Claims:We claim:
1. A device (100) for calibrating an Engine Control Unit (ECU) (102) of a vehicle (124) in a dynamometer (104), comprising:
a housing (108);
a plurality of actuators (122) located in said housing (108), and
an interface module (110) in said housing (108), said interface module (110) adapted to connect said plurality of actuators (122), said ECU (102) and said dynamometer (104) with a controller (120).

2. The device (100) as claimed in claim 1, wherein said plurality of actuators (122) are at least two selected from a group comprising a throttle actuator (112), a gear actuator (114), a clutch actuator (116), a brake actuator (118) and a fuel injection actuator.

3. The device (100) as claimed in claim 1, wherein said controller (120) is adapted to control a throttle position, a gear position, a clutch, a brake, a roller speed of said dynamometer (104), a blower speed of said dynamometer (104), a vehicle ignition, a vehicle kill switch and the like.

4. The device (100) as claimed in claim 1, wherein said controller (120) is connected to said interface module (110) through a wired or wireless communication channel.

5. The device (100) as claimed in claim 1, wherein said controller (120) communicates with said ECU (102) through a Controller Area Network (CAN) bus.

6. The device (100) as claimed in claim 1, wherein said controller (120) is external to said device (100) and is at least one of a local computer, a remote computer, a server and a handheld communication device.

7. The device (100) as claimed in claim 1, wherein said controller (120) is internal to said device (100) and is connected externally to at least one of a local computer, a remote computer, a server and a handheld communication device.

8. The device (100) as claimed in claim 1, wherein said controller (120) is adapted to operate said plurality of actuators (122) and said dynamometer (104) to calibrate said ECU (102) of said vehicle (124) based on a pre-stored calibration data.

9. The device (100) as claimed in claim 1, wherein said device (100) is portable and provided with casters (126).

10. The device (100) as claimed in claim 1, wherein said controller (120) is also adapted to run said vehicle (124) at desired drive cycles.
, 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 invention relates to a device for calibrating an Engine Control Unit (ECU) of a vehicle in a dynamometer.

Background of the invention:
[0002] With the introduction of tighter emission norms, electronics based EMS (Engine Management Systems) will proliferate across all segments. This demands for complex control functions in EMS, thus posing a huge challenge in development and calibration. Additionally, this needs to be achieved in a short time frame and limited resources; without compromising on quality. A typical single cylinder two wheeler EMS software contains approximately 700 parameters. This takes approximately 600 hours of calibration at test bench and additional time for on-road calibration. It includes trial and error methods which is iterative, hence the quality of output depends on the expertise of the calibration engineer.

[0003] Presently most of the calibration activities in the chassis dynamometer is done manually. The engineer has to manually adjust the throttle position, gear, dyno speed, blower speed and other tools continuously during the calibration. It requires a lot of test iterations which results in increased development time and cost. The quality of the data depends on the expertise of the engineer. It requires a lot of effort for verification of calibration and preparation of the report. Most of the process have to be repeated if any improvement is required.

[0004] Hence, there is a need for a solution to ease the calibration of ECUs in less time.

Brief description of the accompanying drawings:
[0005] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0006] Fig. 1 illustrates a device to calibrate an Engine Control Unit (ECU) of a vehicle, according to an embodiment of the present invention.

Detailed description of the embodiments:
[0007] Fig. 1 illustrates a device to calibrate an Engine Control Unit (ECU) of a vehicle, according to an embodiment of the present invention. The device 100 for calibrating the ECU 102 of the vehicle 124 is implemented in a dynamometer 104, specifically a chassis dynamometer 104. However, the device 100 is adaptable to an engine dynamometer 104 as well. The device 100 comprises a housing 108. A plurality of actuators 122 are located in the housing 108. An interface module 110 is also provided in the housing 108. The interface module 110 is adapted to connect the plurality of actuators 122, the ECU 102 and the dynamometer 104 with a controller 120. The ECU 102 is also referred to as an Engine Management System (EMS), and is shown outside the vehicle 124 for the convenience of explanation. The dynamometer 104 is controlled by respective control module 106.

