A weight detection circuit applied to an electric tricycle

Abstract

This utility model relates to the field of electric tricycle technology, and in particular to a load detection circuit for electric tricycles. It includes a microcontroller minimum system, a vehicle controller, a first pressure sensor, and a second pressure sensor. The vehicle controller is connected to the P18 pin of the main control MCU via a one-wire bus. Both the first and second pressure sensors are located inside the rear seat cushion. The detection terminal of the first pressure sensor inputs two signals to the P1.1 and P1.2 pins of the first pressure sensing chip, respectively. The DO pin of the first pressure sensing chip is connected to the P19 pin of the main control MCU. The detection terminal of the second pressure sensor inputs two signals to the P1.1 and P1.2 pins of the second pressure sensing chip, respectively. The DO pin of the second pressure sensing chip is connected to the P27 pin of the main control MCU. This utility model uses a combination of two sets of pressure sensors of different models, and by setting them in different positions, measures whether the rear seat is carrying a passenger and whether it is overloaded. The load status is monitored by inputting high and low levels to the main control MCU.

Description

Technical Field

[0001] This utility model relates to the field of electric tricycle technology, and in particular to a load detection circuit for electric tricycles. Background Technology

[0002] Electric tricycles are a common mode of transportation; however, the torque of currently available tricycles cannot be adjusted in real time according to consumer needs. When the vehicle is heavily loaded, the rated starting torque is low, resulting in insufficient power and difficulty starting, or even rolling backward. Furthermore, when consumers use recreational tricycles for hauling goods or other production purposes, the controller and motor operate under overload conditions for extended periods, leading to increased vehicle failure rates and reduced lifespan. Therefore, there is an urgent need for a solution to detect the load status of electric tricycles so that the controller can adjust the torque accordingly. Utility Model Content

[0003] The purpose of this invention is to address the problems existing in the background technology by proposing a load detection circuit for electric tricycles.

[0004] The technical solution of this utility model is a load detection circuit for electric tricycles, including a single-chip microcomputer minimum system, a vehicle controller, a first pressure sensor and a second pressure sensor.

[0005] The minimum system of a single-chip microcomputer includes a main control MCU, a power supply circuit, a reset circuit, and a crystal oscillator;

[0006] The vehicle controller is connected to the P18 pin of the main control MCU via a one-wire bus;

[0007] The first pressure sensor and the second pressure sensor are both located inside the rear seat cushion. The detection end of the first pressure sensor inputs two signals to the P1.1 and P1.2 pins of the first pressure sensing chip, respectively. The DO pin of the first pressure sensing chip is connected to the P19 pin of the main control MCU. The first pressure sensing chip is set with a start pressure. When the sensor is not under pressure or the pressure is less than the start pressure, it outputs a high level of 3.3V, and otherwise outputs a low level of 0V.

[0008] The detection end of the second pressure sensor inputs two signals to the P1.1 and P1.2 pins of the second pressure sensor chip respectively; the DO pin of the second pressure sensor chip is connected to the P27 pin of the main control MCU; the second pressure sensor chip sets the start pressure, and outputs a high level of 3.3V when the sensor is not under pressure or the pressure is less than the start pressure, and outputs a low level of 0V otherwise.

[0009] Preferably, the first pressure sensor is a thin-film resistive sensor.

[0010] Preferably, the starting pressure of the first pressure sensor is set to 25-30 kg.

[0011] Preferably, the second pressure sensor is a piezoelectric weighing sensor.

[0012] Preferably, the starting pressure of the second pressure sensor is set to 190-195 kg.

[0013] Preferably, the power supply circuit converts the 12V voltage to 3.3V voltage to power the microcontroller minimum system and the first and second pressure sensors.

[0014] Preferably, the power supply circuit includes an AMS1117 power chip; a 12V power supply is connected in series with a 10A fuse and a diode and then connected to the Vin terminal of the power chip; the output terminal of the power chip outputs a 3.3V voltage; the GND terminal of the power chip is grounded.

[0015] Two 10uF capacitors are connected in parallel between the output terminal of the diode and the ground terminal; two 10nF capacitors are connected in parallel between the output terminal of the power supply chip and the ground terminal.

[0016] Preferably, the vehicle controller adjusts the output current to control the motor torque.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] This invention combines two sets of pressure sensors of different models, which, by setting them in different positions, measure whether the rear seat is carrying passengers and whether it is overloaded. The load status is monitored by inputting high and low voltage levels to the main control MCU. Simultaneously, the two pressure sensors complement each other, reducing the chance of false alarms. This protects the efficiency of the motor and controller and allows for real-time torque adjustment based on the load weight. Attached Figure Description

[0019] Figure 1 This is a circuit diagram of the detection circuit in an embodiment of the present invention;

[0020] Figure 2 This is a power supply circuit diagram in an embodiment of the present invention. Detailed Implementation

[0021] Example 1

[0022] like Figure 1 As shown, the present invention proposes a load detection circuit for electric tricycles, including a single-chip microcomputer minimum system, a vehicle controller, a first pressure sensor, and a second pressure sensor.

[0023] The minimum system of a single-chip microcomputer includes a main control MCU, a power supply circuit, a reset circuit, and a crystal oscillator;

[0024] The vehicle controller is connected to the P18 pin of the main control MCU via a one-wire bus;

[0025] The first pressure sensor and the second pressure sensor are both located inside the rear seat cushion. The detection end of the first pressure sensor inputs two signals to the P1.1 and P1.2 pins of the first pressure sensing chip, respectively. The DO pin of the first pressure sensing chip is connected to the P19 pin of the main control MCU. The first pressure sensing chip is set with a start pressure. When the sensor is not under pressure or the pressure is less than the start pressure, it outputs a high level of 3.3V, and otherwise outputs a low level of 0V.

