Stesalit has been a front-runner in developing its own R&D and development team for Embedded Design Services. Unlike many other companies, which forayed in to the space more as a remote provider, Stesalit was unique in developing its own products in this area which is successfully designed and presently in use with many of the major industries in automotive, railways and utility sector.
Hardware capability includes
Services Offered by Embedded Design Services Division :
- Micro Controller based system design utilizing TI, Motorola, Intel, Microchip, Hitachi,
- Analog/Digital signal processing
- PID controllers
- Power supply design and Power electronics
- Optimization of existing circuitry/designs
- Design and Development of Electronic Systems (Product Development Services)
- Development of Firmware (Application software, Communication software, Graphical User Interfaces, Device drivers and RTOS, Interface protocols, Assembly level programming)
- Development of Application Software ( Graphical user interfaces and Device drivers, Development of DSP based software and DSP libraries, Communication using standard or proprietary protocols)
- Re-Engineering & Optimization of Electronic systems and software
- PCB Design and Development ( Design of 2-14 layer PCB's using PCAD 2002, Cadence Allegro (PCB Design Studio), Cadstar and ORCAD packages, PTH to SMT conversion and manufacturing files generation considering DFMS, DFT and compliance issues , PCB Designing following the guidelines of the client and IPC standards, PCB manufacturing files (Gerber files) generation from schematic)
- Verification and Validation (Testing services encompass Complete FRS- Functional Requirement Specification, SDS- Software Design Specification, FAT- Factory Acceptance Test, IQ -Installation Qualification, OQ -Operational Qualification, PQ (Performance Qualification), UAT -User Acceptance Test Industry specific standards such as DO-178B and provide documentation to suit the customer needs)
Legacy Data Migration
Dynamic System Modeling tools
Software Modeling Tools
ADSP, Intel, Motorola 68Hxx, Hitachi, TI and Microchip.
Mathworks Matlab, Mathworks- simulink, Labview
VXWorks, Embedded Linux, WindowsCE, QNX, Proprietary operating systems
Rational Rose, Raphsody
Compilers and emulators such as AVRJTAGICE for ATMega Controllers C51 from Keil for 80C51 Controllers Hi-TIDE from HiTech for Microchip PIC Code Warrior for Motorola
Universal Serial bus, CANbus, Profibus, Modbus, Embedded TCP/IP
R&D Infrastructure of Stesalit
|The setup of the R&D unit of Stesalit is certified for ISO 9001-2000 and it follows the standard product life-cycle steps in developing a product to convert a concept into a product. A product life-cycle begins first with the conception phase when the techno-commercial feasibility of the product is thoroughly studied after which the prototype development is taken up. The working team is formed during this phase for the job and a development schedule is undertaken to complete the design within a targeted time frame. The developed sample is then put into thorough testing in the lab and also in the field to identify the defects, non-conformities and weaknesses in the design. Occasionally this involves redesign of the prototypes depending on the requirement.
After successful testing and field trial of the prototype, it is offered to the customer for evaluation.
This again involves elaborate lab testing and field evaluation with close monitoring of performance of
the equipment. Third party Safety Validation, if required for a product, is taken up at this stage.
This comprises the second phase of development.
Based on the successful outcome of the customer evaluation, the system then undergoes a product engineering cycle to take care of all its weaknesses which gets identified during customer evaluation and optimize its manufacturing cost. This comprises the third phase of development. Often, the second and third phase gets overlapped to cut down the development time. Test jigs and test softwares, as applicable, are also developed during this phase to ensure quality production. Occasionally it takes two to three passes to convert a prototype into a true manufacturing item. One important aspect of development is documentation, which is taken up in parallel at every phase of development.
Highlights of the R&D Infrastructure of Stesalit
- Core competence in processor embedded design using 8-bit, 16-bit and 32-bit microcontrollers.
- Expertise in developing Fail-Safe products meeting international safety norms.
- Experienced design team to convert a concept into a product.
- Undertakes both hardware and software design specific to user requirement.
