WO2017100891A1

WO2017100891A1 - Method for controlling a switching-off and starter device for the internal combustion engine of a heavy-weight vehicle, and said device

Info

Publication number: WO2017100891A1
Application number: PCT/BR2016/050324
Authority: WO
Inventors: Thomas Junge; Filipe SILVA; Thiago MALICHESKI
Original assignee: Robert Bosch Limitada
Priority date: 2015-12-17
Filing date: 2016-12-13
Publication date: 2017-06-22
Also published as: BR102015031645B1; CL2018001642A1; PE20181813A1; BR102015031645A2; ZA201804754B

Abstract

The present invention pertains to the technical field of heavy-weight utility vehicles. The invention relates to a method for controlling a switching-off and starter device (7) for the internal combustion engine (2) of a heavy-weight vehicle (1), the method comprising the following steps: — completing a first brake control sequence (S1a) during which a parking brake (23) of the vehicle (1) is enabled; — completing a second brake control sequence (S1b) during which a stopping brake (22) of the vehicle (1) is disabled; — switching-off the internal combustion engine (2). The present invention also relates to a switching-off and starter device (7) for the internal combustion engine (2) of a heavy-weight vehicle (1).

Description

DETAILED DESCRIPTION REPORT FOR THE PROCESS OF CONTROL OF A HEAVY VEHICLE ENGINE COMBUSTION AND STARTING DEVICE This invention relates to the technological field of combustion engine vehicles fitted with stop and start devices capable of automatically switching off the combustion engine when the vehicle is stationary and restarting it when necessary. Combustion engine shutdown and starting devices generate considerable fuel savings, especially in heavy duty vehicles, and reduce the level of environmental pollution.

[002] The invention is intended precisely for vehicles used in situations where a high level of operational safety is required.

Description of the prior art

[003] Document W015075526 describes a vehicle equipped with an electronic parking brake and a main brake maintenance system. This vehicle includes a stop and start device that, when the engine is turned off, locks the vehicle with the main brake maintenance system and, after a while, engages the electronic parking brake.

[004] The system described works on standard vehicles but is not adapted to specific situations where high levels of operational safety are required, as may be the case for heavy duty vehicles operating in hazardous areas.

Brief Description of the Invention

The purpose of the present invention is to improve known processes and devices with respect to operational safety. Indeed, the invention relates to a method of controlling a shutdown and starting device for the combustion engine of a heavy vehicle, including the steps of automatically shutting down the combustion engine when shutdown conditions are met and of automatically start the combustion engine when starting conditions are met. The process comprises the following steps:

- continuously monitor a set of parameters to determine if shutdown conditions are met;

- perform a first brake control sequence in which a vehicle parking brake is activated;

- add a parking brake activation parameter to the parameter set being monitored;

- perform a second brake control sequence in which a vehicle lock brake is deactivated;

- add a parameter related to the lock brake deactivation to the parameter set being monitored;

- switch off the combustion engine.

[007] Another object of the invention is a combustion engine starting and stopping device for a heavy vehicle, implementing the process as described above, and including:

- a shutdown and start control unit;

- an independent vehicle parking brake control, actuated by the start and stop control unit;

- an independent vehicle lock brake control, actuated by the shutdown and start control unit.

Heavy-duty vehicles such as semi-trailers, mining, construction, forestry, or agricultural trucks, etc., have their own weight high, also usually carry large loads. For example, a typical mining truck has its own weight of around 200 tons and, under load, can reach a total weight of around 500 tons. Such vehicles require exceptional operational safety measures, as any failure in the systems used to immobilize the vehicle can result in extraordinary moving weights causing uncontrollability causing great danger to the operator.

In these vehicles equipped with an automatic shut-off and start-up device, the issue of operational safety is of prime importance.

[0010] The invention guarantees maximum safety in the operation of the shutdown and start device. In addition to the automatic shutdown and starting of the combustion engine, the shutdown and starting device also manages the brakes so that they are integrated with safety checks.

[001 1] If the parking brake is faulty after the first brake control sequence, that fault is revealed by the shutdown and start device that monitors all parameters related to shutdown conditions. Likewise, if the locking brake fails after the second brake control sequence, that failure is also revealed by the shutdown and start device.

Because the lock brake uses the same hydraulic circuit as the vehicle's main service brake, lock brake monitoring is equivalent to monitoring the main brake.

