CN117162990A - Trailer braking control method, device, equipment and storage medium - Google Patents

Abstract

The invention provides a control method, a device, equipment and a storage medium for trailer braking, wherein the method comprises the following steps: acquiring actual braking air pressure and required braking air pressure of a trailer at a target moment, wherein the required formulated air pressure is determined according to at least one of a braking signal sent by a tractor, an anti-lock signal sent by the trailer or an anti-rollover signal sent by the trailer; determining the energizing time and duty cycle of an electromagnetic valve on the trailer based on the actual brake air pressure and the demanded brake air pressure; and adjusting the braking air pressure of the trailer according to the energizing time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer. The control method for braking the trailer can improve the braking performance of the trailer.

Description

Trailer braking control method, device, equipment and storage medium

Technical Field

The invention relates to the technical field of intelligent driving, in particular to a trailer braking control method, device and equipment and a storage medium.

Background

Commercial vehicles, in particular semi-trailer traction vehicles, play a very important role in modern logistics. The semi-trailer traction vehicle comprises a tractor and a trailer, wherein the trailer has no traction driving capability and is towed by the tractor. The front half of the trailer is mounted on the traction saddle of the rear section of the tractor, and the bridge behind the tractor bears a part of the weight of the trailer.

Currently, semi-trailer traction vehicles generally employ mechanical pneumatic braking, which is typically single-loop pneumatic control, to provide a braking signal for the trailer pipeline. During braking, when the driver depresses the brake pedal, a brake signal is transmitted in pneumatic form from the tractor to the trailer.

However, since the pneumatic brake signal is transmitted from the tractor to the trailer, the tractor brakes prior to the trailer, resulting in an uncoordinated braking between the tractor and the trailer. And the phenomenon of back dragging or jerking of the vehicle can be caused by the disharmony of the braking between the tractor and the trailer, so that the driving safety is influenced.

Disclosure of Invention

The embodiment of the invention provides a control method, a device, equipment and a storage medium for braking of a trailer, which are used for solving the problem that the braking of a tractor and the trailer is not coordinated at present.

In a first aspect, an embodiment of the present invention provides a trailer provided with a trailer electronic control device for controlling braking of the trailer, where the control method includes:

acquiring actual braking air pressure and required braking air pressure of a trailer at a target moment, wherein the required formulated air pressure is determined according to at least one of a braking signal sent by a tractor, an anti-lock signal sent by the trailer or an anti-rollover signal sent by the trailer;

Determining the energizing time and duty cycle of an electromagnetic valve on the trailer based on the actual brake air pressure and the demanded brake air pressure;

and adjusting the braking air pressure of the trailer according to the energizing time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer.

In one possible implementation, obtaining a desired braking air pressure of the trailer at a target time includes:

when only a braking signal sent by the tractor is received, determining first braking air pressure of the trailer at a target moment based on the braking signal sent by the tractor, and taking the first braking air pressure as required braking air pressure;

when a braking signal sent by a tractor and an anti-lock signal sent by a trailer are received at the same time, taking second braking air pressure corresponding to the anti-lock signal at a target moment as required braking air pressure; when the anti-lock signal disappears, determining third braking air pressure of the trailer at the moment based on the received braking signal sent by the tractor, and taking the third braking air pressure as required braking air pressure;

when the rollover prevention signal and the anti-lock signal sent by the trailer are received at the same time, fourth braking air pressure corresponding to the anti-lock signal at the target moment is used as required braking air pressure; when the anti-lock signal disappears, determining fifth braking air pressure of the trailer at the moment based on the received anti-rollover signal, and taking the fifth braking air pressure as required braking air pressure;

When a braking signal sent by a tractor and an anti-rollover signal sent by a trailer are received at the same time, taking a sixth braking air pressure corresponding to the anti-rollover signal at a target moment as a required braking air pressure; when the rollover prevention signal disappears, the seventh braking air pressure of the trailer at the moment is determined based on the received braking signal sent by the tractor, and the seventh braking air pressure is used as the required braking air pressure.

In one possible implementation, determining a first brake air pressure of the trailer at a target time based on a brake signal sent by the tractor includes:

the first brake air pressure of the trailer at the target moment is determined based on the brake demand air pressure in the brake signal sent by the tractor at the target moment, the load distribution of the tractor and the trailer, and the speeds of the tractor and the trailer at the target moment respectively.

In one possible implementation, the anti-lock signal determination process is:

determining the slip rate of the trailer based on the speed of the trailer at the target moment and the wheel speed of the trailer; when the slip rate is greater than the slip rate threshold, an anti-lock signal is sent out;

the determination process of the rollover prevention signal comprises the following steps:

and when the lateral acceleration of the trailer at the target moment is detected to be larger than a preset acceleration threshold value, sending out a rollover prevention signal.

In one possible implementation, determining the energization time and duty cycle of the solenoid valve on the trailer based on the actual brake air pressure and the demanded brake air pressure includes:

when the required braking air pressure is larger than the actual braking air pressure, when the pressure difference is larger than a first preset pressure difference threshold value, the air inlet electromagnetic valve is set to be electrified continuously, and the duty ratio of the air inlet electromagnetic valve is set to be a first duty ratio; when the pressure difference is monitored to be smaller than a first preset pressure difference threshold value, setting the duty ratio of the air inlet electromagnetic valve as a second duty ratio, and stopping electrifying when the pressure difference is monitored to be equal to the second preset pressure difference threshold value; the differential pressure is the difference between the required braking air pressure and the actual braking air pressure, the first preset differential pressure threshold value is larger than the second preset differential pressure threshold value, and the first duty ratio is larger than the second duty ratio;

when the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is larger than a third preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is the first duty ratio, and the electrification is stopped when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value;

when the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is smaller than a fifth preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is set to be a second duty ratio, and the electrification is stopped when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value; the third preset differential pressure threshold value is larger than the fifth preset differential pressure threshold value, and the fifth preset differential pressure threshold value is larger than the fourth preset differential pressure threshold value.

