Claims:We Claim:
1. A device for testing a sensor (106), the sensor (106) configured to measure a fill level, quality and at least a temperature value of a liquid, the device comprising:
an electrical connector adapted to connect to sensor (106) and transmit a communication protocol signals generated by the sensor (106) to a controller (102);
the controller (102) adapted to process said encoded communication protocol signals and calculate the value of fill level, quality and at least temperature based on the information in the communication protocol signals;
an output device (104a,104b) in communication with the controller (102), the output device (104a,104b) exhibiting the value of fill level, quality and at least temperature.

2. The device for testing a sensor (106) as claimed in claim 1, wherein the sensor (106) is designed to be placed inside an aqueous solution tank.

3. The device for testing a sensor (106) as claimed in claim 1, wherein the controller (102) is adapted to connect to an electric power source.

4. The device for testing a sensor (106) as claimed in claim 1, wherein sensor (106) generate an encoded communication protocol signal.
5. The device for testing a sensor (106) as claimed in claim 1, wherein the controller (102) decodes the received communication protocol signals.

6. A method for testing a sensor (106), the sensor (106) configured to measure a fill level, quality and at least a temperature value of a liquid, the method comprising;
transmitting a communication protocol signal generated by the sensor (106) to a controller (102) by means of an electrical connector;
decoding the received communication protocol signals by means of a controller (102);
calculating the values of fill level, quality and at least temperature based on the information in the decoded signals;
communicating the values of fill level, quality and at least temperature to an output device (104a,104b).

7. The method for testing a sensor (106) as claimed in claim 6, wherein the sensor (106) is designed to be placed inside an aqueous solution tank.
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of the invention
[0001] The present disclosure relates to a device for testing a sensor. More specifically it relates to a device for testing a sensor designed to be placed inside an aqueous solution tank.

Background of the invention
[0002] Modern day vehicles are built with complex electronic systems that make thousands of decisions based on the data provided by various sensors that are interfaced to the vehicles’ onboard computer systems. Many critical systems within the vehicle such as the exhaust gas aftertreatment system have components wherein the sensors are integrated within the components before its assembled on to the vehicle. Hence it is important to diagnose faulty sensors before they are integrated with the components and assembled onto the vehicle. One such example is that of the Diesel Exhaust Fluid (DEF) tank sensor that is used to measure fill level, temperature and ascertain quality of the DEF in the tank. These sensors are integrated inside a supply module comprising DEF tank, DEF heater and DEF filter. Once a faulty sensor is integrated inside a supply module, the whole supply module becomes redundant. Hence there is a need for sensor tester tool to detect any errors with the DEF sensor in a portable and cost-effective manner.

[0003] Japanese patent application “JP2009080068 A2” titled “ Sensor Tester” discloses a sensor connector 2; a programmable IC 3 on which a combination of analog circuits and digital circuits is mounted; a wireless module 4; an expansion connector 5; and a PLD 6 for variably configuring a wiring pattern circuit 60 between the electronic components. An expansion board 7 has the electronic components for expanding a function of the sensor tester 1 and is connected to the expansion connector 5. When the sensor tester 1 is implemented, the sensor connector 2 and the expansion connector 5 are disposed in the center on the surface and backside of one board. The other electronic components are disposed on the board so as to position the center of mass of the sensor tester 1 in the central region of the board.

Brief description of the accompanying drawings
[0004] An embodiment of the invention is described with reference to the following accompanying drawings:
[0005] Figure 1 depicts a device for testing a sensor (106);
[0006] Figure 2 depicts a component diagram for the device for testing a sensor (106);
[0007] Figure 3 illustrates method steps for testing a sensor (106); and at least
[0008] Figure 4 illustrates the PWM signals received by the controller (102).

Detailed description of the drawings

[0009] Figure 1 depicts a device for testing a sensor (106). The device comprises an electrical connector, a controller (102) and at least an output device (104a,104b). In one embodiment of the present invention the sensor (106) is configured to configured to measure a fill level, quality and at least a temperature value of a liquid inside a container. In an exemplary embodiment of the present invention, the sensor (106) being tested using the device herein disclosed is a Diesel Exhaust Fluid (DEF) tank sensor. Such sensors usually comprise an ultrasonic wave generator that works on Principle of Time of Flight (that varies according to the properties of the liquid), Reading the echoed signals wherein a simple Pulse width modulating PWM (High – LOW) signals can be seen. The device is a hand-held portable device and can be carried to different locations for sensor (106) testing. All the signal processing and the sensor (106) value (output) extraction is done in the controller (102).

[0010] Figure 2 depicts a component diagram for the device for testing a sensor (106). The device comprises components such as but not limited to an electrical connector, a controller (102) and at least an output device (104a,104b). Other components may include an electric power source (105), an I2C interface adapted to connect the controller (102) to an output device (104a,104b). The electrical connector is adapted to connect to sensor (106) and transmit a communication protocol (like PWM, SENT, CAN etc.) signals generated by the sensor (106) to a controller (102). The controller (102) is adapted to process said communication protocol signals and calculate the value of fill level, quality and at least temperature based on the information in the communication protocol signals. The output device (104a,104b) in communication with the controller (102), the output device (104a,104b) exhibits the value of fill level, quality and at least temperature.