[0008] The plurality of actuators 122 in the device 100 are at least two selected from a group comprising a throttle actuator 112, a gear actuator 114, a clutch actuator 116, a brake actuator 118 and a fuel injection actuator (not shown). Only the necessary components of the device 100 are shown and explained which must not be understood in the limiting manner. Such as power supply cable and corresponding circuits, and other components are omitted for the sake of simplicity.

[0009] The controller 120 is adapted to control a throttle position, a gear position, a clutch position, a brake actuation, a roller speed of the dynamometer 104, a blower speed of the dynamometer 104, a vehicle ignition, a vehicle kill switch and the like. The controller 120 is connected to the interface module 110 through a wired or wireless communication channel as known in the art.

[0010] The controller 120 communicates with the ECU 102 through a Controller Area Network (CAN) bus/channel of the vehicle 124 via the interface module 110.

[0011] In accordance to an embodiment of the present invention, the controller 120 is external to the device 100 and is at least one of a local computer, a remote computer, a server and a handheld communication device such as a smart phone. The controller 120 is adapted to operate the plurality of actuators 122 and the dynamometer 104 to calibrate the ECU 102 of the vehicle 124 based on a calibration data. The calibration data is pre-stored in the controller 120. The controller 120 operates the device 100 to calibrate the ECU 102 of the vehicle 124.

[0012] In an alternative embodiment, the controller 120 is internal to the device 100 and is connected externally to at least one of a local computer, a remote computer, a server and a handheld communication device. The controller 120 is a microcontroller with necessary components comprising a processor, input/ output interface, memory elements, communication units, Analog-to-Digital Converter (ADC) and/or Digital-to-Analog converter (DAC), and the like. The controller 120 is loaded with programs or logics based on the calibration data via external communication. The controller 120 then operates the device 100 through the interface module 110.

[0013] In accordance to an embodiment, the device 100 is portable and provided with casters 126. The casters 126 enables free movement of the device 100 across the dynamometer 104. The controller 120 is also adapted to run the vehicle 124 in a desired drive cycle.

[0014] According to the present invention, a working of the device 100 is described. The plurality of the actuators 122 are in closed loop communication with signals measured by the ECU 102 from the sensors installed in the vehicle 124 such as Manifold Air Pressure (MAP) sensor, a temperature sensor, an oxygen sensor, a throttle position sensor, a crankshaft position sensor and the like. The communication between the device 100 and ECU 102 is performed by CAN channel of the vehicle 124. However, other communications channels, as known in the art, are equally possible to be used for communicating with the ECU 102 or the sensors of the vehicle 124. The device 100 automates calibration of EMS or the ECU 102 of the vehicle 124 on the dynamometer 104. The device 100 is operated by the controller 120. The controller 120 is connected to the interface module 110 through a port such as Universal Serial Bus (USB) or an Ethernet port or other similar input/output port. The controller 120 communicates with the ECU 102 through the interface module 110. This interface module 110 communicates to the ECU 102 via CAN. The plurality of actuators 122 are interfaced or connected to the throttle, clutch, break and gear and other required controllable parts of the vehicle 124. The plurality of actuators 122 are also equipped with CAN modules. The plurality of actuators 122 are controlled by the interface module 110 via a separate CAN channel. The interface module 110 generally comprises plurality of CAN channel or ports for communication. One channel is connected to the vehicle CAN channel for calibration of the ECU 102. The other CAN channel is used control the plurality of actuators 122. Each actuator of the plurality of actuators 122 is controlled by unique CAN IDs. The dynamometer 104 is also controlled by the device 100 through a control module 106, again via CAN channel of the interface module 110. As the calibration continues, the plurality of actuators 122 are automatically controlled to bring the vehicle 124 to the desired operating point. The signals for air-fuel ratio or lambda, fuel flow, air flow and various temperatures etc. are measured by respective sensors installed in the vehicle 124, via the ECU 102.