In one possible implementation, the trailer receives a brake signal sent by the tractor through a CAN signal line;

bridge control modules are arranged on the left side and the right side of the trailer, and an air inlet electromagnetic valve, an air outlet electromagnetic valve and a pressure sensor are arranged in the bridge control modules and are used for monitoring the actual pressure in the brake air chamber in real time;

the second brake air pressure includes a second left brake air pressure and a second right brake air pressure, and the second left brake air pressure and the second right brake air pressure are different; the fourth brake air pressure includes a fourth left brake air pressure and a fourth right brake air pressure, and the fourth left brake air pressure and the fourth right brake air pressure are different; the fifth brake air pressure includes a fifth left brake air pressure and a fifth right brake air pressure, and the fifth left brake air pressure and the fifth right brake air pressure are different; the sixth brake air pressure includes a sixth left brake air pressure and a sixth right brake air pressure, and the sixth left brake air pressure and the sixth right brake air pressure are different.

In a second aspect, an embodiment of the present invention provides a control device for braking a trailer, including:

the air pressure acquisition module is used for acquiring the actual braking air pressure and the required braking air pressure of the trailer at the target moment, and the required formulated air pressure is determined according to at least one of a braking signal sent by the tractor, an anti-lock signal sent by the trailer or an anti-rollover signal sent by the trailer;

The determining duty ratio module is used for determining the energizing time and duty ratio of the electromagnetic valve on the trailer based on the actual braking air pressure and the required braking air pressure;

and the adjusting module is used for adjusting the braking air pressure of the trailer based on the energizing time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer.

In one possible implementation manner, the air pressure acquisition module is used for determining the first braking air pressure of the trailer at the target moment based on the braking signal sent by the tractor when only the braking signal sent by the tractor is received, and taking the first braking air pressure as the required braking air pressure;

when a braking signal sent by a tractor and an anti-lock signal sent by a trailer are received at the same time, taking second braking air pressure corresponding to the anti-lock signal at a target moment as required braking air pressure; when the anti-lock signal disappears, determining third braking air pressure of the trailer at the moment based on the received braking signal sent by the tractor, and taking the third braking air pressure as required braking air pressure;

when the rollover prevention signal and the anti-lock signal sent by the trailer are received at the same time, fourth braking air pressure corresponding to the anti-lock signal at the target moment is used as required braking air pressure; when the anti-lock signal disappears, determining fifth braking air pressure of the trailer at the moment based on the received anti-rollover signal, and taking the fifth braking air pressure as required braking air pressure;

When a braking signal sent by a tractor and an anti-rollover signal sent by a trailer are received at the same time, taking a sixth braking air pressure corresponding to the anti-rollover signal at a target moment as a required braking air pressure; when the rollover prevention signal disappears, the seventh braking air pressure of the trailer at the moment is determined based on the received braking signal sent by the tractor, and the seventh braking air pressure is used as the required braking air pressure.

In one possible implementation, the air pressure obtaining module is configured to determine a first braking air pressure of the trailer at the target moment based on a braking demand air pressure in a braking signal sent by the tractor at the target moment, a load distribution of the tractor and the trailer, and speeds of the tractor and the trailer at the target moment, respectively.

In one possible implementation, the air pressure module is used for determining the slip rate of the trailer based on the speed of the trailer and the wheel speed of the trailer at the target moment; when the slip rate is greater than the slip rate threshold, an anti-lock signal is sent out;

the air pressure acquisition module is used for sending out a rollover prevention signal when detecting that the lateral acceleration of the trailer at the target moment is larger than a preset acceleration threshold value.

In one possible implementation manner, the determining duty ratio module is configured to, when the required braking air pressure is greater than the actual braking air pressure, set the air intake solenoid valve to be continuously energized and set the duty ratio of the air intake solenoid valve to be a first duty ratio when the differential pressure is greater than a first preset differential pressure threshold; when the pressure difference is monitored to be smaller than a first preset pressure difference threshold value, setting the duty ratio of the air inlet electromagnetic valve as a second duty ratio, and stopping electrifying when the pressure difference is monitored to be equal to the second preset pressure difference threshold value; the differential pressure is the difference between the required braking air pressure and the actual braking air pressure, the first preset differential pressure threshold value is larger than the second preset differential pressure threshold value, and the first duty ratio is larger than the second duty ratio;

When the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is larger than a third preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is the first duty ratio, and the electrification is stopped when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value;

when the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is smaller than a fifth preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is set to be a second duty ratio, and the electrification is stopped when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value; the third preset differential pressure threshold value is larger than the fifth preset differential pressure threshold value, and the fifth preset differential pressure threshold value is larger than the fourth preset differential pressure threshold value.