In fact, the invention allows, in addition to the safety of automatic shutdown and start operations, the monitoring of all vehicle brakes at each operation of the shutdown and start device. With continuous monitoring of the parameters related to the shutdown conditions, to which the parameters related to the brakes are successively added one by one, providing maximum operational safety. The method and the device according to the invention ensure that when the engine is automatically shut off, the brakes are in the right position, ie the parking brake already activated and the locking brake deactivated. This allows the vehicle to be safely locked (parking brake) and ensuring that it is not engaged with another brake, which would result in risks of interference and useless hydraulic circuit under pressure.

These safety measures allow the use of the shut-off and start-up device on vehicles such as heavy-duty vehicles, which pose a risk if they are not stopped when the engine is stopped. Such vehicles, which usually require strict safety procedures to be performed by the driver with respect to the brakes when starting or stopping the engine, may benefit if equipped with the invention which assumes that such procedures are performed automatically.

Preferred features which may complement the process or device according to the invention are set forth below. The process or device may include one of these characteristics or a combination of these characteristics.

[0017] The first brake control sequence includes checking that the parking brake is properly activated.

If the parking brake is found to be deactivated, the process comprises an additional step of activating the parking brake.

[0019] The second brake control sequence includes verifying that the lock brake is properly deactivated. [0020] The process comprises an additional step of deactivating the lock brake if it is found that the lock brake is activated.

If the parking brake is deactivated after the first brake control sequence, the combustion engine is prevented from stopping automatically.

If the parking brake is disabled after the first brake control sequence, a fault is signaled to the vehicle driver.

[0023] If the parking brake is disabled after the first brake control sequence, a parking brake failure is signaled on a vehicle network bus.

If the lock brake is activated after the second brake control sequence, the combustion engine is prevented from automatically stopping.

If the lock brake is disabled after the second brake control sequence, a fault is signaled to the vehicle driver.

If the lock brake is activated after the second brake control sequence, a lock brake failure is signaled on a vehicle network bus.

[0027] The parking brake is activated or deactivated regardless of its manual activation.

After the combustion engine shutdown step, the process includes a step of activating lights external to the vehicle for automatic shutdown signaling.

After the step of turning off the combustion engine, The process includes a step of automatically starting the combustion engine when starting conditions are met, and then a step in which the parking brake control is returned to the driver of the machine, ie according to the parking brake manual actuation.

[0030] The process further comprises a step in which the lock brake control is returned to the machine driver, ie according to the manual lock brake actuation.

The process includes a step of signaling to the driver of the vehicle about returning the parking brake or locking to its starting position.

[0032] These verified starting conditions include activation of the main brake pedal by the driver of the vehicle.

The device also includes external lights for automatic shutdown signaling.

Brief Description of the Figures

The invention is detailed below by the description of a preferred embodiment, exemplified by the figures, in which:

Figure 1 illustrates a vehicle equipped with a shutdown and start device according to the invention;

Figure 2 schematically illustrates the disconnecting and starting device fitted to the vehicle of Figure 1;

Figure 3 is a state diagram of the device of Figure 2;

Figures 4 to 7 are flowcharts detailing the states of the diagram of Figure 3.

Detailed Description of the Figures

Figure 1 shows an example of a vehicle implementing the invention. In this embodiment, vehicle 1 is a heavy duty vehicle used to carry important loads.

Vehicle 1 comprises a combustion engine 2 for its propulsion and a cargo transport bucket 3. The driver is situated in a cabin 4 where he is protected. [0037] The combustion engine 2 has an automatic shutdown and start function that allows fuel to be saved when vehicle 1 is stopped. However, this function is subject to situations considered to be highly critical as automatic engine shutdown or starting at an inconvenient time can cause serious safety problems.

The shutdown and start function is therefore included in an embodiment of the invention focused on maximum operational safety. Figure 2 represents a control system 5 of combustion engine 2 that includes this function.

The combustion engine control system 5 comprises an engine control device 6 (represented by the dashed frame in the left part of figure 2) and a shutdown and start device 7 (represented by the dashed frame in the right part of the figure 2).

Engine control device 6 includes an engine control unit 8 ("Engine Control Unif) and a vehicle control unit 9 {" Machine Control Unif) respectively connected to an engine sensor assembly 10 and a vehicle sensor array 1 1.

As usual, the motor sensor assembly 10 includes sensors such as: temperature sensors, speed sensors, lubricant level sensors, etc. to enable engine control unit 8 to manage the operation of the combustion engine 2.

