Multifunctional control integrated circuit for seat

Abstract

This utility model provides a multi-functional control integrated circuit for a seat. This circuit implements a low-power sleep mode, allowing the seat to enter a sleep state when not in use, reducing battery power consumption. This circuit also implements a reverse connection protection method for the battery, automatically shutting off the circuit when the positive and negative terminals of the battery are reversed, thus protecting the circuit. Furthermore, this circuit implements a motor drive method, enabling the motor to operate, monitoring the motor current in real time, and monitoring the motor's operating and fault status, allowing the motor to enter sleep mode based on the fault status. Finally, this circuit implements a motor Hall voltage sampling method, using a Hall level conversion circuit to sample the number of motor pulses, thereby controlling the motor's start / stop position information.

Description

Technical Field

[0001] This utility model belongs to the field of automotive seat integrated circuit technology, and particularly relates to a multi-functional control integrated circuit for seats. Background Technology

[0002] With the increasing popularity of automobiles, consumers have higher and higher demands. Besides price, people are paying more attention to vehicle safety and comfort. Car seats are not only key to improving passenger comfort, but also crucial technologies for developing high-quality car seats and establishing market competitiveness. This invention designs an integrated circuit for multi-functional seat control, capable of realizing a multi-functional control system including seat motor control, massage control, and heating control. Utility Model Content

[0003] This invention provides a multi-functional control integrated circuit for seats, which aims to solve the problems mentioned in the background art.

[0004] This utility model is implemented as follows: a multi-functional control integrated circuit for a seat includes a power reverse connection protection unit, an LDO voltage conversion and sleep unit, an MCU control unit, a motor drive protection unit, a motor pulse voltage sampling unit, a heating and massage fan control unit, and a temperature detection unit.

[0005] The power supply reverse connection protection unit includes two MOSFETs and is used for reverse connection protection.

[0006] The LDO voltage conversion and sleep unit includes a 5V voltage conversion circuit and a 3.3V voltage conversion circuit. The 5V voltage conversion circuit converts 12V voltage to 5V voltage through a step-down chip, and the 3.3V voltage conversion circuit converts 12V voltage to 3.3V voltage through a step-down chip.

[0007] The MCU control unit includes a 3.3V power supply filter circuit, a crystal oscillator circuit, a battery voltage acquisition circuit, an MCU main control circuit, and a communication circuit. The 3.3V power supply filter circuit provides a stable and reliable 3.3V power supply to the MCU. The battery voltage acquisition circuit is used to detect the input battery voltage. The crystal oscillator circuit is used to provide a stable clock signal for the MCU to operate. The MCU main control circuit is used to output a PWM pulse width wave to drive the motor. The communication circuit consists of a LIN communication circuit.

[0008] The motor drive protection unit includes a main control drive chip and an overcurrent / fault detection circuit. The main control drive chip consists of two half-bridge drive chips forming a full-bridge motor circuit. The MCU controls the two half-bridge drive chips to control the conduction of the upper and lower transistors of the full-bridge circuit, thereby controlling the forward and reverse rotation of the seat motor. The overcurrent / fault detection circuit is used for motor overcurrent protection and motor fault detection.

[0009] The motor pulse voltage sampling unit is used to sample the Hall sensor voltage of the motor;

[0010] The heating and massage fan control unit includes a heating control circuit, a massage control circuit, and a fan control circuit. The heating control circuit controls the heating and shutting off of the heating pad. The massage control circuit controls the opening and closing of the massage solenoid valve within a unit of time to control the inflation and deflation of the massage air bag within a unit of time. The fan control circuit controls the power and high / low wind speed of the fan.

[0011] The temperature detection unit includes two thermistors, the resistance of which changes with temperature.