In one possible implementation, the trailer receives a brake signal sent by the tractor through a CAN signal line;

bridge control modules are arranged on the left side and the right side of the trailer, and an air inlet electromagnetic valve, an air outlet electromagnetic valve and a pressure sensor are arranged in the bridge control modules and are used for monitoring the actual pressure in the brake air chamber in real time;

the second brake air pressure includes a second left brake air pressure and a second right brake air pressure, and the second left brake air pressure and the second right brake air pressure are different; the fourth brake air pressure includes a fourth left brake air pressure and a fourth right brake air pressure, and the fourth left brake air pressure and the fourth right brake air pressure are different; the fifth brake air pressure includes a fifth left brake air pressure and a fifth right brake air pressure, and the fifth left brake air pressure and the fifth right brake air pressure are different; the sixth brake air pressure includes a sixth left brake air pressure and a sixth right brake air pressure, and the sixth left brake air pressure and the sixth right brake air pressure are different.

In a third aspect, an embodiment of the present invention provides a trailer electronic control device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the method as described above in the first aspect or any one of the possible implementations of the first aspect when the computer program is executed.

In a fourth aspect, an embodiment of the present invention provides a semi-trailer tractor comprising a tractor and a trailer, the trailer having mounted thereon the trailer electrical control apparatus of the third aspect above.

In a fifth aspect, embodiments of the present invention provide a computer readable storage medium storing a computer program which, when executed by a processor, implements the steps of the method as described above in the first aspect or any one of the possible implementations of the first aspect.

The embodiment of the invention provides a control method, a device, equipment and a storage medium for braking of a trailer, wherein the control method comprises the steps of firstly, acquiring actual braking air pressure and required braking air pressure of the trailer at a target moment, then determining the power-on time and duty ratio of an electromagnetic valve on the trailer based on the actual braking air pressure and the required braking air pressure, and finally, adjusting the braking air pressure of the trailer according to the power-on time and the duty ratio of the electromagnetic valve to change the braking strength of the trailer. According to the invention, the trailer electric control equipment is arranged on the trailer, so that the trailer is braked by means of a braking signal sent by the tractor, and a final required braking air pressure is determined according to an anti-rollover signal or an anti-lock signal sent by the trailer, so that the power-on time and the duty ratio of an electromagnetic valve on the trailer are determined according to the required braking air pressure and the actual detected braking air pressure. The braking of the trailer in the running process is not only simply dependent on the braking sent by the tractor, but also the proper required braking air pressure is determined based on the actual running condition of the wheel hanging end, so that the braking performance of the trailer is improved, and the driving safety is further improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a flowchart of an implementation of a control method for braking a trailer according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a control air path of a single-sided bridge control module according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a control device for braking a trailer according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a trailer electronic control device provided in an embodiment of the present invention;

fig. 5 is a schematic structural view of a traction semitrailer according to an embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the following description will be made by way of specific embodiments with reference to the accompanying drawings.

As described in the background art, a trailer is towed by a tractor without driving force, and when braking, a braking signal can only be transmitted from the tractor to the trailer in the form of air pressure, resulting in a braking imbalance between the tractor and the trailer.

In order to solve the problems in the prior art, the embodiment of the invention provides a trailer braking control method, a device, equipment and a storage medium. The following first describes a control method for braking a trailer provided by an embodiment of the present invention.

The trailer is provided with a trailer electric control module for controlling the braking of the trailer. Referring to fig. 1, a flowchart of an implementation of a trailer braking control method provided by an embodiment of the present invention is shown, and details are as follows:

and step S110, acquiring the actual braking air pressure and the required braking air pressure of the trailer at the target moment.

The demand-formulated air pressure is determined based on at least one of a brake signal sent by the tractor, an anti-lock signal sent by the trailer, or an anti-rollover signal sent by the trailer.

The bridge control modules are arranged on the left side and the right side of the trailer, each bridge control module comprises an air inlet electromagnetic valve, an air outlet electromagnetic valve and a pressure sensor, and the pressure on the left side and the right side can be independently controlled as the bridge control modules on the left side and the right side.

The actual braking air pressure of the trailer at the target moment can be collected through a pressure sensor in the bridge control module, and the actual braking air pressure collected by the pressure sensor is the actual air pressure in the braking chamber.

The trailer can be braked, anti-locked, anti-rollover and the like according to different road conditions and driving processes in the driving process, and different conditions can correspond to different control methods. The trailer electronic control module on the trailer can determine different braking control strategies according to the received signals.

In some embodiments, when only the brake signal sent by the tractor is received, the trailer determines a first brake air pressure of the trailer at the target time based on the brake signal sent by the tractor, and uses the first brake air pressure as the required brake air pressure.

In this embodiment, the tractor is assigned a brake demand air pressure during braking, and the trailer activates the brake function after receiving the brake demand signal from the tractor via the CAN signal. In order to ensure the running of the tractor and the trailer, the first brake air pressure of the trailer at the target moment is determined based on the brake demand air pressure in the brake signal sent by the tractor at the target moment, the load distribution of the tractor and the trailer and the speeds of the tractor and the trailer at the target moment respectively.

The first brake air pressure includes a first left brake air pressure and a first right brake air pressure, and the first left brake air pressure and the first right brake air pressure are the same.

In some embodiments, the wheels of the trailer may empty instantaneously when the trailer is in the speed bump or pit. Or when the trailer runs on a normal road, the emergency braking can cause wheels to have a locking and slipping tendency, and at the moment, if the trailer brakes only through a braking signal of the tractor, a great potential safety hazard can occur. At this time, the braking air pressure required by the trailer is determined according to the antilock brake, and the antilock brake determination process is as follows:

first, the slip ratio of the trailer is determined based on the vehicle speed of the trailer and the wheel speed of the trailer at the target time. The speed of the trailer and the wheel speed of the trailer may be obtained by sensors mounted on the trailer.