Vehicle Sensor Set 1 1 includes sensors such as driver presence sensors, door sensors, brake sensors, etc. to enable vehicle control unit 9 to manage vehicle operation 1 except combustion engine 2. Motor control unit 8 and vehicle control unit 9 are connected via a network bus 12. The network bus 12 can be, for example, a CAN ("Controller Area Network") bus. which is common in automotive production.

Vehicle control unit 9 is also connected with the three types of vehicle 1 brakes, namely: a main brake 21; a locking brake 22; and a parking brake 23.

[0045] The main brake 21 is the usual service brake used during vehicle travel 1 and which the driver applies with the pedal. A vehicle 1 master brake pedal sensor 21 is monitored by the start and stop control unit 15 to determine whether or not the brake is activated. The main brake pedal sensor 21 may be a sensor indicating that the driver has depressed the pedal, or a pressure sensor indicating a pressure rise in the brake hydraulic circuit, or any other sensor capable of informing that the driver is activating the brake. principal 21.

The locking brake 22 is a device that locks one or more front wheels or one or more rear wheels that the driver can engage to immobilize vehicle 1 during a short stop.

Parking brake 23 is a brake that allows one or more vehicle 1 wheels to be locked permanently for extended vehicle stops 1.

The three types of brakes may involve hydraulic activation or deactivation devices intended for large vehicles used in heavy duty work. The locking brake 22 and the parking brake 23 are each activated by an electric actuation command located on the vehicle's dashboard 1.

The engine control device 6 further includes a starter motor 13 for starting the combustion engine 2 and an inlet of ignition signal 14, which is usually a key located on the dashboard and accessible to the driver. When the driver triggers the ignition signal 14, the starter 13 is driven and the engine control unit 8 controls the start of the combustion engine 2. Throughout this application, the term "starter" refers to a single starter motor or a starter motor set as it is usual for larger vehicles to use more than one starter motor.

The shutdown and start device 7 comprises in turn a shutdown and start control unit 15 which is a programmable logic controller designed to control the functions of the shutdown and start device 7, ie capable of: check when the conditions are met for automatic combustion engine shutdown 2 and automatic shutdown; and checking when the conditions are met for an automatic start of the combustion engine 2 and proceed with that automatic start.

Optionally, the start and stop control unit 15 includes a connection 19 with the ignition signal 14 and / or a connection 20 with the starter 13. According to this option, the stop and start device 7 may be supplied as a kit for mounting on an existing vehicle that is devoid of the automatic shutdown and start function. This kit can thus be installed and connected to the existing vehicle, the connection 19 with the ignition signal 14 and the connection 20 with the starter motor 13 allowing the stop and start device 7 to start the combustion engine 2.

Stop and start control unit 15 is connected to network bus 12 of vehicle 1 so that it can communicate with engine control unit 8 and vehicle control 9.

In order to perform the automatic shutdown and start function, the shutdown and start control unit 15 requires data provided by different sensors, both combustion engine 2 and vehicle 1, to be able to verify that the shutdown conditions or departure are satisfied. To this end, the start and stop control unit 15 communicates with engine control unit 8 and / or vehicle control unit 9 to access data from all sensors in engine sensor set 10 and of the vehicle sensor assembly 1 1.

The shutdown and start control unit 15 is also connected to a set of specific sensors 18 that are useful exclusively for the shutdown and start function such as, for example, a battery state detection system (to inhibit automatic shutdown of the combustion engine 2 if the battery is low).

Examples of the different sensors used by the shutdown and start control unit 15 will be given below, both from the engine sensor set 10 and from the vehicle sensor set 1 1, and from the specific sensor set 18.

The start and stop control unit 15 is further connected to: a stop and start contactor 24, allowing the driver to activate or deactivate the automatic stop and start function; an automatic shutdown and start interface 25, located on the dashboard visible to the driver and capable of indicating the operation of the shutdown and start device 7; auto-off signal lights 26 visible from the outside of the vehicle and indicating to other vehicles around that vehicle is having its engine switched off due to automatic shut-off. Figure 3 illustrates the sequence of operation of the shutdown and start control unit 15. Each frame S0 to S5 represents a possible state of the shutdown and start control unit 15 and each arrow T1 to T1 1 represents a possible transition. between these states.