- Availability of development equipments like incircuit emulators, logic analysers, storage scopes, Gate Array design system, PCB Artwork etc all under one roof
Product Development Life Cycle
|List of Products under Manufacturing
A. Microcontroller Embedded Products for Electric Locos
B. Microcontroller Embedded Products for Coaches
- Fault Diagnostic and Control System, FDCS 9648
This is a microcontroller embedded system, which takes care of all the operations of the loco. It has replaced a number of interlocking relays of the loco, which have been taken care of in the software for better performance. It also monitors and logs various faults encountered by the loco for better maintenance. The system is based on dual 80C196KC 16 bit microcontroller. Since the loco is totally controlled by the processor, the architecture includes dual redundancy in both hardware and software with 2-out-of-2 voting logic to take care of reliability and safety of operation of the loco. This is the first of its kind to be tried out in Indian Railway for indigenously built locos. Quite a few systems have been installed and commissioned in locos, which are working satisfactorily for the last two years.
- Electronic Speed and Energy Monitoring and Recording Unit for Locos
As the name implies, the unit monitors and records the speed of the loco and energy consumed by it with the distance traveled. The equipment is mounted on the driver's desk so that he is fully aware of the speed of the loco. The unit is considered as a safety device for them so that they can properly follow the speed restrictions during the course of his journey. The unit is based on 8-bit PIC microcontroller from Philips. More than 200 hundred numbers of such units are already in operation in Indian Railways.
- Traction Motor Control Unit, OmniTRACK
Conventional locos are driven by multiple DC traction motors and its speed is controlled by combining the motors in series and parallel during coasting, shunting, braking etc. Normally, the combinations are done through some interlocking relays, which are prone to failures. The TCCU is a PLC based system, which configures the motor combinations by driving the cam-shaft contactors based on driver's command. The system is based on Allen Bradley MicroLogics-1200 PLC. The system also has builtin fault diagnostic feature for better maintenance of the locos.
- Electronic Rectifier cum Regulating Unit, ERRU
Power required inside the coaches is primarily generated by an alternator coupled to the axle of the wheels. The AC power generated is then rectified and used by the coach load and is also stored in a battery bank for use during stationary condition. Since the speed of the coaches varies during its journey, the voltage generated by the alternator varies widely. ERRU is a microcontroller based control system, which regulates the field current of the alternator and stabilises the output voltage to within 1% compared to 10-15% with conventional magnetic amplifier based regulator. It has also appreciably reduced the cut-in speed limit after which the generation starts. There are two models, ne for 4.5KW alternator and another for 25KW alternator. This is again the first of its kind to be introduced in Indian Railways. The system is based on 80C196KC 16-bit microcontroller. Advantages are better power generation and longer battery life. More than 800 units are presently in operation in the field.
- Microcontroller based AC Control Panel, ACCP
In conventional air-conditioned coaches, temperature inside the coach is normally maintained by simple bi-metallic strip type thermostats. Reliability of these thermostats is very poor and so most of the time the ambient condition inside these coaches is very uncomfortable, either too low or high. It also does not have any control on the humidity of air, which also adds to the discomfort. ACCP is a microcontroller based monitoring and control system, which ensures the comfort of the passengers by maintaining both temperature and humidity within a preset limit. It also monitors the energy consumed by the compressors, condensers and the blowers to find out the performance of the air-conditioning unit. Although such controllers are now-a-days very common with room air-conditioners, our controller is again the first of its kind to be introduced in Indian Railways. The system is based on 80C196KC 16-bit microcontroller. Advantages are better comfort level for the passengers and performance. It also monitors and logs various faults for better maintenance.
C. Microcontroller Embedded Fail-Safe Signalling Products
- Phase Reversal Type Digital Axle Counter, DXC-02
Railway Signalling is directly related to safety of passengers and all its products have to meet some safety norms specified by the customer. Axle Counters have been introduced as part of Railway signalling system to avert accidents that resulted from train parting within a block section. So far, analog axle counters were tried out at various stations with limited success, primarily because of the sensitivity of the axle sensor against spurious noise, EMI and drifts. Digital Axle Counter DXC-02, uses state of the art phase detection technique with dual redundant 2-out-of-2 architecture for axle sensing to give a complete fail safe solution.
The system has been designed with Intel 80C196Kcmicrocontroller and meets RDSO specification for Digital Axle Counter SPN/177/2003 with latest amendments. It also meets CENELEC safety requirement specifications EN50126, EN50128 and EN50129. The system has been approved by Railway inspection Authority (RDSO) to be introduced in bulk in Indian Railways. It has also been safety validated by an independent agency, Center for Knowledge Based Systems, Jadavpur University to confirm its safety level to SIL-4 standard.