[0012] Preferably, in the power reverse connection protection unit, when the positive terminal of the power supply is connected to the KL-30 terminal interface and the negative terminal is connected to GND, the MOSFET is turned on and outputs VIN-12V; when the positive terminal of the power supply is connected to GND and the negative terminal is connected to KL-30, the MOSFET is turned off and there is no VIN-12V output.

[0013] Preferably, the 3.3V power supply filtering circuit includes an LC low-pass filter, which filters out AC interference signals from the 3.3V voltage carrying interference signals, turning it into a clean 3.3V voltage.

[0014] Preferably, the battery voltage acquisition circuit includes two voltage divider resistors, which divide the battery sampling voltage.

[0015] Preferably, the communication circuit is used for communication between the host computer and the seat MCU.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. This circuit implements a low-power sleep mode, which allows the seat to enter a sleep state when it is not in use, thereby reducing battery power consumption;

[0018] 2. This circuit implements a method to prevent reverse connection of the battery, which can automatically shut off the circuit when the positive and negative terminals of the battery input are reversed, thereby protecting the circuit.

[0019] 3. This circuit implements a motor drive method. Through the motor drive circuit, the motor can be driven to work, the motor current can be monitored in real time, the motor working and fault status can be monitored in real time, and the motor can be put into sleep mode in real time according to the motor fault status.

[0020] 4. This circuit implements a motor Hall voltage sampling method. It uses a Hall level conversion circuit to sample the number of motor pulses, thereby controlling the start and stop position information of the motor. Attached Figure Description

[0021] Figure 1 This is the circuit diagram of the reverse polarity protection unit in this utility model;

[0022] Figure 2 This is a circuit diagram of the 5V voltage conversion in this utility model;

[0023] Figure 3 This is a circuit diagram of the 3.3V voltage conversion in this utility model;

[0024] Figure 4 This is a circuit diagram of the 3.3V power supply filter in this utility model;

[0025] Figure 5 This is a circuit diagram of the battery voltage detection circuit in this utility model;

[0026] Figure 6 This is the crystal oscillator circuit diagram in this utility model;

[0027] Figure 7 This is a communication circuit diagram of the present invention;

[0028] Figure 8 This is a circuit diagram of the main control driver chip in this utility model;

[0029] Figure 9 This is a circuit diagram of the overcurrent / fault detection circuit in this utility model;

[0030] Figure 10 This is a circuit diagram of the motor pulse voltage sampling unit in this utility model;

[0031] Figure 11 This is a circuit diagram of the heating control system in this utility model;

[0032] Figure 12 This is a circuit diagram of the massage control system in this utility model;

[0033] Figure 13 This is a circuit diagram of the fan control system in this utility model;

[0034] Figure 14 This is the circuit diagram of the temperature detection unit in this utility model. Detailed Implementation

[0035] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0036] The components of the present invention embodiments described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0037] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0038] Please see Figures 1 to 14 This utility model provides a technical solution: a multi-functional control integrated circuit for a seat, including a power reverse connection protection unit, an LDO voltage conversion and sleep unit, an MCU control unit, a motor drive protection unit, a motor pulse voltage sampling unit, a heating and massage fan control unit, and a temperature detection unit;

