Towing vehicle and trailer connection state detection circuit and towed vehicle

Abstract

The application discloses a tractor and trailer connection state detection circuit and a towing vehicle, and belongs to the technical field of towing vehicles. The tractor and trailer connection state detection circuit is arranged on the tractor. The connection state detection circuit comprises at least one driving circuit, an output end of the driving circuit is used for electrical connection with a load in the trailer, and the driving circuit is configured to drive the load to work; at least one signal acquisition circuit, an input end of the signal acquisition circuit is electrically connected with the output end of the driving circuit, the signal acquisition circuit is configured to generate a first signal when the output end of the driving circuit is suspended or generate a second signal when the output end of the driving circuit is connected with the load; and a control circuit, a first input end of the control circuit is electrically connected with an output end of the signal acquisition circuit, the control circuit is configured to determine that the tractor is connected with the trailer when the second signal is received, and determine that the tractor is not connected with the trailer when the first signal is received. The cost is relatively low, and the compatibility is high.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of towing vehicles, and particularly relates to a tractor-trailer connection state detection circuit and a towing vehicle. BACKGROUND

[0002] With the rapid development of the automobile industry, people's functional requirements for automobiles are getting higher and higher, and the vehicle rear trailer has become the focus of users. Among the vehicle models on the market, the rear trailer usually has the functions of warning rear vehicles such as rear trailer rear turn signal, brake light, fog light, etc., and also has a series of logical judgments such as instrument prompt, driving mode switching, driving speed limitation, etc. for identifying the rear trailer by the towing vehicle. To realize the above functions, it is necessary to ensure that the rear trailer is connected with the towing vehicle. In the related art, an electromagnetic switch is arranged at the power supply position, and the electromagnetic induction is used to judge whether the rear trailer is connected with the towing vehicle, which has low compatibility and high cost. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a tractor-trailer connection state detection circuit and a towing vehicle, which has low cost, and generally the trailer has a load that can be connected with the output end of the driving circuit, so the detection circuit of the present application is suitable for various trailers and has high compatibility.

[0004] In a first aspect, the present application provides a tractor-trailer connection state detection circuit arranged in a tractor, which comprises:

[0005] at least one driving circuit, the output end of the driving circuit being used for electrical connection with a load in a trailer, and the driving circuit being configured to drive the load to work;

[0006] at least one signal acquisition circuit, the input end of the signal acquisition circuit being electrically connected with the output end of the driving circuit, and the signal acquisition circuit being configured to generate a first signal when the output end of the driving circuit is suspended, or generate a second signal when the output end of the driving circuit is connected with the load;

[0007] a control circuit, the first input end of the control circuit being electrically connected with the output end of the signal acquisition circuit, and the control circuit being configured to determine that the tractor is connected with the trailer when the second signal is received, and determine that the tractor is not connected with the trailer when the first signal is received.

[0008] According to an embodiment of the present application, the tractor-trailer connection state detection circuit further comprises a first unidirectional conduction device, the input end of the first unidirectional conduction device being electrically connected with the output end of the driving circuit, and the output end of the first unidirectional conduction device being used for electrical connection with the load in the trailer, and the signal acquisition circuit comprises:

[0009] a comparator, a negative input terminal of the comparator being configured to be connected to a reference voltage, and an output terminal of the comparator being electrically connected to a first input terminal of the control circuit;

[0010] a first resistor, a first terminal of the first resistor being electrically connected to the first power supply voltage node, and a second terminal of the first resistor being electrically connected to the positive input terminal of the comparator and the output terminal of the first unidirectional conducting device respectively;

[0011] The reference voltage is less than the first power supply voltage.

[0012] According to an embodiment of the present application, the impedance of the first resistor is greater than the impedance of the load in the trailer.

[0013] According to an embodiment of the present application, the signal acquisition circuit further comprises:

[0014] a second unidirectional conducting device, an input terminal of the second unidirectional conducting device being electrically connected to the second terminal of the first resistor and the positive input terminal of the comparator respectively, and an output terminal of the second unidirectional conducting device being electrically connected to the output terminal of the first unidirectional conducting device.

