TORQUE SENSOR AND FORCE SENSOR

Transcription

1 TORQUE SENSOR AND FORCE SENSOR The A3 - ULC is designed to fulfill a wide range of customer specific application requirements. The A3 - ULC can be easily mounted to a customer designed sensor holder. To adjust the sensor output to a customer specific torque or force range the sensor can be calibrated by performing a 2-point-calibration. The temperature calibration can be done for customer specific materials and needs. Measurements can be performed on any ferromagnetic shaft or rod. Best performance is achieved with hardend steel (approx. 56 HRC) designed with a SF (safety factor) between 4 and 20. A sturdy sensor mount is necessary to ensure a stable output signal. Applications Automotive E-Mobility Power train Hydraulics Weighing technology Benefits N Contactless N No damage to Mechanical Overload N Adaptable to Customer Specific Applications N Digital Output (UART, CAN, SPI) N Temperature Compensation (coming soon) N Hysteresis Compensation (coming soon) N Digitally Linearized Output Signal N Unaffected by External Magnetic Fields Datasheet 07/2017 Technical Drawing Trafag GmbH Germany Kelterstraße Unterensingen Tel Fax Page 1/5 info@trafag.de

2 Applications Sensor system performance specifications are valid for: Shaft Material: 45NiCrMo16 Shaft Hardening: HRC56 Magnetization: Degaussed (Remanent Magnetization < 4 mt) Mechanical Design: Safety Factor between 4 to 20 Distance between sensor and test-object: 0.5 mm Mounting the Sensor For best performance, no relative movement beween measurement object (i.e. the shaft) and sensor should be possible. It is recommended to clamp the sensor directly to the measurement object. An example for such a mount for a 25 mm shaft is given below. Mechanical forces acting on the sensor housing, the sensor mount and the sensor s cable will lead to signal offsets. This should be taken into account to achieve best results. Preparation of the test object The measurement object must be made from a ferromagnetic material. Hardening of the material is strongly recommended to reduce errors due to Hysteresis effects of unhardened materials. Axial loads can only be measured reliably, if bending forces are minimized.¹ Specification Electrical Specification Parameter² Min Typical Max Unit Measurement Power Consumption mw Start-up Time ms ESD Protection (HBM) kv Signal Output Sample-Rate Hz Communication Interface Costumer specific (UART, SPI, CAN, tbd) ¹ The compensation of bending forces is possible with customized sensor solutions. ² Values are defined for a temperature of 25 C Page 2/5

3 Specification Parameter³ Min (SF 20) Typical Measurement (SF 10) Max (SF 4) Measurement Range (Nm) unlimited Nm Nm Torque and Force, absolute Accuracy ± 1.5 ± 1.0 ± 0.5 % FS Torque and Force, signal resolution ± 0.01 ± 0.01 ± 0.01 % FS Torque and Force, repeatability ± 0.06 ± 0.3 ± 0.2 % FS Torque and Force, nonlinearity ± 0.25 ± 0.25 ± 0.25 % FS Signal Noise ± 0.06 ± 0.03 ± 0.02 % FS Torque and Force, hysteresis ⁴ ± 0.5 (± 0.1) ± 2 (± 1) ± 3 (± 1) % FS Distance Sensitivity % FS Material SF (Safety Factor) Limits ⁵ SF Response time ⁶ ms Temperature Range ⁷ C Temperature Dependency (uncalibrated) ± 3 ± 1.5 ± 0.6 % FS / 10 K Temperature Dependency (calibrated) ± 0.4 ± 0.2 % ± 0.1 % FS / 10 K Temperature Sensor Output Accuracy ± 0.5 ± 0.5 ± 0.5 C Sensor Aging % FS / year Unit Sensor Performance Graphs 3,50 Temperature Accuracy 3,00 2,50 Torque (±% FS) 2,00 1,50 1,00 0,50 0, Temperature [ C] ³ Values are defined for a temperature of 25 C. ⁴ By applying a customer material specific hysteresis compensation the impact can be reduced below 1 % FS. In generally the hysteresis effect depends on material and hardening. ⁵ Safety Factor (SF) is defined as the maximum material tension yield point in MPa divided by the maximum torque or force load to the measurement object in MPa. ⁶ Depends on the bandwidth of the whole system sensor response time is dominated by the adjusted bandwidth ⁷ Upper temperature is limited due to the electronic components. For OEM solutions a temperature up to 125 C is possible. Page 3/5