[0039] The power supply reverse connection protection unit includes two MOSFETs and is used for reverse connection protection. The LDO voltage conversion and sleep unit includes a 5V voltage conversion circuit and a 3.3V voltage conversion circuit. The 5V voltage conversion circuit converts 12V to 5V using a step-down chip, and the 3.3V voltage conversion circuit converts 12V to 3.3V using a step-down chip. The MCU control unit includes a 3.3V power supply filter circuit, a crystal oscillator circuit, a battery voltage acquisition circuit, an MCU main control circuit, and a communication circuit. The 3.3V power supply filter circuit provides a stable and reliable 3.3V power supply to the MCU. The battery voltage acquisition circuit detects the input battery voltage. The crystal oscillator circuit provides a stable clock signal for the MCU. The MCU main control circuit outputs a PWM pulse width waveform to drive the motor. The communication circuit consists of a LIN communication circuit. The motor drive protection unit... The unit includes a main control driver chip and an overcurrent / fault detection circuit. The main control driver chip consists of two half-bridge driver chips forming a full-bridge motor circuit. The MCU controls the two half-bridge driver chips to control the conduction of the upper and lower transistors of the full-bridge circuit, thereby controlling the forward and reverse rotation of the seat motor. The overcurrent / fault detection circuit is used for motor overcurrent protection and motor fault detection. The motor pulse voltage sampling unit is used to sample the Hall sensor voltage of the motor. The heating and massage fan control unit includes a heating control circuit, a massage control circuit, and a fan control circuit. The heating control circuit controls the heating and shutting off of the heating pad. The massage control circuit controls the opening and closing of the massage solenoid valve per unit time to control the inflation and deflation of the massage airbag per unit time. The fan control circuit controls the power and high / low wind speed of the fan. The temperature detection unit includes two thermistors, whose resistance changes with temperature.

[0040] In this embodiment, refer to Figure 1The reverse connection protection unit mainly consists of two P-channel MOSFETs, Q1 and Q2. When the positive terminal of the power supply is connected to the KL-30 terminal and the negative terminal is connected to GND, the P-channel MOSFET is turned on and outputs VIN-12V. When the power supply is reversed, i.e., the positive terminal is connected to GND and the negative terminal is connected to KL-30, the P-channel MOSFET is turned off and there is no VIN-12V output. At this time, the circuit of the reverse connection protection unit plays the role of reverse connection protection.

[0041] See Figure 2 and Figure 3 The LDO voltage conversion and sleep unit mainly includes a 5V voltage conversion circuit and a 3.3V voltage conversion circuit;

[0042] See Figure 2 The 5V voltage conversion circuit control method is as follows: 12V voltage (input at port VIN-12) is converted into 5V power supply through a step-down chip (U4: SA21345FCA). The ADJ pin of the U4 chip controls the output voltage value, and the EN pin controls the chip's wake-up and sleep modes. Specifically, EN is pulled down by resistor R60 to make the EN pin less than 0.4V, at which point U4 is in sleep mode. When wake-up is required, the MCU outputs a high level, making the EN pin greater than 1.5V, at which point U4 is in wake-up mode and outputs 5V voltage.

[0043] See Figure 3 The control method for the 3.3V voltage conversion circuit is as follows: 12V voltage (input at port VIN-12) is converted into 3.3V power supply through a step-down chip (U4: SA21340FCA). The ADJ pin of the U21 chip controls the output voltage value, and the EN pin controls the chip's wake-up and sleep modes. Specifically, EN is pulled down by resistor R225 to make the EN pin voltage less than 0.4V, at which point U4 is in sleep mode. When wake-up is required, the button KEY or CAN-INH outputs a high level, making the EN pin voltage greater than 1.5V. At this time, U4 is in wake-up mode and outputs 3.3V voltage.

[0044] See Figures 4 to 7 The circuit of the MCU control unit includes a 3.3V power supply filter circuit, a crystal oscillator circuit, a battery voltage acquisition circuit, an MCU main control circuit, and a communication circuit.

[0045] See Figure 4The 3.3V power supply filter circuit mainly provides a stable and reliable 3.3V power supply for the MCU. Its operation is as follows: After the 3.3V voltage output from U4 passes through an LC low-pass filter composed of inductor L2 and capacitors C54 and C170. The 3.3V voltage carrying interference signals is filtered out by the LC low-pass filter, eliminating AC interference signals and resulting in a clean 3.3V voltage. The principle is that most of the AC interference signal is blocked and absorbed by inductor L2, becoming magnetic induction and heat energy. The remaining majority is bypassed to ground by capacitors C54 and C170. This suppresses the effect of interference signals, resulting in a relatively pure 3.3V DC voltage at the output.