[0015] According to an embodiment of the present application, the signal acquisition circuit further comprises:

[0016] a second resistor, a first terminal of the second resistor being electrically connected to the first power supply voltage node;

[0017] a third resistor, a first terminal of the third resistor being electrically connected to a second terminal of the second resistor and the negative input terminal of the comparator respectively, and a second terminal of the third resistor being electrically connected to the ground node.

[0018] According to an embodiment of the present application, the signal acquisition circuit further comprises:

[0019] a fourth resistor, a first terminal of the fourth resistor being electrically connected to the second power supply voltage node, and a second terminal of the fourth resistor being electrically connected to the output terminal of the comparator and the first input terminal of the control circuit respectively;

[0020] a capacitor, a first terminal of the capacitor being electrically connected to the second terminal of the fourth resistor, and a second terminal of the capacitor being electrically connected to the ground node;

[0021] The second power supply voltage is less than the first power supply voltage.

[0022] According to an embodiment of the present application, an output terminal of the control circuit is electrically connected to an input terminal of the driving circuit, a second input terminal of the control circuit is configured to be connected to a load driving signal, and the control circuit is further configured to control the driving circuit to supply power to the load when the load driving signal is received.

[0023] According to one embodiment of the present application, the driving circuit has a feedback port, the feedback port is electrically connected with the third input end of the control circuit, and the driving circuit is further configured to transmit the current value of the output port to the control circuit through the feedback port.

[0024] According to one embodiment of the present application, the control circuit is further configured to control the driving circuit to stop working when the tractor is connected with the trailer, the control circuit receives the load driving signal, and the current value of the output port is less than the current threshold.

[0025] In a second aspect, the present application provides a towed vehicle, including a tractor and a trailer, the tractor is used to be connected with the trailer, the tractor includes a vehicle body controller, and the vehicle body controller includes the aforementioned tractor and trailer connection state detection circuit.

[0026] According to the tractor and trailer connection state detection circuit and the towed vehicle of the embodiments of the present application, when the output end of the driving circuit is suspended, it indicates that the output end of the driving circuit is not connected with the load in the trailer, so it can be determined that the tractor is not connected with the trailer, and when the output end of the driving circuit is connected with the load, it indicates that the output end of the driving circuit is connected with the load in the trailer, so it can be determined that the tractor is connected with the trailer, the cost is low, and generally the trailer has a load that can be connected with the output end of the driving circuit, so the detection circuit of the present application is suitable for various trailers and has high compatibility.

[0027] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings, wherein:

[0029] Figure 1 is a structural block diagram of the tractor and trailer connection state detection circuit provided by the embodiments of the present application;

[0030] Figure 2 is a circuit diagram of the tractor and trailer connection state detection circuit provided by the embodiments of the present application;

[0031] Figure 3 is an equivalent diagram when the output end of the driving circuit is connected with the load provided by the embodiments of the present application;

[0032] Figure 4 is a working flowchart of the control circuit provided by the embodiments of the present application.

[0033] REFERENCE NUMERALS:

[0034] The drive circuit 10, the signal acquisition circuit 20, the control circuit 30, the first to second unidirectional conducting devices D1-D2, the first to fourth resistors R1-R4, the capacitor C, and the comparator A. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below are exemplary and are for the purpose of explanation only, and are not to be understood as limiting the present application.

[0036] In the following description, "circuit" refers to a conductive loop formed by at least one element or sub-circuit through electrical or electromagnetic connection. When it is said that an element or circuit is "coupled to" or "connected to" another element or that the element / circuit is "coupled between" or "connected between" two nodes, it can be directly coupled or connected to another element or there can be an intermediate element, and the connection between the elements can be physical, logical, or a combination thereof. In contrast, when it is said that an element is "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element.