Possible states are as follows:

- states S1 a and S1 b, which are shutdown enable states where the shutdown and start control unit 15, having verified that the automatic shutdown conditions are met, prepares the combustion engine 2 shutdown (state S1 a refers to a first brake control sequence and state S1 b refers to a second brake control sequence);

- state S2, which is the shutdown state of combustion engine 2;

- state S3, which is the state of engine off;

- state S4, which is the start enable state where the stop and start control unit 15, having verified that the automatic starting conditions are met, prepares the start of the combustion engine;

- state S5, which is the starting state, where starter motor 13 is activated;

- state S0, which is the state of the engine running.

[0059] To switch from running motor state S0 to trip enable state S1 a, it is necessary to go through transition T1 which, in this example, is performed only if all the following conditions are met with the relative sensors:

- lock brake 22 or parking brake 23 activated by the driver;

- Cabin door (s) 4 closed; - 4 cabin temperature lying within a certain range of comfort, for example 18 to 22 ^Q C ^Q C;

- combustion engine temperature 2 above a certain value, eg 70 ^Q C (indicating that the engine is hot);

- gear selector in neutral position;

- driver present in the seat;

- bucket 3 in rest position (indicating that the vehicle is not maneuvering with the bucket);

- combustion engine speed 2 between an operating range determined as idle, for example between 400 RPM and 1000 RPM (indicating that the engine is running at idle);

- ambient temperature above a certain value, for example -10 ^Q C;

- downtime exceeding a certain value, eg two minutes (to prevent automatic shutdown of combustion engine 2 for vehicle stops of less than two minutes);

- no fault signal activated (engine alert or vehicle alert for whatever reason);

- stop and start contactor 24 activated (indicating that the driver requires the auto stop and stop function);

- driver's seat belt fitted;

- any engine turbocharger below a certain temperature;

- starter motor 13 operational;

- batteries sufficiently charged to power the starter motor and subsequently start the combustion engine 2; - slope of the ground less than a certain angle, eg 3 ^Q ;

- vehicle speed 1 null.

In the event that all of these conditions are met, transition T1 is performed and shutdown and start control unit 15 goes to state S1 a. Transition T1 means that automatic shutdown of the combustion engine is permitted. However, according to the invention, automatic shutdown is not performed at that time, but is postponed until after two brake control sequences are performed in shutdown enable states S1 a and S1 b. Delaying combustion engine shutdown 2 after brake control sequences ensures that vehicle 1, before shutting down engine 2, is in a state determined to be the safest, that is, with the parking brake 23 on, with the lock brake 22 off, and the position of these two brakes 22, 23 being monitored along with the other shutdown conditions.

[0061] Figure 4 represents the operations performed in state S1 a relative to a first brake control sequence. This state is opened by an initiation step E1 that happens shortly after the T1 transition is performed.

In step E2, a CT1 counter is started as follows: CT1 = 0.

[0063] In step E3, parking brake 23 is activated by the shutdown and start control unit 15, regardless of whether or not it has been activated by the driver. According to the present embodiment, the parking brake 23 by the shutdown and start control unit 15 is actuated by an independent control, i.e. through a device such as a parallel mounted relay of the control. parking brake 23 (the command that is available to the driver on the vehicle dashboard 1) so that the parking brake 23 can be independently controlled by the shutdown and start control unit 15. This provides additional safety in activation parking brake 23.

Step E4 is an interval step that stops the process for the time required for the parking brake 23 to be engaged because of the inertia of the mechanical and hydraulic systems. In the present example this time may be two seconds.

[0065] Step A1 is a first alternative step where the start and stop control unit 15 controls the pressure in the parking brake hydraulic circuit 23 to verify that this pressure is greater than a set pressure, indicating that the brake The parking space 23 is properly activated by means of sensors from the vehicle sensor assembly 1 1. If this is not the case, a new E5 interval step, which may be two seconds, follows step A1. Then, in an alternative step A2, it is checked that the CT1 counter is equal to 1, otherwise the process performs a second pass through steps E3, E4, and A1, after incrementing the CT1 counter in step E6

This allows a second attempt to activate parking brake 23 if it is not detected in step A1. After the second attempt, if it is found in step A1 that the parking brake 23 is not yet activated, the process goes back to step A2, where it turns out that the counter CT1 is this time equal to 1, which directs the process to failure step E7.