[0046] See Figure 5 The battery voltage detection circuit mainly detects the input battery voltage and works as follows: the sampled battery voltage is divided by voltage divider resistors R255 and R256. The divided voltage is given to the ADC voltage sampling port of the MCU. When the voltage is too low or too high, the MCU shuts off the output of the seat drive motor chip, thereby shutting off the motor.

[0047] See Figure 6 The crystal oscillator circuit mainly provides a stable clock signal for the MCU to work, ensuring the reliable clock signal required for the microcontroller to operate. The operation is as follows: the crystal oscillator is based on the piezoelectric effect, that is, when an electric field is applied to the electrodes of the crystal, the crystal will produce mechanical deformation, and vice versa; when an alternating voltage is applied, the crystal will produce mechanical vibration, thereby generating a stable clock signal.

[0048] The MCU main control circuit is mainly used for outputting PWM pulse width waveforms to drive the motor, voltage detection, current detection, switch button control output, and communication.

[0049] See Figure 7 The communication circuit consists of a LIN communication circuit. The communication part mainly involves communication between the host computer (or vehicle unit) and the seat MCU. The seat's working status or fault information is communicated to the host computer (or vehicle unit) through the LIN communication circuit. The host computer (or vehicle unit) can also adjust the seat's functions through the LIN communication circuit. The operation is as follows: The LIN bus uses single-wire transmission, the level is usually 12V, and the maximum transmission rate is 20kbps. Its network structure is a single master and multiple slave mode. A LIN network can connect up to 16 nodes. The master node (host computer or vehicle unit) is responsible for scheduling communication, monitoring data, and handling errors, while the slave nodes (seat motor control, massage control, heating control, and ventilation control, etc.) only respond or receive instructions after receiving the frame header from the master node.

[0050] See Figure 8 and Figure 9 The motor drive protection unit includes a main control drive chip and an overcurrent / fault detection circuit;

[0051] See Figure 8 The main control driver chip works as follows: The motor driver chip consists of two half-bridge driver chips U15 (IC-DRV8145SQRXZRQ1) and U16 (IC-DRV8145SQRXZRQ1) forming a full-bridge motor circuit. The MCU controls pins 3 (NSLEEP), 11 (DRVOFF), and 12 (IN) of U15 and U16 to control the conduction of the upper or lower tube of the full-bridge, thereby controlling the forward and reverse rotation of the seat motor.

[0052] See Figure 9 The overcurrent detection and fault detection circuit for the motor operates as follows: Overcurrent detection control method: Overcurrent is detected by comparing pin 2 (IPROPI) of U15 and U16 with the internal reference voltage of U15 and U16. Pin 2 mainly detects the current and voltage when the high-voltage upper transistor of U15 and U16 is turned on (pin 2 is connected to ground through a resistor R235, and the operating current flowing through R235 is converted into voltage (U=I*R)). By comparing pin 2 with the internal reference voltage, it is determined whether there is an overcurrent. If pin 2 is greater than the reference voltage, there is an overcurrent, the driver chip output is turned off, and the motor does not work (at the same time, pin 1 is pulled low, and a fault signal is reported, see the fault detection control method below); otherwise, it works normally.

[0053] Fault detection and control method: The fault signal is determined by the high or low level of pin 1 (NFAUL) of U15 and U16. NFAUL-1 is connected to pin 1 (NFAUL) of U15 and U16. The 3.3V pull-up voltage makes pin 1 of U15 and U16 high. The MCU detects that U15 and U16 are at a high level and determines that U15 and U16 are working normally. The MCU controls pins 3, 11, and 12 of U15 and U16 to make the motor work normally. When the motor has a fault such as overcurrent, the level of pin 1 of U15 and U16 is pulled low. The MCU detects that U15 and U16 are at a low level and determines that U15 and U16 are malfunctioning. The MCU controls pins 3, 11, and 12 of U15 and U16 to stop the motor.