[0011] The working of the device is explained by means of an exemplary embodiment, wherein the communication protocol is a Pulse width modulating (PWM) signal. The electrical connector adapted to connect to sensor (106) and transmit pulse width modulating (PWM) signals generated by the sensor (106) to the controller (102). The sensor (106) generate multiplexed (encoded) PWM signals. The electrical connector is a 5 or a 7pin connector adapted to connect to the sensor (106). In other words, the connector is compatible to adapt to the electrical connectors of any version of DEF tank sensor (106). Powering the sensor (106) is done by the device itself through the energy source (105) like using a battery or an adapter or with the laptop USB port or even a power bank, making it an easy-to-use at any place.

[0012] The controller (102) is adapted to process said PWM signals and calculate the value of fill level, quality and at least temperature based on the widths of the pulses in demultiplexed PWM. The controller (102) demultiplexes (decodes) the received PWM signals. The controller (102) can be a microcontroller (102) chip such as an ATmega328P based Arduino UNO board or even a small single-board computers (SBCs) such as a raspberry pi. The ATMEGA328P is high performance, low power controller (102) from Microchip. ATMEGA328P is an 8-bit microcontroller (102) based on AVR RISC architecture. All the signal processing and calculations are performed by the controller (102). The controller (102) also handles the sending of commands to the output device (104a,104b). Other controller (102)s like STM32 and clones of Arduino like Seeduino, Freeduino, Node MCU can also be used. For connecting to an output device (104a,104b) capable of network communication, Single-board computers like Beagle Boards, Raspberry pi boards can be used.

[0013] The output device (104a,104b) is in communication with the controller (102), and exhibits the value of fill level, quality and at least temperature. The output device (104a,104b) can be any one from the group of but not limited to an LCD (104A) display screen, any HMI interface, a computer, a mobile phone or any network device. In the embodiment of the invention, connection to the LCD (104A) is enabled via an I2C (103). I2C (103) is used to convert the 16-pin parallel connection from LCD (104A) to a 2-pin serial connection to Arduino, thus eliminating the need for 16 connections between LCD (104A) and Arduino). In other embodiment of the present invention the controller (102) in connected to the output device (104a,104b) by means of a USB interface.

[0014] The device has the capability to be connected to a PC and with an appropriate software the output from the device can be logged in the PC and can be extended to any compatible data acquisition system. This data logging capability can be extended to a cloud-based system by enabling a Wi-Fi feature in controller (102). Therefore, it can be considered an IOT device and which can then be integrated into any type of IOT system or a Cloud-based service. If a web-based cloud service is enabled, then the data can be sent to any centralized data management system where data from various tools can be collected and inferences shall be derived. The data transmission can be done by a GSM (Global System for Mobile communications) (4G or 5G) integrated with the controller (102). Apart from enabling a web-based service, the device also has a Bluetooth feature.

[0015] Figure 3 illustrates method steps for testing a sensor (106). A person skilled in the art would appreciate method steps described hereinafter are in context of the embodiments of the present invention described in accordance with figure 1 and 2. The sensor (106) is placed inside an aqueous solution tank and configured to measure a fill level, quality and at least a temperature value of the liquid or the aqueous solution. In an exemplary embodiment of the present invention, the sensor (106) being tested using the device herein disclosed is a Diesel Exhaust Fluid (DEF) tank sensor (106), the sensor uses PWM as the communication protocol wherein encoding and decoding corresponds to multiplexing and demultiplexing respectively.

[0016] In Method step 201, an electrical connector transmits a communication protocol (for example a pulse width modulating (PWM)) signal generated by the sensor (106) to a controller (102). The sensor (106) generates an encoded (multiplexed) signal as a result of the multiple information carried by the signal (multiplexed PWM signal). The features of the electrical connector and the controller (102) have been elucidated in accordance with figure 2. In method step 202, the controller (102) decodes (demultiplexes) the received encoded communication protocol (multiplexed PWM) signals. In case of multiplexed PWM signal, this is done to get values of widths of the pulses in PWM. Figure 4 illustrates the PWM signals received by the controller (102).

[0017] Method step 203 comprises calculating the values of fill level, quality and at least temperature based on the decoded information in the communication protocol signals (demultiplexed PWM). In case of the demultiplexed PWM formulas that take into account the information regarding the widths of pulses obtained in the demultiplexed PWM. Method step 204 comprises communicating the values of fill level, quality and at least temperature to an output device (104a,104b). The output device (104a,104b) has been elucidated above and can be any one or more from the group of but not limited to an LCD (104A) display screen, any HMI interface, a computer, a mobile phone or any network device. The output device (104a,104b) exhibits the value of fill level, quality and at least temperature.

[0018] It should be understood at the outset that, although exemplary embodiments are illustrated in the figures and described below, the present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the drawings and described below.This idea to develop a quick check module for detecting the errors helps identify a fault in the sensor (106) at any point in production phase (before assembly into the vehicle) and also in post-production (During the assembly into the vehicle/ during vehicle service). This aims to eliminate the large turnaround time required for analysis and avoid increased logistics time, cost and expensive product recalls. Further the device is designed in such a way that it can be used by anyone, even without the knowledge of working principle behind the sensor (106).

[0019] It must be understood that the embodiments explained in the above detailed description are only illustrative and do not limit the scope of this invention. Any modification to the device for testing a sensor (106) and a method thereof are envisaged and form a part of this invention. The scope of this invention is limited only by the claims.