[0015] In the device 100, the plurality of actuators 122 comprises stepper motors. The desired resolution in position setting is achieved by driving the stepper motor using micro stepping drivers. These motors are linked to the vehicle 124 using Bowden cables. In case of fuel injection actuator, the solenoid coil is directly supplied with the necessary electric power supply.

[0016] The dynamometer 104 parts such as a blower and rollers are controlled by analog voltage. This is a universal method for controlling the speed. Other controls of the switches on the vehicle 124 are done by relays. For various calibration requirements, predefined CAN messages are sent to each of the pluralities of actuators 122 by the controller 120. The dynamometer 104 is controlled either directly by the controller 120 or through the interface module 110 (via CAN channel or other communication channel).

[0017] In accordance to an embodiment of the present invention, the controller 120 is enabled with self-learning of the position and auto correction of the plurality of actuators 122. When one of the plurality of actuators 122 is powered ON, the controller 120 drives the control motor and learns the minimum and maximum position. For example, the throttle actuator 112 is moved from 0% to 100% and back to 0%. The controller 120 learns how many steps are required for the rotating the throttle of the vehicle 124 and the consistency of the throttle. Once the learning is done, the controller 120 is enabled to operate the throttle actuator 112 without a feedback from the ECU 102, thereby making the actuation and calibration very fast.

[0018] According to an embodiment of the present invention, an example of calibrating air flow characteristics of throttle valve to the ECU 102 is provided. A map 128 for estimating real mass flow over throttle valve is considered. An X-axis of the map 128 is percentage of throttle position and Y-axis is engine speed. The map 128 is stored as a table in a memory element of the controller 120. To calibrate the ECU 102 with the map 128, the vehicle 124 is brought to each X, Y point by controlling the throttle and the engine speed in the following manner. The throttle actuator 112 is operated to get the desired throttle position. The value of the Throttle Position Sensor (TPS) is read from the ECU 102 for a closed loop control. Then the dynamometer 104 is controlled to bring the vehicle 124 to the target engine speed. The engine speed is read from the ECU 102 as well. Also, the engine temperature is monitored. If the temperature is out of range, then the blower is switched ON to control the engine temperature.

[0019] The ECU 102 is further calibrated by checking the value of lambda or airflow or fuel flow values. The sensor values are sampled and the deviation are measured. Based on the deviation, a proper value of the map 128 is calculated and inserted followed by any fine adjustments. Then a next X, Y position is selected from the map 128 and the calibration is continued. Once all the points in the map 128 are finished, then all the grid points are verified and if a deviation is found, that is corrected. The calibration data is configurable as per the requirement. The device 100 is also possible to be operated from a remote location through different communication networks. Thus, the map 128 is calibrated inside the ECU 102 of the vehicle 124.

[0020] In accordance to an embodiment of the present invention, the controller 120 is adapted to generate reports or communicate status of an ongoing calibration and a completed calibration. The measurements, calibration are recorded and report is also generated automatically. The report is sharable with a concerned person. The device 100 is adaptable to be used for calibration of different types of vehicles 124 such as motorcycles, scooters, moped, auto-rickshaws, cars, buses, snow mobiles, jet skis and the like.

[0021] According to an embodiment of the present invention, the device 100 is a hardware which automates end-to-end calibration of the ECU 102. The device 100 makes the calibration process independent of expertise of a human calibration engineer. The device 100 automates the calibration, measurement and verification activities for the ECU 102 of the vehicle 124 without iterations that results in high reproducibility and less time and development cost. The device 100 is able to produce quality data in reduced time. The device 100 is also usable for driving different drive cycles on the dynamometer 104. This device 100 replaces the all the manual interventions needed for a calibration. The device 100 controls throttle position, gear, clutch, brake, roller speed of dynamometer 104, blower speed of the dynamometer 104 and the controls on the vehicle 124 such as ignition key, kill switch and the like.

[0022] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.