[0037] In the description, the terms "first", "second", and the like are used to distinguish similar objects, and are not used to describe a particular order or sequence. It should be understood that the numerical descriptors used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described here, and the objects distinguished by "first", "second", etc. are usually a class, and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the objects before and after are in a "or" relationship.

[0038] In addition, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0039] In order to meet the traffic, transportation and people's leisure and entertainment, more and more towing vehicles are used, such as towing trucks, semi-trailer trucks, box trailers, boat trailers and the like. The towing vehicle includes a tractor and a trailer, the tractor is connected with the trailer through a traction part, the trailer is used to accommodate goods, and the tractor drives the trailer to move through the traction part. In order to make the towing vehicle normally run, it is necessary to ensure that the tractor and the trailer are reliably connected.

[0040] In the related art, an electromagnetic induction switch is arranged at the trailer power connection port of the tractor, and a magnet is arranged at the power connection port of the trailer. When the plug is plugged, the electromagnetic induction switch is attracted and closed by the magnet, and the controller collects the change of the electromagnetic induction switch signal to feed back the trailer connection signal to the whole vehicle, so as to determine that the tractor and the trailer are connected. However, the electromagnetic induction switch is easy to be disturbed by the outside, and misjudgment is easy to occur. At the same time, the price of the electromagnetic switch is higher than that of other schemes, and some trailers do not have magnets, so the compatibility of the scheme using the electromagnetic induction switch is low, and the cost is high.

[0041] Reference Figure 1 , Figure 1 The structure block diagram of the tractor and trailer connection state detection circuit provided by the embodiment of the application is shown. One embodiment of the application provides a tractor and trailer connection state detection circuit arranged in the tractor. The connection state detection circuit includes at least one driving circuit 10, at least one signal acquisition circuit 20 and a control circuit 30. The output end of the driving circuit 10 is used to be electrically connected with the load in the trailer, and the driving circuit 10 is configured to drive the load to work. The input end of the signal acquisition circuit 20 is electrically connected with the output end of the driving circuit 10, and the signal acquisition circuit 20 is configured to generate a first signal when the output end of the driving circuit 10 is suspended, or generate a second signal when the output end of the driving circuit 10 is connected with the load. The first input end of the control circuit 30 is electrically connected with the output end of the signal acquisition circuit 20, and the control circuit 30 is configured to determine that the tractor and the trailer are connected when the second signal is received, and determine that the tractor and the trailer are not connected when the first signal is received.

[0042] The tractor is mainly used to provide enough power to tow the trailer, and the trailer is mainly used to carry goods. The trailer can be closed, open, container type, etc., and the specific structure of the trailer can be designed according to the transportation demand. For example, the trailer can be a rear-mounted trailer.

[0043] The tractor is usually provided with a body controller, which is an integrated electronic control unit responsible for managing and coordinating multiple body-related electrical systems and functions in the tractor. For example, the body controller can be used to control the functions of the vehicle lights, door locks, power windows, seat adjustment, etc.

[0044] The tractor-trailer connection state detection circuit can be integrated in the vehicle body controller. The output end of the drive circuit 10 is connected to the load in the trailer, mainly used to provide power for the load. The working state of the drive circuit 10 directly reflects the connection state of the tractor and the trailer. When the tractor and the trailer are in the connected state, the drive circuit 10 provides power for the trailer load through the output end, and the current or voltage output of the drive circuit 10 also represents a kind of symbol of the connection state.

[0045] It should be noted that the drive circuit 10 can have multiple output ports, each of which can be used to electrically connect with a load. The tractor-trailer connection state detection circuit can also include multiple drive circuits 10, each of which is connected with a load. One drive circuit 10 is connected with multiple loads, or the connection state detection circuit includes multiple drive circuits 10, and whether the tractor and the trailer are connected can be determined according to any one of the multiple loads. When one of the loads fails or one of the output ports of the drive circuit 10 fails, whether the tractor and the trailer are connected can be determined through the connection of the other output ports and the loads, thereby improving the accuracy of the connection state monitoring.

