Cost Effective Automated Test Framework for Touchscreen HMI Verification

Transcription

1 Cost Effective Automated Test Framework for Touchscreen HMI Verification Aby N Raj 1, P. Booma Devi, M.E., (Ph.D.) 2, Sajan Kumar 3, P. Sreekalesh 4,, S. Arathy 5 1 PG Scholar, R.V.S College of Engineering, Dindigul, Tamilnadu, India 2 Assistant Professor, R.V.S College of Engineering, Dindigul, Tamilnadu, India 3,4,5 TATA Elxsi, Trivandrum, Kerala, India Abstract Verification is a vital phase in any product development life cycle. Verification can be done in all stages of the development life cycle which will enhance the product quality but cost wise, it will consume a major share from the total system development cost. In addition to this, manual verification is also expensive in terms of manpower as well as time of completion. So a cost effective approach in verification phase will reduce the product development cost. In the case of touch screen device, the verification of screen transitions is one part of the device testing. But the solutions available in the market are very expensive. So this proposed method brings out a low cost automated test framework for testing touch screen devices screen transitions. This will be achieved using the general purpose software development tools and commonly used hardware components. The proposed system uses a digital camera for image capturing, MATLAB inbuilt models for image comparison and a 8 bit target board to drive the motors for triggering the touch input. The test frame work shall control the sequence of the test execution starting from triggering the touch till the result updating in the report. Keywords Verification, touchscreen, image comparison, test framework, camera. I. INTRODUCTION Verification is the process of evaluating a system or a product whether it complies with the requirements. Verification is an internal process which can be done on all phases of the product development life cycle like, specification development, design, implementation, integration, etc. In all these stages, verification can be done so that the errors shall not carry over to next phases. After the specification development, those product specifications can be verified with respect to the product or system requirements. In the Design phase simulations can be used to understand the behavior of each block in the proposed system. In the development stage verification can be done using various tools like emulators, development kits etc. The coverage of testing will be ensuring by mapping the test cases generated with respect to the requirements. So in brief, verification is a process which can be done in all stages. A. Static Verification Static verification is the set of processes that analyzes to ensure defined practices are being followed, without executing the application itself. This type of verification will be used for low volume production lines. By this approach we can ensure that the system or product is adhering to the requirements. B. Dynamic Verification Dynamic verification has been following by most of the organizations. They mainly concentrate on the classic quality assurance or quality control testing. This extends from unit and functionality testing as well as regression testing. The commonly used tool for unit testing is Tessy or open source tools such as Lint. C. Automated Verification In the case of manual verification there are limitations in terms of execution time, accuracy and limitation in the coverage of the test case. Automated verification can overcome all these drawbacks. Test cases will run n number of cycles without any manual intervention which tells the robustness of the system being tested. In addition, time critical related operations can also be verified. So, once the automated system is ready for run, that same setup can be used for regression testing. In this way, automated verification brings efficiency in terms of cost saving. D. Touch Screen A touchscreen is a display device that the user can control through simple or multi-touch gestures by touching the screen with one or more fingers. The touchscreen enables the user to interact directly with what is displayed. Touchscreens are common in devices such as Smartphone, tablets etc. Touchscreens are found in the area where other user interaction cannot fit into. There are various types of touchscreen based on the touch sensing methodology like resistive touchscreen, capacitive touchscreen, infrared touchscreen, etc. 636