[0026] The second pressure sensor receives two signals at its detection end, which are respectively sent to pins P1.1 and P1.2 of the second pressure sensing chip. The DO pin of the second pressure sensing chip is connected to pin P27 of the main control MCU. The second pressure sensing chip is set with a start-up pressure; when the sensor is not under pressure or the pressure is less than the start-up pressure, it outputs a high level of 3.3V, and otherwise outputs a low level of 0V. In this embodiment, both the first and second pressure sensors are installed inside the second row of seats in the electric tricycle. The first pressure sensor is a thin-film resistive sensor, and its start-up pressure is set to 25-30kg. The second pressure sensor is a piezoelectric weighing sensor, and its start-up pressure is set to 190-195kg. The thin-film resistive sensor can be placed inside the foam padding of the seat to measure the load on the rear seat without affecting the riding experience, thus helping to determine whether a passenger is being carried. The piezoelectric weighing sensor can be installed inside the seat frame to easily weigh the total weight of the entire rear seat, avoiding any impact on riding comfort.

[0027] In this embodiment, as Figure 2 As shown, the power supply circuit converts 12V to 3.3V to power the microcontroller minimum system and the first and second pressure sensors. The power supply circuit includes an AMS1117 power chip; a 12V power supply connected in series with a 10A fuse and a diode is connected to the Vin terminal of the power chip; the power chip outputs 3.3V; the power chip's GND terminal is grounded; two 10uF capacitors are connected in parallel between the diode's output and ground; and two 10nF capacitors are also connected in parallel between the power chip's output and ground. The power supply circuit provides a standard 3.3V voltage to the entire detection circuit to facilitate the operation of each module.

[0028] In this embodiment, the vehicle controller adjusts the output current to control the motor torque. For example, when the first pressure sensor outputs a high level, the second pressure sensor will definitely output a high level; at this time, the tricycle has no load or a small load; the torque in the calibration mode can meet the actual needs. When the first pressure sensor outputs a low level and the second pressure sensor outputs a high level, it means the tricycle has a load, and the controller adjusts the bus current and motor speed to increase the torque. When both the first and second pressure sensors output low levels, the vehicle is overloaded, and the main control MCU transmits the vehicle load status to the controller via the One-Line Communication Protocol. The controller cannot deactivate the P gear and enters the automatic protection mode. In this embodiment, the FSR pressure sensor chip also includes a potentiometer for adjusting the threshold. The trigger threshold is changed by rotating the nut on the potentiometer. The starting pressure of the first pressure sensor is set to 25-30 kg, and the starting pressure of the second pressure sensor is set to 190-195 kg. A high level is output when the threshold is not reached, and a low level is output when the threshold is reached.

[0029] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A load detection circuit applied to an electric tricycle, characterized by, It includes a microcontroller minimum system, a vehicle controller, a first pressure sensor, and a second pressure sensor; The minimum system of a single-chip microcomputer includes a main control MCU, a power supply circuit, a reset circuit, and a crystal oscillator; The vehicle controller is connected to the P18 pin of the main control MCU via a one-wire bus; The first pressure sensor and the second pressure sensor are both located on the rear seat cushion; the detection end of the first pressure sensor inputs two signals to the P1.1 and P1.2 pins of the first pressure sensing chip respectively; the DO pin of the first pressure sensing chip is connected to the P19 pin of the main control MCU; the first pressure sensing chip outputs a high level of 3.3V or a low level of 0V. The detection end of the second pressure sensor inputs two signals to the P1.1 and P1.2 pins of the second pressure sensor chip respectively; the DO pin of the second pressure sensor chip is connected to the P27 pin of the main control MCU; the second pressure sensor chip outputs a high level of 3.3V or a low level of 0V.

2. The load detection circuit applied to the electric tricycle according to claim 1, characterized in that, The first pressure sensor is a thin-film resistive sensor.

3. The load detection circuit for electric tricycles according to claim 1 or 2, characterized in that, The starting pressure of the first pressure sensor is set to 25-30 kg.

4. The load detection circuit applied to the electric tricycle according to claim 1, characterized in that, The second pressure sensor is a piezoelectric weighing sensor.

5. The load detection circuit for use in an electrically powered tricycle according to claim 1 or 4, wherein The starting pressure of the second pressure sensor is set to 190-195 kg.

6. The load detection circuit applied to an electric tricycle according to claim 1, characterized by, The power supply circuit converts 12V to 3.3V to power the microcontroller minimum system and the first and second pressure sensors.

7. The load detection circuit applied to the electric tricycle according to claim 6, characterized by, The power supply circuit includes an AMS1117 power chip; a 12V power supply is connected in series with a 10A fuse and a diode, and then connected to the Vin terminal of the power chip; the output terminal of the power chip outputs a 3.3V voltage; the GND terminal of the power chip is grounded. Two 10uF capacitors are connected in parallel between the output terminal of the diode and the ground terminal; two 10nF capacitors are connected in parallel between the output terminal of the power supply chip and the ground terminal.

8. The load detection circuit applied to an electric tricycle according to claim 1, characterized by, The vehicle controller adjusts the output current to control the motor torque.

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