Electric diagram for robust signal processing
The invention relates to processing signals from sensors (D), in particular, detonation combustion. Electric diagram for robust signal processing allows to process output signals from D, for each D you must have two entrances. When processing the same signal with the reference potential "mass" for each D needs only one input. Signal processing is carried out in accordance with the differential circuitry, and in connection with a potential "mass" of the differential signal processing is performed using the generated by the circuit of the reference voltage. The mode of operation of this scheme, you can freely choose from the outside, using prescribed in the scheme of managing withdrawal. 5 C.p. f-crystals, 1 Il. The invention relates to a scheme for robust signal processing and first output signals of the sensors detonation combustion according to the restrictive part of the main claim.The prior art In the known solutions of the signals transmitted, for example, from the sensor to the processing unit for connecting the sensor and the processing unit shielded lines respectively to the wire. Such a display line is associated with relatively high costs it however does not guarantee full protection of the signal from distortion.For this reason, in DE-OS 4222475 proposed scheme that allows to damp the spurious signals in the signal lines, providing the opportunity to handle original undistorted signal. In this known circuit, the source signal as it is passed through the first signal line, and after inverting differentiation, respectively pass through the second signal line. At the end of the signal line initially inverted, respectively differentiated signal again invert, respectively integrate. Then this signal together with the transferred without change signal is passed through the valve And to deliver the output of the last original undistorted signal. When the connection cable between the sensor and the processing circuit also passes the trailing ground wire, it is possible to additionally provide protection against overvoltage, if between signal lines and ground to set the semiconductor Zener diodes.Advantages of the invention, the Advantage of the proposed invention is an electrical scheme for robust signal processing to the distinctive features of p. 1 claims on travcoa noise immunity of the signal processing in the almost complete elimination of common mode noise. This merit is achieved by performing the signal processing unit in accordance with a differential circuitry using technology with switchable capacitors. A particular advantage consists in the possibility to choose both symmetric and asymmetric mode of operation of the processing circuit, i.e. the possibilities of joining this scheme, sensors, outstanding to be processed signals, which allows unbalanced to connect them with the connections to the potential masses", as in symmetric mode without connection to the potential. The advantage of this choice of mode of operation allows the use of the proposed invention is an electric circuit for processing signals from conventional sensors, such as sensors detonation combustion shielded connecting wires and sensors with unshielded wires (twisted pair). This technical solution involving the use of the proposed electric circuit in combination with sensors, for example sensors detonation combustion with unshielded wires, has special advantages, since it allows low-cost to implement however.A special advantage of the proposed electric circuit is to set the desired mode of operation from the outside. Thus, in particular, the operation mode can be set, for example, by programming via the control pin is used to connect an external control circuits. Thus, the signal processing unit from the outside can be adapted to the desired requirements, i.e. to work in symmetric or asymmetric mode, connecting, for example, if there are four signal inputs or four sensor asymmetrically, i.e. over a potential "mass", or two sensors symmetrically, i.e. without connection to a potential "mass".Other advantages of the invention and preferred ways of its implementation are presented in the dependent claims.The drawing Below the invention is explained in more detail on the example of one of the variants of its implementation with reference to the drawing.The description of the exemplary embodiment In the drawing as the example shows one of the embodiments proposed in the invention of the electric circuit, which should be processing the output signals from the sensor K1 detonation combustion. This sensor K1 has two connection terminals A1, A2, whom he podsuna chain of communication. This passive circuit connection is formed by a capacitor CL connected between the connecting terminals A1, A2 of the sensor K1, and two parallel connected capacitors CA and Sa. Between these two capacitors included resistors R1b and R2b. In addition, the capacitor CA through resistor R1a is connected to the input E1 and the capacitor CA through the resistor R2a is connected to the input E2 of the circuit's signal transformation to the normalized mean. Both resistor R1b and R2b is connected to the input of the reference voltage to which the applied voltage Ur.In the schema S is a differential input amplifier V is connected to the two inputs E1 and E2. For the amplifier V series not shown in the drawing, the cascades of signal transformation to the normalized mind having, for example, at least one bandpass filter, and/or one rectifier, and/or one integrator and is made, for example, in accordance with the differential circuitry.To these cascades conversion signals connected output stage And that can convert the differential signal to a single-ended signal with a reference potential "mass" and send it via analog-to-digital Converter microcomputer (MC) for further processing.