[0046] The number of drive circuits 10 and the number of output ports of the drive circuit 10 can be selected according to the actual application scenario, which is not limited here. For example, the connection state detection circuit can include three drive circuits 10, each having an output port, and the output ports are respectively used to connect with the brake light, the left turn signal light and the right turn signal light.

[0047] The load in the trailer can be any load that consumes power in the trailer. For example, the load in the trailer can be a brake light, a turn signal light, a wiper, etc.

[0048] The number of signal acquisition circuits 20 is the same as the number of output ports of the drive circuit 10. The input end of the signal acquisition circuit 20 is electrically connected with the output end of the drive circuit 10. The signal acquisition circuit 20 monitors the voltage and current state of the output end of the drive circuit 10 in real time, and generates different signals according to different working states of the drive circuit 10: when the output end of the drive circuit 10 is in a suspended state, i.e. not connected with a load, the signal acquisition circuit 20 generates a first signal; when the output end of the drive circuit 10 is connected with the trailer load circuit, the signal acquisition circuit 20 generates a second signal, and the drive circuit 10 normally provides power to the load.

[0049] It should be noted that the first signal and the second signal can be a level signal or a voltage value. For example, the first signal is a high-level signal, and the second signal is a low-level signal; or the voltage value of the first signal is greater than the voltage threshold, and the voltage value of the second signal is less than the voltage threshold, etc.

[0050] The first input end of the control circuit 30 is electrically connected with the output end of the signal acquisition circuit 20, when the second signal is received, the control circuit 30 determines that the tractor and the trailer are in the connected state; when the first signal is received, the control circuit 30 determines that the tractor and the trailer are not connected.

[0051] In some embodiments, the output end of the control circuit 30 can also be connected with the instrument panel control module in the vehicle body controller, the connection state of the tractor and the trailer is fed back to the driver through the instrument panel, so that the driver can find the connection abnormality in time, and the safety and stability of the system are improved.

[0052] The connection state of the tractor and the trailer can be detected in real time through the circuit, and fed back to the control circuit 30 through the signal, which helps the system to find the connection abnormality in time, and can effectively avoid system failure or accidents caused by abnormal connection state. In addition, generally, the trailer has a load that can be connected with the output end of the drive circuit 10, so that the design of the circuit has high adaptability and expandability, and can be applied to various combinations of tractors and trailers, meeting the diversified needs in actual application.

[0053] According to the connection state detection circuit of the tractor and the trailer, when the output end of the drive circuit 10 is suspended, it indicates that the output end of the drive circuit 10 is not connected with the load in the trailer, so it can be determined that the tractor and the trailer are not connected, and when the output end of the drive circuit 10 is connected with the load, it indicates that the output end of the drive circuit 10 is connected with the load in the trailer, so it can be determined that the tractor and the trailer are connected, which has low cost, and generally, the trailer has a load that can be connected with the output end of the drive circuit 10, so that the detection circuit of the present application is applicable to various trailers, and has high compatibility.

[0054] Reference Figure 2 , Figure 2 The connection state detection circuit of the tractor and the trailer provided by the embodiment of the present application is shown. In some embodiments, the connection state detection circuit of the tractor and the trailer further comprises a first unidirectional conduction device D1, the input end of the first unidirectional conduction device D1 is electrically connected with the output end of the drive circuit 10, the output end of the first unidirectional conduction device D1 is used for being electrically connected with the load in the trailer, the signal acquisition circuit 20 comprises a comparator A and a first resistor R1. The negative phase input end of the comparator A is used for being connected with a reference voltage, the output end of the comparator A is electrically connected with the first input end of the control circuit 30; the first end of the first resistor R1 is electrically connected with the first power supply voltage node, the second end of the first resistor R1 is respectively electrically connected with the positive phase input end of the comparator A and the output end of the first unidirectional conduction device D1; the reference voltage is less than the first power supply voltage.