2 II. CONVENTIONAL METHOD Verification of touchscreen devices is not a straight forward implementation. If it is a device with normal screen, we could test the device with initiating some functionality and then capture the screen image and perform an image comparison. But for touchscreen devices, the user interactions are also required. These user interactions are based on the functionality of the devices. There are various methods and systems which can do the automated verification of touchscreen devices. But mostly the solutions are high costly and a low scale production line cannot afford it. So this study aims to figure out a low cost verification system which also can run without the help of a full time tester. III. EXISTING METHOD There are several methods for atomizing verification of touch screen devices. A common approach includes an Autobox which is having dedicated processing capability with configurable IOs. The signal generator will be used to feed different streams required for the testing environment. The high resolution cameras are used and it is interfaced with PC using Ethernet. Highlights of existing method are listed in Table-1: TABLE I EXISTING METHOD # Highlights Existing options 1 Image capturing High-end cameras and its interfacing PC applications Eg: Cognex camera and VisonPro application 2 Image comparison MATLAB models and image processing/comparison algorithms 3 Test Frame Automation Desk which helps to populate test routines graphically without programming knowledge A. Drawbacks Major drawbacks of using the generally available test systems are listed below. a. Required costly peripherals like Cognex cameras. b. Used multiple software development platforms c. Required a high development time. d. High maintenance cost. e. Required professionals to maintain the system IV. PROPOSED METHOD The proposed work overcomes the drawbacks of the generally used automation system. Highlights of proposed method are mentioned below. The main aim is to find the low cost possibilities for: a. Cameras and its interfacing PC application b. Motors are driven to generate touch input c. Image capturing and test frame work software developments d. Test report generation Efforts have been in place since then to develop a cost effective reliable platform to automate testing. A. Objectives of Proposed method Objectives of the proposed method are to design and develop a low cost automated design verification system for touchscreen devices. The proposed system is capable to automate: 1. Test case execution: Test case execution will run each test case one by one and update the test result in the test report. In addition to the capability of running all test cases, the system will run the test cases for multiple cycles. 2. Touch control: The touch input is simulated using a control circuitry, which use 3 motors for the movement of x, y, z directions. These three motors will be driven individually by a microcontroller. This will eliminate the use of complex robotic arms and its respective circuitry. 3. Capture screen images: Normal digital cameras like Canon (price less than 200USD) will be used for image capturing. This will avoid the use of high cost cameras like Cognex which is 10 times higher than the normal digital cameras. The camera is connected to PC via USB interface. This reduces the complexity of the interface between PC and the camera. 4. Verify the images: Instead of newly developed models, usage of MATLAB inbuilt models will reduce the development cost. 5. Log the results: Instead of dedicated applications, use MS Excel for test reports. Normally in all PCs, MS office is available. So no additional cost is required for report generation tool and Excel MACROS will be developed to project the results overview automatically. B. System Model The System model is shown in Figure 1. Touchscreen device is the device which undergoes testing and needs to be mounted in the test frame. 637

3 The motors are placed in parallel to the touch screen. PIC 18 is controlled from PC via RS232 interface. PC sends the coordinates to PIC18 and the controller drives the motors to deliver the touch input. Then the desired screen will get displayed. The images of the display will be captured using the digital camera. This capturing will be done remotely by the software running in PC. For this, the Standard Development Kit (SDK) from the camera manufacturer will be used as the driver and the user application will be placed on the top of it. The camera is connected to the PC using USB interface. The captured image will get compared with the reference image. Based on the comparison, result will be updated in the test report. After the touch, the motors shall be driven back to the origin so that the cameras will get a clear field for capturing pictures. For the next test, these steps will be repeated. C. Generic Implementation For generalizing the device which needs to be tested, an algorithm is developed in which it is taking input from a mapping table which is unique for each touchscreen device. For generalizing the usage of camera which is using for image capturing, an abstraction layer is implemented which is holding the SDK interface. For generalising the usage of microcontroller board, the application layer is avoided with the microcontroller dependent usage. In brief, the generic way of implementation helps the system maintenance as well as the upgrading process very easy. D. Work breakdown This work involves design, development, integration and testing phase as shown in Figure 2. FIGURE 2 SPLIT-UP OF PROPOSED WORK This is similar to the phases in the embedded product life cycle. In the design phase, the hardware architecture, software architecture and the mechanical frame are modelled. Hardware architecture involves designing a PIC18 based development board with RS232 and digital IO interface. Mechanical frame is capable of holding the touchsceen device, the motors in parallel to the touchscreen and the camera facing the touch screen for capturing pictures. In the PC, the C#, MATLAB and the MPLAB software needs to be installed. Once the hardware setup is ready, the embedded programming for PIC18, C# programming for image capturing, MATLAB coding for image comparison and the Excel MACROS for report generation have been developed. After the development, the testing will be carried out and after the successful minimum cycles of run, the product will be ready for demonstration. FIGURE II PROPOSED AUTOMATED SYSTEM 638