- Data Logger for Signalling Relay Interlocking Panel, DL4096
Conventional railway signalling is carried out through a relay interlock panel to ensure safe movement of trains. Even for a small station, hundreds of relays are required with thousands of interconnection wires to implement the logic. Relays are prone to failure and in case of a problem with a relay or a contact, signal operation gets stuck. Locating a fault in such a huge jungle of relays and wires is a real difficult job and often takes quite a long time to solve. DL4096 is a data logger which scans the status of all the signalling relays of a station with a resolution of 20 msec. and computes online to locate a fault for ease of maintenance. The system is expandable from 128 channels for a small system to 4096 channels suitable for big stations. It also accepts some analog channels expandable from 16 to 128. The system stores all transitions, alarms and events with time stamp upto 1 million records, which can be retrieved later to simulate the activation sequence of the signalling gadgets. This is very useful to analyse the reason of failure of signalling system during an accident. The system has been designed with 32-bit Motorola PowerPC microcontroller, MPC555 to cope with the computational power required for processing the huge volume of data generated in real time.
- Integrated Control Communication System, ICCS
Smooth movement of a train is the result of a concerted effort of a number of operational departments in Railway. Operations of each of these departments are distributed over a number of stations. The success of uninterrupted train movement is dependent on a close coordination among the operational staff working at various places. Communication among the operational staff of each functional group is carried out through some dedicated voice channels, working in conference mode. These channels are normally called as Control Communication Channels. In a particular station, the voice channel is extended to the subscriber with the help of Way-Station equipment, operated by an external power supply with battery backup. Such equipments have been found to be fail-prone because of their complexity and reliability, hampering the service. The Integrated Control Communication System offers an integrated approach to overcome all such problems and provides advanced subscriber facilities, in line with the present day communication system. Apart from control communication, the subscriber can use the same telephone as intercom within the station area. He can also access the nearby railway exchange to talk to anyone within the network. The system has been designed with Intel 80C196KC 16-bit microcontroller. All the subscriber access features are programmable which is stored in a non-volatile flash memory. It also has builtin Network Management feature to monitor the health of the equipment in a network for ease of maintenance. More than 50 such systems are already working in Indian Railway for the last one year. Indian Railway is now planning to introduce the product in a big way in their communication network.
D. Microcontroller Embedded Products under development
- Electronic Governor for diesel locos
In conventional diesel locos, injection of fuel in master cylinder is controlled by a governor depending on the coasting speed. Governors are normally a mechanical device, which is susceptible to detuning and failures. Efficiency of the diesel engine is also dependent on the performance of the governor. The objective of the electronic governor is to replace the existing maintenance intensive mechanical governor and improve the performance and efficiency of the diesel engines. The heart of the system is a 16-bit 80C196KC microcontroller. The system has builtin safety feature to ensure retraction of the fuel injection rack in case a failure is detected inside or outside the system.
- Microprocessor based Diesel Loco Control System
This is a complete control of a diesel locomotive. The system includes the following features of the diesel locomotive for its operation.
a. Excitation control
b. Propulsion Control
c. Dynamic Braking Control
d. Wheel Slip Control
e. Auxiliary Generator Control
f. Online Fault Diagnostics
The system uses multiple processors to perform the individual functionalities. Each of these is an Intelligent Front End and is based on TMS430F4xx 16-bit microcontroller from Texas. The central computer is based on ARM-7 based microcontroller LPC2144 from Philips. Redundant hardware has been used at various stages to ensure reliability and safety. Interconnection among the intelligent front ends have been carried out with dual redundant optic-fiber cable to eliminate the problem of EMI.
- Solid State Block Instrument for Railway Signalling
Solid State Block Proving by Axle Counter, SSBPAC has been conceived by Indian Railway as a replacement of the conventional Block Instrument which is going to be phased out very soon. The equipment picks up the status of some switches and signalling relays from one station, which is exchanged, with that of the other station. Axle counter provides the presence or absence of a train in the block section. Necessary interlocking and proving of logic is performed by the processor through its software and finally issues the signal information for train movement through a fail-safe relay. The system design is based on ARM-7 based microcontroller LPC2144 from Philips using triple hardware redundancy with 2-out-of-3 validity logic to take care of safety as well as availability. The system meets CENELEC safety requirement specifications EN50126, EN50128 and EN50129.