[0055] The first resistor R1 is electrically connected between the first power supply voltage node and the output terminal of the first unidirectional conducting device D1. When the output terminal of the driving circuit 10 is left open, the loop formed by the first power supply voltage node and the first resistor R1 is open, and the voltage at the positive input terminal of the comparator A is the first power supply voltage. The reference voltage input to the negative input terminal of the comparator A is less than the first power supply voltage, i.e., the voltage at the positive input terminal of the comparator A is greater than the voltage at the negative input terminal of the comparator A. Therefore, the output terminal of the comparator A outputs a high-level signal, i.e., the first signal is a high-level signal.

[0056] With reference to Figure 3 , Figure 3 An equivalent diagram when the output terminal of the driving circuit 10 is connected to a load is shown. When the output terminal of the driving circuit 10 is connected to a load (for example, a brake lamp LED), the first power supply voltage node forms a complete loop with the first resistor R1 and the load. It should be noted that the load in the trailer usually has a small internal resistance. In this case, the voltage at the positive input terminal of the comparator A is the voltage across the load, and the load has a small internal resistance. Therefore, the voltage across the load is small, and the voltage at the positive input terminal of the comparator A is less than the voltage at the negative input terminal of the comparator A. Therefore, the output terminal of the comparator A outputs a low-level signal, i.e., the second signal is a low-level signal.

[0057] Therefore, the control circuit 30 can determine whether the towing vehicle and the trailer are connected by the level of the signal output from the output terminal of the comparator A.

[0058] The specific type of the first unidirectional conducting device D1 can be selected according to the actual application scenario, which is not limited here. For example, the first unidirectional conducting device D1 can be a diode.

[0059] In some embodiments, the impedance of the first resistor R1 is greater than the impedance of the load in the trailer.

[0060] When the load in the trailer is a resistive load, the resistance value of the first resistor R1 is greater than the resistance value of the load in the trailer, so that the current between the first power supply voltage node and the output terminal of the driving circuit 10 is small. When determining whether the towing vehicle and the trailer are connected, the current flowing from the output terminal of the driving circuit 10 to the load in the trailer is also small, thereby avoiding false triggering of the load.

[0061] As an example, the load is a brake light. When determining whether the towing vehicle and the trailer are connected, if the resistance of the first resistor R1 is small, the current flowing through the output end of the driving circuit 10 is large. That is, as long as the towing vehicle and the trailer are connected and the connection state is determined, the brake light will be on, which will mislead the driver of the following vehicle that the trailer vehicle is braking. The resistance of the first resistor R1 is greater than the resistance of the load in the trailer, so that the current flowing through the output end of the driving circuit 10 is small, and the brake light will not be on when the towing vehicle and the trailer are connected and the connection state is determined. The brake light will only be on when the driving circuit 10 is powered.

[0062] It should be noted that the resistance of the first resistor R1 can be selected according to the actual application scenario, which is not limited here. Generally, the resistance of the first resistor R1 is much greater than the resistance of the load in the trailer, so as to reduce the possibility of false triggering of the load as much as possible. For example, the resistance of the first resistor R1 can be 3MΩ.

[0063] In some embodiments, the signal acquisition circuit 20 further includes a second unidirectional conduction device D2. The input end of the second unidirectional conduction device D2 is electrically connected to the second end of the first resistor R1 and the positive input end of the comparator A, respectively. The output end of the second unidirectional conduction device D2 is electrically connected to the output end of the first unidirectional conduction device D1.

[0064] The second unidirectional conduction device D2 is electrically connected between the positive input end of the comparator A and the output end of the first unidirectional conduction device D1, which can isolate the output current when the driving circuit 10 supplies power to the load, so as to avoid the current at the output end of the driving circuit 10 from flowing back to the positive input end of the comparator A, thereby affecting the voltage at the positive input end of the comparator A and causing inaccurate determination results.