Then, whether the trailer is anti-lock is determined according to the slip rate of the trailer and the slip rate threshold value. And if the slip rate is greater than the slip rate threshold, an anti-lock signal is sent.

At this time, the braking signal sent by the tractor and the anti-lock signal sent by the trailer are received at the same time, and the braking air pressure corresponding to the braking signal and the braking air pressure corresponding to the anti-lock are different, so that a final braking air pressure needs to be arbitrated, and the running safety is ensured. The procedure for determination is as follows:

And when the braking signal sent by the tractor and the anti-lock signal sent by the trailer are received simultaneously, taking the second braking air pressure corresponding to the anti-lock signal at the target moment as the required braking air pressure. In the case of antilock braking, the air pressure of the left and right vehicles is different. The second brake air pressure includes a second left brake air pressure and a second right brake air pressure, and the second left brake air pressure and the second right brake air pressure are different.

When the anti-lock signal disappears, the third braking air pressure of the trailer at the moment is determined based on the received braking signal sent by the tractor, and the third braking air pressure is used as the required braking air pressure.

In some embodiments, when the trailer turns rapidly, the tipping state is too large, and rollover is very likely to occur, and at this time, if braking is performed only by a braking signal of the tractor, a great potential safety hazard occurs. At the moment, the braking air pressure required by the trailer is determined according to rollover prevention, and the rollover prevention determination process is as follows:

when a sensor built in the trailer detects that the lateral acceleration of the trailer at the target moment is larger than a preset acceleration threshold value, a rollover prevention signal is sent out.

At this time, the rollover prevention signal and the anti-lock signal sent by the trailer are received at the same time, and the braking air pressure corresponding to rollover prevention and the braking air pressure corresponding to anti-lock are different, so that a final braking air pressure needs to be arbitrated, and the running safety is ensured. The procedure for determination is as follows:

And when the rollover prevention signal and the anti-lock signal sent by the trailer are received at the same time, taking the fourth braking air pressure corresponding to the anti-lock signal at the target moment as the required braking air pressure. When rollover is prevented, the air pressures of the left and right vehicles are different. The fourth brake air pressure includes a fourth left brake air pressure and a fourth right brake air pressure, and the fourth left brake air pressure and the fourth right brake air pressure are different.

When the anti-lock signal disappears, the fifth braking air pressure of the trailer at the moment is determined based on the received anti-rollover signal, and the fifth braking air pressure is used as the required braking air pressure.

In some embodiments, because of the complex coupling relationship between the tractor and the trailer of the heavy semi-trailer tractor, the rear part of the tractor is amplified, and rollover accidents are very easy to occur in the driving process. Under certain limiting conditions, when the driver steps on the brakes, the trailer receives a braking signal sent by the tractor. At this time, the braking air pressure required by the trailer is also required to be determined according to rollover prevention, and the rollover prevention determination process is as follows:

when a sensor built in the trailer detects that the lateral acceleration of the trailer at the target moment is larger than a preset acceleration threshold value, a rollover prevention signal is sent out.

At this time, the braking signal sent by the tractor and the rollover prevention signal sent by the trailer are received at the same time, and the braking air pressure corresponding to the braking signal and the braking air pressure corresponding to rollover prevention are different, so that a final braking air pressure needs to be arbitrated, and the running safety is ensured. The procedure for determination is as follows:

when a braking signal sent by the tractor and an anti-rollover signal sent by the trailer are received at the same time, taking the sixth braking air pressure corresponding to the anti-rollover signal at the target moment as the required braking air pressure. When rollover is prevented, the air pressures of the left and right vehicles are different. The sixth brake air pressure includes a sixth left brake air pressure and a sixth right brake air pressure, and the sixth left brake air pressure and the sixth right brake air pressure are different.

When the rollover prevention signal disappears, the seventh braking air pressure of the trailer at the moment is determined based on the received braking signal sent by the tractor, and the seventh braking air pressure is used as the required braking air pressure.

In some embodiments, in addition to the acquisition of the required braking air pressure at the target time, the braking type corresponding to the required braking air pressure may also be acquired. Such as setting an activation flag bit and an activation state corresponding to the demanded brake air pressure. The activation flag bit is any one of normal braking, anti-lock braking or rollover prevention, and the activation state is used for indicating the working state of any one of working states, such as working or non-working.

When only a braking signal sent by the tractor is received, an activation zone bit of conventional braking is sent out, and the activation state of the activation zone bit of the conventional braking is a working state.

When the braking signal sent by the tractor and the anti-lock signal sent by the trailer are received at the same time, the anti-lock activation flag bit is sent, and the activation state of the anti-lock activation flag bit is the working state.

When the rollover prevention signal and the anti-lock signal sent by the trailer are received at the same time, an anti-lock activation flag bit is sent, and the activation state of the anti-lock activation flag bit is a working state.

When a braking signal sent by the tractor and an anti-rollover signal sent by the trailer are received at the same time, an anti-rollover activation zone bit is sent out, and the activation state of the anti-rollover activation zone bit is a working state.

Step S120, determining the energizing time and the duty ratio of the electromagnetic valve on the trailer based on the actual braking air pressure and the required braking air pressure.

The pressure closed-loop control can be realized through the collected actual braking air pressure and the required braking air pressure, and the braking control can be realized through controlling the energizing time and the duty ratio of the electromagnetic valve.