[0054] See Figure 10The motor pulse sampling circuit primarily samples the Hall sensor voltage of the motor. When the motor rotates forward, the Hall sensor is at a high level, transistor Q7 is turned on, and the voltage sampled by the MCU's voltage sampling port MCU_HALL_1 is at a low level, with the MCU's internal pulse count being 0. When the Hall sensor is at a low level, transistor Q7 is not turned on, and the voltage sampled by the MCU's voltage sampling port MCU_HALL_1 is at a high level, increasing the MCU's internal pulse count by 1. This process repeats, with the MCU's internal pulse count increasing cumulatively for each time the Hall sensor is at a low level. When the motor rotates in reverse, the Hall sensor is at a high level, transistor Q7 is turned on, and the voltage sampled by the MCU's voltage sampling port MCU_HALL_1 is at a low level, with the MCU's internal pulse count being 0. When the Hall sensor is at a low level, transistor Q7 is not turned on, and the voltage sampled by the MCU's voltage sampling port MCU_HALL_1 is at a high level, decreasing the MCU's internal pulse count by 1. This process repeats, with the MCU's internal pulse count increasing or decreasing cumulatively for each time the Hall sensor is at a low level. The current position of the seat motor is adjusted by adding or subtracting the number of pulses;

[0055] See Figures 11 to 13 The heating and massage fan control unit mainly consists of a heating control circuit, a massage control circuit, and a fan control circuit;

[0056] See Figure 11 The heating control circuit uses the HEAT_PWM port to output high and low levels to adjust the on / off state of Q13. Specifically, when the output is high, transistor Q13 is turned on, and the gate (G) of MOSFET Q15 is low, so MOSFET Q15 is not turned on and the heating pad does not heat up. When the output is low, transistor Q13 is not turned on, and the gate (G) of MOSFET Q15 is high, so MOSFET Q15 is turned on and the heating pad heats up. This controls the on / off state of Q15, thus controlling the heating pad's start and stop.

[0057] See Figure 12 Massage control circuit: The MCU adjusts the opening and closing of Q17 by outputting high and low levels through the WAIST_PWM1 port, thereby controlling the opening and closing of Q19. Specifically: when the output is high, transistor Q17 is turned on, the gate of MOSFET Q19 is low, MOSFET Q19 is not turned on, the solenoid valve does not open, and the massage air bag is not inflated; when the output is low, transistor Q17 is not turned on, the gate of MOSFET Q19 is high, MOSFET Q19 is turned on, the solenoid valve opens, and the massage air bag is inflated, thereby controlling the opening and closing of the massage solenoid valve within a unit of time, and achieving the purpose of controlling the inflation and deflation of the massage air bag within a unit of time.

[0058] See Figure 13 The fan control circuit works as follows: The MCU outputs a PWM pulse width waveform through the FAN_PWM port to adjust the on and off state of Q14, thereby controlling the on and off state of Q16. The output power is adjusted by the PWM pulse width. Specifically: when the output PWM is high, transistor Q14 is turned on, and the gate of MOSFET Q15 is low, so MOSFET Q15 is not turned on and the fan does not work; when the output PWM is low, transistor Q14 is not turned on, and the gate of MOSFET Q15 is high, so MOSFET Q15 is turned on and the fan works. The MCU outputs PWM, with a conduction time of Ton within a period T. Therefore, the duty cycle is D = Ton / T. According to the formula Vout = D * Vin, when the input voltage Vin remains constant, changing the duty cycle D changes the output voltage Vout. Based on the power formula P = (U * U) / R, and considering the fan's internal resistance R, the power P = (Vout * Vout) / R. By adjusting the changing Vout, the fan power can be controlled, thus controlling the fan speed.