[0065] The specific type of the second unidirectional conduction device D2 can be selected according to the actual application scenario, which is not limited here. For example, the second unidirectional conduction device D2 can be a diode.

[0066] In some embodiments, the signal acquisition circuit 20 further includes a second resistor R2 and a third resistor R3. The first end of the second resistor R2 is electrically connected to the first power supply voltage node. The first end of the third resistor R3 is electrically connected to the second end of the second resistor R2 and the negative input end of the comparator A, respectively. The second end of the third resistor R3 is electrically connected to the ground node.

[0067] The second resistor R2 and the third resistor R3 are connected in series between the first power supply voltage node and the ground node, and are mainly used to provide a reference voltage for the negative input end of the comparator A. The reference voltage is the voltage across the third resistor R3.

[0068] The resistance values of the second resistor R2 and the third resistor R3 can affect the size of the reference voltage, and the specific values of the resistance values of the second resistor R2 and the third resistor R3 can be selected according to actual application scenarios, which are not limited here.

[0069] As an example, the first supply voltage is 12V, the resistance value R2 of the second resistor R2 is 33KΩ, and the resistance value R3 of the third resistor R3 is 68KΩ. Then the reference voltage is .

[0070] In some embodiments, the signal acquisition circuit 20 further comprises a fourth resistor R4 and a capacitor C. The first end of the fourth resistor R4 is electrically connected to the second supply voltage node, and the second end of the fourth resistor R4 is electrically connected to the output end of the comparator A and the first input end of the control circuit 30, respectively. The first end of the capacitor C is electrically connected to the second end of the fourth resistor R4, and the second end of the capacitor C is electrically connected to the ground node. The second supply voltage is less than the first supply voltage.

[0071] The fourth resistor R4 is electrically connected between the second supply voltage node and the output end of the comparator A. When the voltage at the positive input end of the comparator A is greater than the voltage at the negative input end, the output end of the comparator A is in a high resistance state, and the second supply voltage is transmitted to the first input end of the control circuit 30 through the fourth resistor R4. At this time, the voltage received by the first input end of the control circuit 30 is the second supply voltage.

[0072] When the voltage at the negative input end of the comparator A is greater than the voltage at the positive input end, the output end of the comparator A is electrically connected to the ground node through the internal of the comparator A, which is equivalent to the first input end of the control circuit 30 being electrically connected to the ground node. The voltage received by the first input end is zero voltage.

[0073] Therefore, by detecting the voltage at the output end of the comparator A, the size relationship between the positive input end and the negative input end of the comparator A can be determined, and in combination with the foregoing embodiments, it can be determined whether the towing vehicle and the trailer are connected.

[0074] The capacitor C is mainly used for filtering and preventing voltage mutation, absorbing peak interference, and avoiding the influence of the peak on the judgment result.

[0075] The specific value of the second supply voltage is selected according to the actual application scenario, which is not limited here. For example, when the control circuit 30 uses a 3.3V micro control chip, the second supply voltage can be 3.3V.

[0076] In some embodiments, the output end of the control circuit 30 is electrically connected to the input end of the driving circuit 10, the second input end of the control circuit 30 is used to input the load driving signal, and the control circuit 30 is further configured to control the driving circuit 10 to supply power to the load when the load driving signal is received.

[0077] The load driving signal refers to a signal for driving the load to act. For example, if the output end of the driving circuit 10 is used to be connected with the brake lamp, the load driving signal refers to the brake signal.

[0078] The power supply end of the driving circuit 10 can be electrically connected with the first power supply voltage node. When the second input end of the control circuit 30 receives the load driving signal, the control circuit 30 controls the driving circuit 10 to transmit the first power supply voltage to the load to supply power to the load.

[0079] As an example, the output end of the driving circuit 10 is used to be connected with the brake lamp, the control circuit 30 includes a first output port and a second output port, the first output port is connected with the input port of the driving circuit 10, and the second output port is electrically connected with the enable port of the driving circuit 10. When the second input end of the control circuit 30 receives the load driving signal, the first output port and the second output port both output high-level signals, and the driving circuit 10 transmits the first power supply voltage to the brake lamp, so as to light up the brake lamp.