The hanging wheel has three air pressure states of pressurization, pressure relief and pressure maintaining. The trailer electronic control module can determine the air pressure state at the next moment according to the actual braking air pressure and the required braking air pressure, and then the bridge control modules arranged on the left side and the right side of the trailer are adjusted to adjust the air pressure.

The bridge control modules comprise an air inlet electromagnetic valve, an air outlet electromagnetic valve, a standby electromagnetic valve, a relay electromagnetic valve and a pressure sensor, and the bridge control modules at the left side and the right side are identical, so that independent control of left side pressure and right side pressure can be realized.

The control air path channel of the bridge control module is shown in fig. 2, the air inlet 11 is connected with an air source, and the air outlet 21 is connected with a brake air chamber or next equipment. The exhaust port 31 is connected to the atmosphere, and the backup port 41 is connected to the backup circuit control. The gas from the inlet 11 sequentially passes through an inlet electromagnetic valve and an outlet electromagnetic valve, which are normally closed valves. A pressure sensor is arranged below the air inlet 11 and can feed back the actual pressure of the brake chamber so as to achieve pressure closed-loop control. The relay solenoid valve is arranged above the air outlet 21 and is close to the braking air chamber, and the relay solenoid valve is opened to be communicated with the air inlet 11 and the air outlet 21, so that air can quickly enter the air chamber.

In some embodiments, pressurization is required when the demanded brake air pressure is greater than the actual brake air pressure. The air flow direction at this time is from the air inlet to the brake chamber, and the air inlet solenoid valve is energized and opened, and the air outlet solenoid valve is not energized and remains closed. After the air inlet electromagnetic valve is electrified, air passes through the air inlet electromagnetic valve to reach the upper end of the relay electromagnetic valve, the spring is pressed down under the action of pressure difference to enable the relay electromagnetic valve to be opened, and the air rapidly enters into the brake air chamber from the air inlet through the relay electromagnetic valve. The energization time and the opening duty cycle of the intake solenoid valve determine the pressure of the gas reaching the upper end of the relay solenoid valve, i.e., the relay solenoid valve opening, thereby affecting the final pressurization pressure.

In this embodiment, in order to increase the speed of the increase in the air pressure, the duty ratio of the intake solenoid valve needs to be set on a case-by-case basis. When the difference between the required brake air pressure and the actual brake air pressure is large, the pressure needs to be quickly increased, and the target required pressure is reached with a large pressurizing slope. And when the difference between the required brake air pressure and the actual brake air pressure is small, the pressurization can be performed with a small pressurization slope.

For example, when the demanded brake air pressure is greater than the actual brake air pressure and when the differential pressure is greater than a first preset differential pressure threshold, the intake solenoid valve is continuously energized and the duty cycle of the intake solenoid valve is set to a first duty cycle. When the pressure difference is larger than the first preset pressure difference threshold value, the air inlet electromagnetic valve needs to be driven to work at a larger duty ratio, for example, the first duty ratio can be set to be 90% -100%. During pressurization, the air pressure in the brake chamber needs to be monitored in real time. When the pressure difference between the required braking air pressure and the real-time air pressure in the braking air chamber is monitored to be smaller than a first preset pressure difference threshold value, the pressure can be increased with a smaller pressurizing slope, the air inlet solenoid valve duty ratio is set to be a second duty ratio, and the power supply is stopped when the pressure difference is monitored to be equal to the second preset pressure difference threshold value. For example, the second duty cycle may be set to 30% -80%. The second preset pressure difference threshold may be 0, and when the pressure difference is detected to be 0, the energization is stopped, and the pressurization is completed.

In some embodiments, pressure relief is required when the demanded brake air pressure is less than the actual brake air pressure. During pressure relief, the direction of gas flow is from the brake chamber to the exhaust port. The air inlet electromagnetic valve is not electrified and kept in a closed state, and the air outlet electromagnetic valve is electrified and opened. The exhaust electromagnetic valve is electrified to open the gas to reach the upper end of the relay electromagnetic valve from the brake air chamber, the spring is pressed down under the action of the pressure difference, the relay electromagnetic valve is opened, and the gas rapidly passes through the relay electromagnetic valve from the brake air chamber to reach the exhaust port and is discharged into the atmosphere. The energizing time and the opening duty ratio of the exhaust solenoid valve determine the pressure reaching the upper end of the relay solenoid valve, namely, the opening degree of the relay solenoid valve is determined so as to influence the volume of gas entering the atmosphere from the brake chamber, and finally, the gas pressure is determined.

In this embodiment, when the demanded brake air pressure is smaller than the actual brake air pressure and the absolute value of the differential pressure is larger than the third preset differential pressure threshold, the exhaust solenoid valve is required to operate at a larger duty ratio at this time, so as to increase the pressure release speed. For example, when the demanded brake air pressure is less than the actual brake air pressure and the absolute value of the differential pressure is greater than a third preset differential pressure threshold, the exhaust solenoid valve is set to be continuously energized and the duty cycle of the exhaust solenoid valve is the first duty cycle, and energization is stopped when the differential pressure is monitored to be equal to a fourth preset differential pressure threshold, the third preset differential pressure threshold being greater than the fourth preset differential pressure threshold.

For example, when the actual brake air pressure is equal to 0, the pressure difference between the demanded brake air pressure and the actual brake air pressure is large, and full pressure relief is performed, and at this time, the exhaust solenoid valve needs to be opened at a large duty ratio, such as a duty ratio of 90% -100%. When the air pressure in the brake air chamber is monitored to be equal to 0, the power supply is stopped, and the exhaust electromagnetic valve stops working.