4 The integrated environment overcomes the problems which are normally pop up while dealing with multiple software components. In this research, the product development life cycle is followed to ensure the objective is achieved within the planned time. V. RESULTS AND DISCUSSION The test frame which is an integrated execution environment, trigger the PIC controller for touch input, capture the image, compare the image and update the result in the report. Automation is ensured by the system's capability to run the test without any user intervention. The analysis of cost effectiveness is done and it s captured below. a. Development time of this solution is reduced 60% when compared to the development time required while using the individual development tools figure 3. b. Cost of this automated solution is reduced 69% (avg) when compared to the solutions available in market figure 4. c. Since the tool complexity is reduced, the maintenance cost will also be less. d. The generic way of implementation enables the system upgrade easy. FIGURE 3 DEVELOPMENT TIME COMPARISON FIGURE 4 COST RELATION VI. CONCLUSION This work proves the approach of low cost automation for touch screen devices. The use of general software tools like Microsoft C#, MATLAB and hardware component like stepper motors, PIC18 8bit microcontroller target board makes this solution cheaper. This low cost test setup eliminates the requirement of high cost systems for the design verification of touchscreen devices. The scope of future work is to search for the possibility to reduce cost further by replacing MATLAB with a suitable open source. Acknowledgements Here we thank all those who have directly or indirectly contributed in the successful completion of this paper. We are thankful to Asst. Prof. P.Booma Devi for the valuable guidance and encouragement throughout the completion of this work. REFERENCES [1 ] Kastelan I, Kordic B, Pekovic V, Teslic N, Test-Case Creation Framework for Touchscreen-Based Device Testing transform using grayscale morphology decomposition, Engineering of Computer Based Systems 3rd Eastern European Regional Conference ECBS- EERC 2013, pp [2 ] Ivan Kastelan, Nikola Teslic, Mihajlo Katona, Dusan Zivkov, Touch screen simulation for automated verification of touch screen based devices, IEEE 19th International Conference and Workshops on Engineering of Computer-Based Systems 2012, pp [3 ] Mihajlo Katona, Ivan Kastelan, Vukota Pekovic, Nikola Teslic, Tarkan Tekcan, Automatic Black Box Testing of Television Systems on the Final Production Line, IEEE Transactions on Consumer Electronics, Vol. 57, 2011, pp

5 [4 ] Pekovic V, Teslic N, Resetar I, Tekcan T, Test management and test execution system for automated verification of digital television systems, Consumer Electronics (ISCE), 2010 IEEE 14th International Symposium, pp [5 ] Ki-Uk Kyung, Jun Young Lee, Jun-Seok Park, Pen-like Haptic Interface and Its Application on Touch Screen, Robot and Human interactive Communication, RO-MAN 2007, The 16th IEEE International Symposium, 2007, pp [6 ] Ivan Kaštelan, Mihajlo Katona, Vukota Peković, Velibor Mihić, Automated Functional Verification of Digital Television Systems using Camera, 52 nd International Symposium ELMAR-2010, [7 ] Ivan Kaštelan, Nikola Teslić, Vukota Peković, Tarkan Teckan, TV Screen Content Extraction and Recognition Algorithm for the Verification of Digital Television Systems, 17th IEEE International Conference on Engineering of Computer-Based Systems (ECBS), 2010, pp [8 ] Dušica Marijan, Nikola Teslić, Miodrag Temerinac, Vukota Peković, "On the effectiveness of the system validation based on the black box testing, IEEE Circuits and Systems International Conference on Testing and Diagnosis, [9 ] H.R. Sheikh, A.C. Bovik, Image information and visual quality, IEEE Transactions on Image Processing, vol. 15, 2006, pp [10 ] YAO Xiaotong, WANG Ziting, "Application of image capturing system based on TMS320C6713 using in vehicle identification system", Automation & Instrumentation, Chongqing, May 2006, pp