[0080] Referring to Figure 4 , Figure 4 The working flow of the control circuit 30 provided by the embodiment of the application is shown. The load driving signal can also be a vehicle wake-up signal. After the control circuit 30 receives the vehicle wake-up signal, the signal acquisition circuit 20 outputs the signal at the output end, and it is determined whether the tractor and the trailer are connected. When the tractor and the trailer are connected, the control circuit 30 controls the driving circuit 10 to provide power to the load according to the load driving signal received by the second input end.

[0081] In some embodiments, the driving circuit 10 has a feedback port, the feedback port is electrically connected with the third input end of the control circuit 30, and the driving circuit 10 is further configured to transmit the current value of the output port to the control circuit 30 through the feedback port.

[0082] The driving circuit 10 feeds back the current value of the output port to the third input end of the control circuit 30 through the feedback port, so that the control circuit 30 can monitor the power supply condition of the driving circuit 10 to the load in real time, and adjust the working state of the driving circuit 10 according to the power supply condition, so as to realize accurate control and optimization of the driving circuit 10.

[0083] For example, when the current of the output port of the driving circuit 10 exceeds the set threshold value, the feedback port feeds back the corresponding current information to the control circuit 30, and the control circuit 30 can reduce the current and prevent current overload or overheating phenomenon by adjusting the working parameters of the driving circuit 10, such as adjusting the driving voltage or changing the driving frequency. On the contrary, if the output current is too low, the control circuit 30 can appropriately increase the driving current to ensure the stable operation and performance of the system.

[0084] In some embodiments, the control circuit 30 is further configured to control the drive circuit 10 to stop working when the trailer is connected to the towing vehicle, the control circuit 30 receives the load driving signal and the current value of the output port is less than the current threshold.

[0085] When the trailer is connected to the towing vehicle, that is, the output of the drive circuit 10 is connected to the load, the drive circuit 10 can supply power to the load. The control circuit 30 receives the load driving signal, indicating that the control circuit 30 will control the drive circuit 10 to supply power to the load, and the current value of the output port is less than the current threshold, indicating that the drive circuit 10 does not supply power to the load, indicating that the drive circuit 10 may enter a thermal protection state, at which time the control circuit 30 controls the drive circuit 10 to stop working, so that the drive circuit 10 dissipates heat, avoiding damage to internal electrical components of the drive circuit 10 caused by excessive temperature.

[0086] As an example, the control circuit 30 further includes a third output port, and the drive circuit 10 has a fault reset port, the fault reset port is electrically connected to the third output port, when the trailer is connected to the towing vehicle, the control circuit 30 receives the load driving signal and the current value of the output port is less than the current threshold, the control circuit 30 can apply a low-level signal to the fault reset port, so that the drive circuit 10 dissipates heat for a period of time before outputting.

[0087] The specific value of the current threshold can be selected according to the actual application scenario, which is not limited here. For example, the current threshold can be 0.1A or 0.2A, etc.

[0088] One embodiment of the present application provides a towed vehicle, including a towing vehicle and a trailer, the towing vehicle is used to connect with the trailer, the towing vehicle includes a vehicle body controller, the vehicle body controller includes the aforementioned towing vehicle and trailer connection state detection circuit.

[0089] The specific structure and working principle of the towing vehicle and trailer connection state detection circuit can refer to the aforementioned embodiments, which will not be described here.

[0090] According to the towed vehicle of the present application, when the output of the drive circuit 10 is suspended, it indicates that the output of the drive circuit 10 is not connected to the load in the trailer, so it can be determined that the towing vehicle is not connected to the trailer, and when the output of the drive circuit 10 is connected to the load, it indicates that the output of the drive circuit 10 is connected to the load in the trailer, and it can be determined that the towing vehicle is connected to the trailer, which is low in cost, and generally the trailer has a load that can be connected to the output of the drive circuit 10, so the detection circuit of the present application is suitable for various trailers, and has high compatibility.