4 7,000 Hysteresis Dependency of Safety Factor 6,000 5,000 Torque (±% FS) 4,000 3,000 2,000 1,000 0, Safety Factor [SF] Influence of material choice and heat treatment on sensor performance The measuring principle of the torque and force sensor is contactless. Mechanical stress in the shaft or rod is measured by detecting changes in the magnetic material properties due to external forces. As a consequence, inhomogeneity s within the object can lead to signal changes when the measurement position is changed, e.g. the shaft is rotating. Possible causes for such spatial inhomogeneity s are: Remnant magnetization, Microstructure of the alloy and Internal stress. While a remnant magnetization can be reduced by careful degaussing of the object, other influences cannot be controlled afterwards. For best sensor performance, the choice of alloys showing minimal segregation during steel production is advisable. During further tooling and machining of the test object any process affecting the homogeneity of internal stress and microstructure should be avoided. Heat treatment of the object changes the material properties and therefore our sensor signal. The exact influence depends on many factors and is not easily predictable. A general observation for many alloys is a reduced signal hysteresis after hardening of the object. In order to achieve this beneficial effect, a surface hardening >= 2 mm is sufficient. Connector Specification USB Connector Recommended Operating Conditions The sensor shows best performance when operated within the recommended temperature and torque range. Long term exposure to conditions outside of this range may temporarily offset the torque signal. Prolonged exposure to extreme conditions may accelerate ageing. To ensure stable operation, the conditions described in the section of Electrical Specifications and General Specifications must be met. Please note this does apply for transportation, storage and operation of the sensor system. Page 4/5

5 Important Notices Device Certification The A3 - ULC torque and force sensor complies with RoHS and WEEE regulations. Warnings / Disclaimer / Warranty Do not use the A3-ULC product as safety or emergency stop devices or in any other application where failure of the product could result in personal injury. Do not use this product for applications other than its intended and authorized use. The Sensor must only be handled by professionals in the field of electronics and engineering who are experienced and trained in observing good engineering standards and practices. Before installing, handling, using or servicing this product, please consult the data sheet and user guide notes. Failure to comply with these instructions could result in serious injury. DO NOT open the sensor module; it does not contain user serviceable parts. Trafag is not liable for any tampered sensors and the cost of service will be negotiated on occasion. All products are thoroughly tested before shipping and assumed to be defect-free unless proven otherwise. Contact Trafag if you have questions about the suitability of the Sensor Kit for a specific application. The standard Sensor Kit is designed for indoor use only. Warranty Trafag GmbH warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of delivery that this product shall be of the quality, material and workmanship defined in Trafag`s published specifications of the product. Within such period, if proven to be defective, Trafag shall repair and/or replace this product, in Trafag`s discretion, free of charge to the Buyer, provided that: notice in writing describing the defects shall be given to Trafag within fourteen (14) days after their appearance such defects shall be found, to Trafag reasonable satisfaction, to have arisen from Trafag faulty design, material, or workmanship; the defective product shall be returned to Trafag factory at the Buyer s expense; and the warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by Trafag for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN, TRAFAG MAKES NO WARRAN- TIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRAN- TIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED. Trafag is only liable for defects of this product arising under the conditions of operation provided for in the data sheet and proper use of the goods. Trafag explicitly disclaims all warranties, express or implied, for any period during which the goods are operated or stored not in accordance with the technical specifications. Trafag does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Recommended parameters can and do vary in different applications. Trafag reserves the right, without further notice, (i) to change the product specifications and/or the information in this document and (ii) to improve reliability, functions and design of this product. Support / Contact Trafag GmbH Kelterstr Unterensingen Germany For product information, sales, service and technical support: Worldwide +49 (0) info@trafag.de Or visit us online at: Trafag GmbH T orque and Force Sensor Page 5/5