In this embodiment, when the demanded brake air pressure is smaller than the actual brake air pressure and the absolute value of the differential pressure is smaller than the fifth preset differential pressure threshold, the pressure relief may be performed, the exhaust solenoid valve is set to be continuously energized and the duty ratio of the exhaust solenoid valve is set to be the second duty ratio, and the energization is stopped when the differential pressure is monitored to be equal to the fourth preset differential pressure threshold, the fifth preset differential pressure threshold being larger than the fourth preset differential pressure threshold.

For example, when the demanded brake air pressure is smaller than the actual brake air pressure and the absolute value of the differential pressure is smaller than the fifth preset differential pressure threshold value, the pressure relief can be performed at a smaller pressure relief rate due to the smaller differential pressure at this time. The vent solenoid valve may be opened, for example, at a duty cycle of 30% -80%. And when the monitored air pressure in the brake air chamber is equal to the required brake air pressure, stopping electrifying, and stopping the work of the exhaust electromagnetic valve.

In some embodiments, when the demanded brake air pressure is equal to the actual brake air pressure, neither the exhaust solenoid valve nor the intake solenoid valve is energized to maintain a closed state, while maintaining the pressure.

And step S130, adjusting the braking air pressure of the trailer according to the energizing time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer.

After the power-on time and the duty ratio of the exhaust electromagnetic valve or the air inlet electromagnetic valve are determined, the bridge control modules at the two ends of the trailer can adjust the braking air pressures at the left side and the right side of the trailer according to the power-on time and the duty ratio of the exhaust electromagnetic valve or the air inlet electromagnetic valve, so that the braking strength of the trailer is changed.

According to the control method for braking the trailer, firstly, the actual braking air pressure and the required braking air pressure of the trailer at the target moment are obtained, then the power-on time and the duty ratio of the electromagnetic valve on the trailer are determined based on the actual braking air pressure and the required braking air pressure, and finally, the braking air pressure of the trailer is adjusted according to the power-on time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer. According to the invention, the trailer electric control equipment is arranged on the trailer, so that the trailer is braked by means of a braking signal sent by the tractor, and a final required braking air pressure is determined according to an anti-rollover signal or an anti-lock signal sent by the trailer, so that the power-on time and the duty ratio of an electromagnetic valve on the trailer are determined according to the required braking air pressure and the actual detected braking air pressure. The braking of the trailer in the running process is not only simply dependent on the braking sent by the tractor, but also the proper required braking air pressure is determined based on the actual running condition of the wheel hanging end, so that the braking performance of the trailer is improved, and the driving safety is further improved.

It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present invention.

Based on the control method of the trailer braking provided by the embodiment, correspondingly, the invention also provides a specific implementation mode of the control device of the trailer braking, which is applied to the control method of the trailer braking. Please refer to the following examples.

As shown in fig. 3, there is provided a control device 300 for trailer braking, the device comprising:

the air pressure obtaining module 310 is configured to obtain an actual braking air pressure and a required braking air pressure of the trailer at a target moment, where the required formulated air pressure is determined according to at least one of a braking signal sent by the tractor, an anti-lock signal sent by the trailer, and an anti-rollover signal sent by the trailer;

a determine duty cycle module 320 for determining an energization time and a duty cycle of a solenoid valve on the trailer based on the actual brake air pressure and the demanded brake air pressure;

the adjusting module 330 is used for adjusting the braking air pressure of the trailer based on the energizing time and the duty cycle of the electromagnetic valve so as to change the braking strength of the trailer.

In one possible implementation, the air pressure obtaining module 310 is configured to determine, when only the braking signal sent by the tractor is received, a first braking air pressure of the trailer at the target moment based on the braking signal sent by the tractor, and take the first braking air pressure as the required braking air pressure;

when a braking signal sent by a tractor and an anti-lock signal sent by a trailer are received at the same time, taking second braking air pressure corresponding to the anti-lock signal at a target moment as required braking air pressure; when the anti-lock signal disappears, determining third braking air pressure of the trailer at the moment based on the received braking signal sent by the tractor, and taking the third braking air pressure as required braking air pressure;

when the rollover prevention signal and the anti-lock signal sent by the trailer are received at the same time, fourth braking air pressure corresponding to the anti-lock signal at the target moment is used as required braking air pressure; when the anti-lock signal disappears, determining fifth braking air pressure of the trailer at the moment based on the received anti-rollover signal, and taking the fifth braking air pressure as required braking air pressure;

when a braking signal sent by a tractor and an anti-rollover signal sent by a trailer are received at the same time, taking a sixth braking air pressure corresponding to the anti-rollover signal at a target moment as a required braking air pressure; when the rollover prevention signal disappears, the seventh braking air pressure of the trailer at the moment is determined based on the received braking signal sent by the tractor, and the seventh braking air pressure is used as the required braking air pressure.

In one possible implementation, the air pressure obtaining module 310 is configured to determine the first braking air pressure of the trailer at the target time based on the braking demand air pressure in the braking signal sent by the tractor at the target time, the load distribution of the tractor and the trailer, and the speeds of the tractor and the trailer at the target time, respectively.

In one possible implementation, the air pressure module 310 is configured to determine a slip ratio of the trailer based on a speed of the trailer at a target time and a wheel speed of the trailer; when the slip rate is greater than the slip rate threshold, an anti-lock signal is sent out;

the air pressure obtaining module 310 is configured to send out a rollover prevention signal when it is detected that the lateral acceleration of the trailer at the target moment is greater than a preset acceleration threshold.