[0091] While the embodiments of the application have been shown and described, it is to be understood that the embodiments can be varied, modified, substituted and changed by those skilled in the art without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A circuit for detecting the connection status between a tractor and a trailer, characterized in that, The connection status detection circuit, installed in the tractor, includes: At least one drive circuit, the output of which is electrically connected to a load in the trailer, the drive circuit being configured to drive the load to operate; A first unidirectional conducting device, wherein the input terminal of the first unidirectional conducting device is electrically connected to the output terminal of the drive circuit, and the output terminal of the first unidirectional conducting device is used to be electrically connected to the load in the trailer; At least one signal acquisition circuit, wherein the input terminal of the signal acquisition circuit is electrically connected to the output terminal of the drive circuit, and the signal acquisition circuit is configured to generate a first signal when the output terminal of the drive circuit is floating, or to generate a second signal when a load is connected to the output terminal of the drive circuit; A control circuit, wherein the first input terminal of the control circuit is electrically connected to the output terminal of the signal acquisition circuit, and the control circuit is configured to determine that the tractor and the trailer are connected when the second signal is received, and to determine that the tractor and the trailer are not connected when the first signal is received. The signal acquisition circuit includes: The comparator has a negative input terminal for connecting to a reference voltage, and its output terminal is electrically connected to the first input terminal of the control circuit. A first resistor, the first end of which is electrically connected to a first power supply voltage node, and the second end of which is electrically connected to the non-inverting input terminal of the comparator and the output terminal of the first unidirectional conducting device, respectively. The reference voltage is less than the first supply voltage; The output terminal of the control circuit is electrically connected to the input terminal of the drive circuit. The second input terminal of the control circuit is used to receive the load drive signal. The control circuit is also configured to control the drive circuit to supply power to the load when it receives the load drive signal.

2. The tractor-trailer connection status detection circuit according to claim 1, characterized in that, The impedance of the first resistor is greater than the impedance of the load.

3. The tractor-trailer connection status detection circuit according to claim 1, characterized in that, The signal acquisition circuit also includes: The second unidirectional conducting device has its input terminal electrically connected to the second terminal of the first resistor and the non-inverting input terminal of the comparator, respectively, and its output terminal is electrically connected to the output terminal of the first unidirectional conducting device.

4. The tractor-trailer connection status detection circuit according to claim 1, characterized in that, The signal acquisition circuit also includes: The second resistor has its first end electrically connected to the first power supply voltage node. The third resistor has its first end electrically connected to the second end of the second resistor and the negative phase input of the comparator, and its second end electrically connected to the ground node.

5. The tractor-trailer connection status detection circuit according to claim 1, characterized in that, The signal acquisition circuit also includes: The fourth resistor has its first end electrically connected to the second power supply voltage node, and its second end electrically connected to both the output terminal of the comparator and the first input terminal of the control circuit. A capacitor, wherein the first terminal of the capacitor is electrically connected to the second terminal of the fourth resistor, and the second terminal of the capacitor is electrically connected to a grounding node; The second supply voltage is less than the first supply voltage.

6. The tractor-trailer connection status detection circuit according to any one of claims 1-4, characterized in that, The drive circuit has a feedback port, which is electrically connected to the third input terminal of the control circuit. The drive circuit is also configured to transmit the current value of the output port to the control circuit through the feedback port.

7. The tractor-trailer connection status detection circuit according to any one of claims 1-4, characterized in that, The control circuit is further configured to control the drive circuit to stop working when the tractor is connected to the trailer, the control circuit receives the load drive signal and the current value of the output port is less than the current threshold.

8. A trailer vehicle, characterized in that, It includes a tractor and a trailer, the tractor being used to connect to the trailer, the tractor including a body controller, the body controller including a tractor-trailer connection status detection circuit according to any one of claims 1-7.

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