain asset type) |
Represents an orderable part of the powertrain. It serves as a container for the asset's attributes. The most common attributes of asset types are added as mandatory components. e. g. motor and encoder for servo motor. |
|
2. |
PtAssetAttributesType(powertrain asset attribute type) |
Asset attributes are split into two categories. Some of the common asset attributes apply to all asset types (e.g., ambient temperature). Specific asset attributes apply only to some subset of asset types, (e.g., MotorPolePairs applies to several motor related asset types). |
Some asset types have a one-to-one relation to an PtAssetAttributesType like PtAssetEncoderType to PtEncoderAttributesType. Others have a one-to-many relation e. g. a gear motor PtAssetGearMotorRoteryType has mandatory properties of type PtGearAttributesType and PtMotorRoteryAttributesType. A complex asset like PtAssetServoDriveType has to be decomposed into the predefined component asset attributes like PtInputConverterAttributesType and PtOutputConverterAttributesType.
Figure 10 shows the powertrain information model basic structure. Subtypes of PtAssetType have attributes which are subtypes of PtAssetAttributesType.
Figure 10 – Information Model Overall Structure
Besides the asset attributes which are directly associated to an asset there are also common asset attributes found in a powertrain which may be used in multiple assets. These are defined under PtCommonAssetAttributesType and cover domains like standards, hardware or ambient conditions.
Figure 11 – PtCommonAssetAttributesType
Figure 12 shows asset types grouped into drive component related, switchgear related and motor related assets. The swim lanes shall illustrate the energy flow through drive and motor. The frequency converter is shown with an orange frame and is split into assets like control module, input converter, DC bus and output converter. Below the low voltage switchgear related assets include e.g. a contactor that simply switches current on and off to the motor. A more complex setup uses a motor starter.
Figure 12 – Example Asset Types of a Powertrain
The following table gives an overview of the available asset types and their asset attributes. The asset terms are described in chapter 6.3.
Motor / Motor Components related AssetTypes
Motor component related asset types contain the motor itself and devices which are mounted near the motor to measure actual data or affect the motion output.
Table 14 – Motor / Motor Components related AssetTypes
|
AssetType |
AssetType Definition in Chapter |
Subtype of |
AttributesTypes |
|
PtAssetMotorType |
PtAssetType |
|
|
|
PtAssetMotorRotaryType |
PtAssetMotorType |
|
|
|
PtAssetMotorLinearType |
PtAssetMotorType |
|
|
|
PtAssetDriveIntegratedMotorRotaryType |
PtAssetMotorRotaryType |
|
|
|
PtAssetDriveIntegratedMotorLinearType |
PtAssetMotorLinearType |
|
|
|
PtAssetGearMotorRotaryType |
PtAssetMotorRotaryType |
|
|
|
PtAssetGearMotorLinearType |
PtAssetMotorLinearType |
|
|
|
PtAssetDriveIntegratedGearMotorRotaryType |
PtAssetDriveIntegratedMotorRotaryType |
|
|
|
PtAssetDriveIntegratedGearMotorLinearType |
PtAssetDriveIntegratedMotorLinearType |
|
|
|
PtAssetEncoderType |
PtAssetType |
|
|
|
PtAssetEncoderRotaryType |
PtAssetEncoderType |
|
|
|
PtAssetEncoderLinearType |
PtAssetEncoderType |
|
|
|
PtAssetBrakeType |
PtAssetType |
|
|
|
PtAssetGearType |
PtAssetType |
|
|
|
PtAssetTemperatureSensorType |
PtAssetType |
|
|
|
PtAssetVibrationSensorType |
PtAssetType |
|
Drive Components related AssetTypes
Drive components related asset types contain building blocks of a drive like input and output converter and control module. These building blocks should be sufficient to compose a drive of any type.
Table 15 – Drive Components related AssetTypes
|
AssetType |
AssetType Definition in Chapter |
Subtype of |
AttributesTypes |
|
PtAssetEncoderInterfaceType |
PtAssetType |
|
|
|
PtAssetBleedType |
PtAssetType |
|
|
|
PtAssetElectricalBrakingModuleType |
PtAssetType |
|
|
|
PtAssetDcBusModuleType |
PtAssetType |
|
|
|
PtAssetInputConverterType |
PtAssetType |
|
|
|
PtAssetOutputConverterType |
PtAssetType |
|
|
|
PtAssetInputOutputConverterType |
PtAssetType |
|
|
|
PtAssetInputFilterType |
PtAssetType |
|
|
|
PtAssetInputReactorType |
PtAssetType |
|
|
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PtAssetOutputFilterType |
PtAssetType |
|
|
|
PtAssetOutputReactorType |
PtAssetType |
|
|
|
PtAssetCommunicationModuleType |
PtAssetType |
|
|
|
PtAssetControlModuleType |
PtAssetType |
|
|
|
PtAssetIoModuleType |
PtAssetType |
|
|
|
PtAssetSafetyModuleType |
PtAssetType |
|
|
|
PtAssetCoolingType |
PtAssetType |
|
|
|
PtPrechargeType |
PtAssetType |
|
Complete Drive Devices related AssetTypes
The PtAssetDriveType serves as a generic container while subtypes PtAssetFrequencyConverterType or PtAssetVariableSpeedDriveType are for the user’s convenience to express a specific class of drives. Another intention is to make some components mandatory as PtAssetMotorRotaryType for PtAssetDriveIntegratedMotorType.
Table 16 – Complete Drive Devices related AssetTypes
|
AssetType |
AssetType Definition in Chapter |
Subtype of |
AttributesTypes |
|
PtAssetDriveType |
PtAssetType |
|
|
|
PtAssetFrequencyConverterType |
PtAssetDriveType |
|
|
|
PtAssetVariableSpeedDriveType |
PtAssetDriveType |
|
|
|
PtAssetServoDriveType |
PtAssetDriveType |
|
Switchgear related AssetTypes
Switchgear related PtAssetTypes contain devices that can be used to control, protect and monitor an asynchronous motor, and sometimes associated with a variable speed drive described in a separate section.
Table 17 – Switchgear related AssetTypes
|
AssetType |
AssetType Definition in Chapter |
Subtype of |
AttributesType |
|
PtAssetContactorType |
PtAssetType |
|
|
|
PtAssetElectricOverloadRelayType |
PtAssetType |
|
|
|
PtMotorStarterType |
PtAssetType |
|
|
|
PtSoftStarterType |
PtAssetType |
|
|
|
PtMotorManagementDeviceType |
PtAssetType |
|
The modular approach of the information model is shown in an example in Figure 13. A PtAssetMotorRotaryType, representing a servo motor, has properties of PtAssetAttributesType for the rotary motor, rotary encoder and brake. A PtAssetServoDriveType is a subtype of PtAssetDriveType and has additional encoder asset attributes. Motor and servo drives can of course have arbitrary numbers of objects of the PtCommonAssetAttributesType.
Figure 13 – Detailed Example of an Information Model Structure