In one possible implementation, the determining duty cycle module 320 is configured to, when the demanded brake air pressure is greater than the actual brake air pressure, set the intake solenoid valve to be continuously energized and the duty cycle of the intake solenoid valve to be the first duty cycle when the differential pressure is greater than a first preset differential pressure threshold; when the pressure difference is monitored to be smaller than a first preset pressure difference threshold value, setting the duty ratio of the air inlet electromagnetic valve as a second duty ratio, and stopping electrifying when the pressure difference is monitored to be equal to the second preset pressure difference threshold value; the differential pressure is the difference between the required braking air pressure and the actual braking air pressure, the first preset differential pressure threshold value is larger than the second preset differential pressure threshold value, and the first duty ratio is larger than the second duty ratio;

When the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is larger than a third preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is the first duty ratio, and the electrification is stopped when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value;

when the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is smaller than a fifth preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is set to be a second duty ratio, and the electrification is stopped when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value; the third preset differential pressure threshold value is larger than the fifth preset differential pressure threshold value, and the fifth preset differential pressure threshold value is larger than the fourth preset differential pressure threshold value.

In one possible implementation, the trailer receives a brake signal sent by the tractor through a CAN signal line;

bridge control modules are arranged on the left side and the right side of the trailer, and an air inlet electromagnetic valve, an air outlet electromagnetic valve and a pressure sensor are arranged in the bridge control modules and are used for monitoring the actual pressure in the brake air chamber in real time;

the second brake air pressure includes a second left brake air pressure and a second right brake air pressure, and the second left brake air pressure and the second right brake air pressure are different; the fourth brake air pressure includes a fourth left brake air pressure and a fourth right brake air pressure, and the fourth left brake air pressure and the fourth right brake air pressure are different; the fifth brake air pressure includes a fifth left brake air pressure and a fifth right brake air pressure, and the fifth left brake air pressure and the fifth right brake air pressure are different; the sixth brake air pressure includes a sixth left brake air pressure and a sixth right brake air pressure, and the sixth left brake air pressure and the sixth right brake air pressure are different.

Fig. 4 is a schematic diagram of a trailer electronic control device according to an embodiment of the present invention. As shown in fig. 4, the trailer electronic control apparatus 4 of this embodiment includes: a processor 40, a memory 41 and a computer program 42 stored in the memory 41 and executable on the processor 40. The processor 40, when executing the computer program 42, implements the steps of the various embodiments of the trailer brake control method described above, such as steps 110 through 130 shown in fig. 1. Alternatively, the processor 40, when executing the computer program 42, performs the functions of the modules of the apparatus embodiments described above, such as the functions of the modules 310-330 shown in fig. 3.

Illustratively, the computer program 42 may be partitioned into one or more modules that are stored in the memory 41 and executed by the processor 40 to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing the specified functions, which instruction segments describe the execution of the computer program 42 in the electronic device 4. For example, the computer program 42 may be partitioned into modules 310 through 330 shown in FIG. 3.

The trailer electronic control apparatus 4 may include, but is not limited to, a processor 40, a memory 41. It will be appreciated by those skilled in the art that fig. 4 is merely an example of the trailer electronic control device 4 and is not meant to be limiting of the trailer electronic control device 4, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., the electronic device may also include an input-output device, a network access device, a bus, etc.

The processor 40 may be a central processing unit (Central Processing Unit, CPU), other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field-programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 41 may be an internal storage unit of the electronic device 4, such as a hard disk or a memory of the trailer electronic control device 4. The memory 41 may be an external storage device of the electronic device 4, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the electronic device 4. Further, the memory 41 may also comprise both an internal memory unit and an external memory unit of the trailer electronic control device 4. The memory 41 is used for storing the computer program and other programs and data required by the electronic device. The memory 41 may also be used for temporarily storing data that has been output or is to be output.

In addition, the embodiment of the application also provides a semi-trailer traction vehicle, as shown in fig. 5, the semi-trailer traction vehicle 5 comprises a tractor and a trailer, and the trailer is provided with the trailer electric control equipment 4.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/electronic device and method may be implemented in other manners. For example, the apparatus/electronic device embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical function division, and there may be additional divisions in actual implementation, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated modules/units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the present invention may be implemented in whole or in part by a computer program to instruct related hardware to perform the above-described embodiment method, and the computer program may be stored in a computer readable storage medium, where the computer program, when executed by a processor, may implement the steps of the above-described embodiment method for controlling braking of a trailer. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer Memory, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth.

The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention, and are intended to be included in the scope of the present invention.

Claims (10)

1. The control method for braking of the trailer is characterized in that the trailer is provided with trailer electric control equipment for controlling the braking of the trailer, and the control method comprises the following steps:

acquiring actual braking air pressure and required braking air pressure of the trailer at a target moment, wherein the required formulated air pressure is determined according to at least one of a braking signal sent by a tractor, an anti-lock signal sent by the trailer or an anti-rollover signal sent by the trailer;

determining an energization time and a duty cycle of a solenoid valve on the trailer based on the actual brake air pressure and the demanded brake air pressure;

And adjusting the braking air pressure of the trailer according to the energizing time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer.