[0059] See Figure 14 The temperature detection unit mainly consists of thermistors R227 and R228. When the temperature changes, the resistance values ​​of R227 and R228 also change. For example, 25℃ corresponds to a resistance of 1K, 45℃ corresponds to a resistance of 3K, and 60℃ corresponds to a resistance of 5K. This changes the voltage output to the MCU ports NTC_AD1 and NTC_AD2. The MCU calculates that a certain voltage threshold indicates an over-temperature condition (for example, if 60℃ is set as an over-temperature condition, the resistance value corresponding to 60℃ is 5K. By dividing the 10K and 5K voltages at the upper end, the voltage at the MCU's ADC port is 1.1V (3.3V*5000Ω / (5000Ω+10000Ω)=1.1V). When the MCU's ADC port detects that the voltage is 1.1V, it shuts off the motor drive output, thus shutting off the motor output and preventing the motor from working.

[0060] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-functional control integrated circuit for a seat, characterized in that: It includes a power reverse connection protection unit, an LDO voltage conversion and sleep unit, an MCU control unit, a motor drive protection unit, a motor pulse voltage sampling unit, a heating and massage fan control unit, and a temperature detection unit; The power supply reverse connection protection unit includes two MOSFETs and is used for reverse connection protection. The LDO voltage conversion and sleep unit includes a 5V voltage conversion circuit and a 3.3V voltage conversion circuit. The 5V voltage conversion circuit converts 12V voltage to 5V voltage through a step-down chip, and the 3.3V voltage conversion circuit converts 12V voltage to 3.3V voltage through a step-down chip. The MCU control unit includes a 3.3V power supply filter circuit, a crystal oscillator circuit, a battery voltage acquisition circuit, an MCU main control circuit, and a communication circuit. The 3.3V power supply filter circuit provides a stable and reliable 3.3V power supply to the MCU. The battery voltage acquisition circuit is used to detect the input battery voltage. The crystal oscillator circuit is used to provide a stable clock signal for the MCU to operate. The MCU main control circuit is used to output a PWM pulse width wave to drive the motor. The communication circuit consists of a LIN communication circuit. The motor drive protection unit includes a main control drive chip and an overcurrent / fault detection circuit. The main control drive chip consists of two half-bridge drive chips forming a full-bridge motor circuit. The MCU controls the two half-bridge drive chips to control the conduction of the upper and lower transistors of the full-bridge circuit, thereby controlling the forward and reverse rotation of the seat motor. The overcurrent / fault detection circuit is used for motor overcurrent protection and motor fault detection. The motor pulse voltage sampling unit is used to sample the Hall sensor voltage of the motor; The heating and massage fan control unit includes a heating control circuit, a massage control circuit, and a fan control circuit. The heating control circuit controls the heating and shutting off of the heating pad. The massage control circuit controls the opening and closing of the massage solenoid valve within a unit of time to control the inflation and deflation of the massage air bag within a unit of time. The fan control circuit controls the power and high / low wind speed of the fan. The temperature detection unit includes two thermistors, the resistance of which changes with temperature.

2. The multi-functional control integrated circuit for a seat according to claim 1, characterized in that: In the power reverse connection protection unit, when the positive terminal of the power supply is connected to the KL-30 terminal interface and the negative terminal is connected to GND, the MOSFET is turned on and outputs VIN-12V; when the positive terminal of the power supply is connected to GND and the negative terminal is connected to KL-30, the MOSFET is turned off and there is no VIN-12V output.

3. The multi-functional control integrated circuit for a seat according to claim 1, characterized in that: The 3.3V power supply filtering circuit includes an LC low-pass filter, which filters out AC interference signals from the 3.3V voltage containing interference signals, turning it into a clean 3.3V voltage.

4. The multi-functional control integrated circuit for a seat according to claim 1, characterized in that: The battery voltage acquisition circuit includes two voltage divider resistors, which divide the battery sampling voltage.

5. The multi-functional control integrated circuit for a seat according to claim 1, characterized in that: The communication circuit is used for communication between the host computer and the seat MCU.

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