[0067] In step E7, the process completes with failure and the shutdown and start control unit 15 signals this fault via bus 12 to motor control unit 8 or motor control unit 9, which can then take safety measures regarding the fact that the parking brake 23 does not respond to the activation request. Passing the process through fault step E7 has as a first consequence inhibiting the shutdown and start function so that the shutdown and start control unit 15 no longer automatically shuts off the combustion engine 2. This fault step E7 can also initiate a parking brake failure signal 23 to the driver by means of a visual or audible signal.

Returning to step A1, if the activation of parking brake 23 is checked, the process goes to step E8 where counter CT1 is incremented (CT1 = CT1 +1) and goes to step E9 of waiting conditions. parking brake 23 being properly activated.

From step E9 of state S1 a, two transitions may occur: T8 or T2.

Transition T8, which leads back to state S0, is the reverse transition from transition T1. Transition T1 allowed to go from state S0 to state S1 a with the verification of the conditions listed above, while transition T8 forces a return to state S0 if one of these conditions, except the conditions related to brakes 22, 23, is no longer present. . The transition T8 thus comprises the inverse of each of the conditions of transition T1, except the conditions related to the brakes 22, 23. Thus, if one of the conditions that allowed it to pass to state S1 is no longer pointed out, the unit of shutdown and start control 15 returns to state S0 and automatic shutdown of combustion engine 2 is inhibited. This allows constant monitoring of shutdown conditions.

The transition T2, in turn, leads to state S1 b which is a second sequence of brake control. The transition T2 comprises the following condition:

- parking brake 23 activated.

Thus, a parameter relating to parking brake activation 23 is added to the parameter set being monitored by the presence of transition T8. This parameter can be, for example, the pressure in the parking brake hydraulic circuit 23 which must be above a certain value indicating that this brake is properly activated.

With all conditions of transition T1 checked (implying that transition T8 is not performed) and transition T2 also performed (indicating that parking brake 23 is still on), the shutdown and start control unit 15 goes to state S1 b. The parking brake 23 is now monitored along with the shutdown conditions.

[0074] Figure 5 represents the operations performed in state S1 b relative to a second brake control sequence. This state is initiated by a step E10 that happens shortly after the transition T2 is performed.

In step E1 1, a CT2 counter is initialized as follows: CT2 = 0.

In step E12, the lock brake 22 is deactivated by the stop and start control unit 15, regardless of whether or not it has been activated by the driver. According to the present embodiment, deactivation of the locking brake 22 by the shutdown and start control unit 15 is carried out by an independent control, i.e. by a device such that a series mounted relay of the usual brake command lock 22 (the control which is available to the driver on the vehicle dashboard 1) so that the lock brake 22 can be inhibited by the shutdown and start control unit 15. This provides additional safety in blocking brake inhibition 22.

Step A3 is a first alternative where shutdown and start control unit 15 controls the pressure in the lock brake hydraulic circuit 22 to verify that this pressure is below an activation pressure, indicating that the lock brake 22 is deactivated properly via sensors from the vehicle sensor assembly 1 1. If this is not the case, an interval step E13, which may be two seconds, follows step A3. Then, in an alternative step A4, it is checked that the CT2 counter is equal to 1, and otherwise the process performs a second pass through steps E12 and A3, after incrementing the CT2 counter in step E14.

This allows a second attempt to deactivate lock brake 22 if it was not detected in step A3. After the second attempt, if it is pointed out in step A3 that the locking brake 22 is not yet deactivated, the process goes back to step A4, where it turns out that the counter CT2 is this time equal to 1, which directs the process to failure step E15.

[0079] In step E15, the process is completed with a fault and the shutdown and start control unit 15 signals this fault via bus 12 to motor control unit 8 or vehicle control unit 9, who can then take safety measures regarding the fact that the lock brake 22 does not respond to the deactivation request. Passing the process through fault step E15 has as a first consequence the inhibition of the shutdown and start function so that the shutdown and start control unit 15 no longer automatically shuts off the engine. combustion 2. This fault step E15 may also initiate a signaling of the brake lock failure 22 to the driver by means of a visual or audible signal.

Returning to step A3, if deactivation of lock brake 22 is checked, the process proceeds to step E16 waiting for transition conditions, lock brake 22 being properly deactivated.

From step E15 of state S1 b, two transitions can occur: T9, or T3.