2. The control method of claim 1, wherein the obtaining the demanded brake air pressure of the trailer at the target time comprises:

when only a braking signal sent by a tractor is received, determining first braking air pressure of the trailer at a target moment based on the braking signal sent by the tractor, and taking the first braking air pressure as the required braking air pressure;

when a braking signal sent by the tractor and an anti-lock signal sent by the trailer are received at the same time, taking second braking air pressure corresponding to the anti-lock signal at a target moment as the required braking air pressure; when the anti-lock signal disappears, determining third braking air pressure of the trailer at the moment based on a received braking signal sent by the tractor, and taking the third braking air pressure as the required braking air pressure;

when an anti-rollover signal and an anti-lock signal sent by the trailer are received at the same time, taking fourth braking air pressure corresponding to the anti-lock signal at a target moment as the required braking air pressure; when the anti-lock signal disappears, determining fifth braking air pressure of the trailer at the moment based on the received anti-rollover signal, and taking the fifth braking air pressure as the required braking air pressure;

When a braking signal sent by the tractor and an anti-rollover signal sent by the trailer are received at the same time, taking a sixth braking air pressure corresponding to the anti-rollover signal at a target moment as the required braking air pressure; when the rollover prevention signal disappears, determining a seventh braking air pressure of the trailer at the moment based on a received braking signal sent by the tractor, and taking the seventh braking air pressure as the required braking air pressure.

3. The control method of claim 2, wherein the determining a first brake air pressure of the trailer at a target time based on the brake signal sent by the tractor comprises:

the first brake air pressure of the trailer at the target moment is determined based on brake demand air pressure in a brake signal sent by the tractor at the target moment, load distribution of the tractor and the trailer, and speeds of the tractor and the trailer at the target moment respectively.

4. The control method according to claim 2, wherein the determination process of the anti-lock signal is:

determining a slip ratio of the trailer based on a vehicle speed of the trailer at a target time and a wheel speed of the trailer; when the slip rate is greater than a slip rate threshold, an anti-lock signal is sent out;

The determination process of the rollover prevention signal comprises the following steps:

and when the lateral acceleration of the trailer at the target moment is detected to be larger than a preset acceleration threshold value, sending out a rollover prevention signal.

5. The control method of claim 1, wherein the determining the energization time and the duty cycle of the solenoid valve on the trailer based on the actual brake air pressure and the required brake air pressure comprises:

when the required braking air pressure is larger than the actual braking air pressure, when the pressure difference is larger than a first preset pressure difference threshold value, the air inlet electromagnetic valve is set to be electrified continuously, and the duty ratio of the air inlet electromagnetic valve is a first duty ratio; when the pressure difference is monitored to be smaller than the first preset pressure difference threshold value, setting the duty ratio of the air inlet electromagnetic valve to be a second duty ratio, and stopping electrifying when the pressure difference is monitored to be equal to the second preset pressure difference threshold value; the first preset differential pressure threshold value is larger than the second preset differential pressure threshold value, and the first duty ratio is larger than the second duty ratio;

when the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is larger than a third preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is the first duty ratio, and when the pressure difference is monitored to be equal to a fourth preset pressure difference threshold value, the electrification is stopped;

When the required braking air pressure is smaller than the actual braking air pressure and the absolute value of the pressure difference is smaller than a fifth preset pressure difference threshold value, the exhaust electromagnetic valve is set to be electrified continuously, the duty ratio of the exhaust electromagnetic valve is the second duty ratio, and when the pressure difference is monitored to be equal to the fourth preset pressure difference threshold value, the electrification is stopped; wherein the third preset differential pressure threshold is greater than the fifth preset differential pressure threshold, which is greater than the fourth preset differential pressure threshold.

6. The control method of any one of claims 2-4, wherein the trailer receives a brake signal sent by the tractor via a CAN signal line;

bridge control modules are arranged on the left side and the right side of the trailer, an air inlet electromagnetic valve, an air outlet electromagnetic valve and a pressure sensor are arranged in the bridge control modules, and the pressure sensor is used for monitoring the actual pressure in a brake air chamber in real time;

the second brake air pressure includes a second left brake air pressure and a second right brake air pressure, and the second left brake air pressure and the second right brake air pressure are different; the fourth brake air pressure includes a fourth left brake air pressure and a fourth right brake air pressure, and the fourth left brake air pressure and the fourth right brake air pressure are different; the fifth brake air pressure includes a fifth left brake air pressure and a fifth right brake air pressure, and the fifth left brake air pressure and the fifth right brake air pressure are different; the sixth brake air pressure includes a sixth left brake air pressure and a sixth right brake air pressure, and the sixth left brake air pressure and the sixth right brake air pressure are different.

7. A control device for braking a trailer, comprising:

the system comprises an air pressure acquisition module, an air pressure generation module and a control module, wherein the air pressure acquisition module is used for acquiring the actual braking air pressure and the required braking air pressure of the trailer at a target moment, and the required formulated air pressure is determined according to at least one signal of a braking signal sent by a tractor, an anti-lock signal sent by the trailer or an anti-rollover signal sent by the trailer;

the determining duty ratio module is used for determining the energizing time and the duty ratio of the electromagnetic valve on the trailer based on the actual braking air pressure and the required braking air pressure;

and the adjusting module is used for adjusting the braking air pressure of the trailer based on the energizing time and the duty ratio of the electromagnetic valve so as to change the braking strength of the trailer.

8. An electrically controlled device for a trailer, comprising a memory for storing a computer program and a processor for calling and running the computer program stored in the memory for performing the method according to any one of claims 1 to 7.

9. A semi-trailer traction vehicle comprising a tractor and a trailer, said trailer having mounted thereon the trailer electrical control apparatus as claimed in claim 8.

10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of the method according to any one of claims 1 to 7.