th combustion connected, for example, a twisted pair connection potential with the two inputs E1, E2 circuit S conversion signals normalized to mind. Input cascade this scheme conversion to suppress common mode noise is made in the form of a differential amplifier cascade, in particular in the form of "amplifier with switchable capacitors with multi-stage gain control. Enabled him cascades of signal transformation to the normalized mean can also be made in accordance with the differential circuitry. This applies, in particular, bandpass filters, rectifiers or integrators. Such a scheme could be implemented using technology with switchable capacitors allows you to inexpensively and compactly integrate the necessary analog functions in semiconductor processors, for example, according to the technology of high-quality CMOS IC.The fact that the output stage circuit signal transformation to the normalized mean can convert the differential signal to a single-ended signal with a reference potential "mass" coming eventually in the microcomputer can be used for various signal processing approach. For example, in the recognition system detones which are respectively connected to two inputs of the circuit signal transformation to the normalized mean these two sensors can be attached symmetrically, i.e. without connection to the potential. In this arrangement, activation of the sensor signals in this mode are solely differential processing.When using the same schema conversion signals normalized to mind with four inputs that can process signals up to four sensors, select single-ended mode of operation in which the sensors detonation combustion is connected to the mapping signals to the normalized mean by connecting to your potential "mass". In this mode generated in the mapping signals normalized to mean a stable (fixed) reference voltage Ur is used as reference voltage for differential signal processing.The presence in the circuit of the signal transformation to the normalized mean additional control output for external control circuits allows using this control output, external to program the appropriate operating mode. Thus, it is possible from the outside to select a specific mode, which allows for a constant number of inputs and using the same scheme of signal transformation to the normalized type of connection connection to a potential "mass" and to produce the appropriate signal processing in a particular mode.By selecting one or the other operating mode, the sensors can be connected to the signal processing unit or unshielded wires twisted pair or shielded connecting cables. Electrical circuit that can be made in the form of a corresponding chip signal processing, in combination with unshielded wire sensors detonation combustion allows to implement simple, inexpensive and yet robust system for determining detonation knock in the engine. Although in the above example we were talking about the processing of signals from sensors detonation combustion, however, the scope of the proposed invention the electric circuit is not limited to processing signals from these sensors detonation combustion, and this scheme can also be used for processing signals from sensors of a different type and purpose.
Claims1. The electrical circuit for error-correcting processing of the output signals of at least one sensor having a mapping signals normalized to mind, having at least two inputs to which are connected the same is connected with the specified inputs of a differential amplifier and an output stage, if necessary, transforming issued differential amplifier the differential signal into a signal with a reference potential "mass", characterized in that it is configured to work in two modes, the first of which is used to connect without connecting to the potential of obtaining a symmetrical signal, and the second is used when connecting with connecting to a reference potential by receiving a single-ended signal, while the opportunity is provided externally programmable via the control output select one of the modes and thereby switch between modes with obtaining balanced and unbalanced signals.2. The diagram on p. 1, characterized in that between the sensor or sensors and the actual mapping signals normalized to mind included passive circuit connection.3. The diagram on p. 2, wherein the passive circuit connection is made symmetric and has one first capacitor (CL) connected between the terminals of the sensor, and the other two capacitor (CA, Sa), which on the one hand connected to the sensor, and on the other hand through the resistors (R1a, R2a) are connected with the inputs El, E2) of the scheme (S) converting signals normalized to mind, and through resi is tives such as those what a differential amplifier (V) sequentially enabled cascades of signal processing, in particular at least one bandpass filter and/or at least one rectifier, and/or at least one integrator.5. The circuit according to any one of paragraphs.1-4, characterized in that the output stage (A) of the scheme (S) converting signals normalized to mind through analog-to-digital Converter connected to the microcomputer, and signal processing is carried out in the specified microcomputer.6. The circuit according to any one of paragraphs.1-5, characterized in that it is designed for processing output signals of the two sensors detonation combustion, which unshielded wires connected without connecting to the potential for each pair of input circuits signal transformation to the normalized mind, or is intended for processing output signals of the four sensors detonation combustion, which shielded wires are connected respectively to one input circuit of the signal transformation to the normalized mean.