[0082] Transition T9, which leads back to state S0, is identical to transition T8. Thus, if one of the conditions that allowed to switch to states S1 a or S1 b is no longer verified, the shutdown and start control unit 15 returns to state S0 and automatic combustion engine shutdown 2 is inhibited.

Transition T3, in turn, leads to state S2 which is the shutdown state of combustion engine 2. Transition T3 comprises the following condition:

- lock brake 22 deactivated.

In this way, a parameter related to the lock brake deactivation 22 is added to the parameter set being monitored. This parameter can be, for example, the pressure in the lock brake hydraulic circuit 22 which must be below a certain value indicating that this brake is properly deactivated.

With all transition conditions T2 checked (implying that parking brake 23 is still on) and all transition conditions T3 also checked (implying that locking brake 22 is still off), the shutdown and start control 15 goes to state S2.

In state S2, the shutdown control unit and starter 15 turns off the combustion engine 2.

Transition T4 is performed when the combustion engine shutdown 2 is completed, and the process changes to state S3 which is the engine shutdown state.

In state S3, the combustion engine 2 being properly shut off, the start and stop control unit 15 activates the auto off warning lights 26. Thus, the other vehicles around vehicle 1 receive two visually information. : vehicle 1 has combustion engine 2 stopped and therefore cannot move spontaneously; and the combustion engine 2 of vehicle 1 may be automatically switched on at any time by the stop and start device 7.

In state S3, the start and stop control unit 15 also activates the automatic stop and start interface 25 to indicate to the driver that the vehicle engine is shut down due to automatic shutdown.

From state S3, checking the conditions of transition T5, the process goes to state S4 which is a start enable state.

The conditions for performing the T5 transition are as follows in Boolean algebra:

[0092] (C1 a OR C1 b OR C1 c OR ...) AND (C2a AND C2b AND C2c AND ...)

Conditions C1 of the first term of the above formula are main starting conditions while conditions C2 of the second term are secondary starting conditions.

Major conditions C1 are alternative conditions while secondary conditions C2 are cumulative conditions so that the verification of only one of main conditions C1 together with all secondary conditions C2 leads to the realization of the transition. T5

In the present embodiment, the main conditions C1 are as follows:

- C1 a: Main brake pedal 21 operated by the driver; - C1 b: accelerator pedal operated by the driver;

- C1 c: temperature in cabin 4 above a certain comfort temperature, eg 22 ^Q C (indicating that starting the engine is necessary to start the air conditioner);

- C1 d: temperature in cabin 4 below a certain comfort temperature, eg 18 ^Q C (indicating that starting the engine is required to turn the heating on);

- C1 e: combustion engine temperature below a certain operating temperature, eg 60 ^Q C (indicating that the engine is cooling too much);

- C1 f: Battery passing below a certain critical charge (indicating that engine starting is required to charge the battery).

C1 g: Parking brake release command in the off position and lock brake release command in the off position.

In the present embodiment, the secondary conditions C2 are as follows:

- C2a: Cab door (s) 4 closed (s);

- C2b: gear selector in neutral position;

- C2c: driver present in the seat;

- C2d: bucket 3 in normal position (indicating that the vehicle is not maneuvering with the bucket);

- C2e: combustion engine 2 stopped;

- C2f: ambient temperature above a certain critical value, eg -10 ^Q C (temperature below which operation of the electrical system is not guaranteed);

- C2g: parking brake 23 activated;

- C2h: no warning signal activated (motor alert or vehicle alert for whatever reason);

- C2i: shutdown and start contactor 24 activated

(indicating that the driver requires the automatic stop and start function);

- C2j: seat belt of the driver fitted;

- C2k: starter motor 13 operational;

- C2I: slope of the ground less than a certain angle, eg 3 ^Q ;

- C2m: zero vehicle speed.

Bucket condition C2d is an example of the present embodiment, and can be extended to a rest condition, indicating that the vehicle is not maneuvering with any equipment whatsoever.

[0098] Transition T5 being checked, the process goes to start enable state S4. In this state, the start and stop control unit 15 shuts off the starter motor 13 of the vehicle. State S4 ensures that starter 13 will be disabled after condition T1 1 occurs from state S5. Condition T1 1 and state S5 are described below.

From state S4, the process can return to state S3 if transition T10 is performed. This transition T10 includes the inverse of each condition C2 listed above, so that if one of conditions C2 is no longer met, the process returns to state S3 and does not automatically start combustion engine 2. For example, if during In state S4, the driver opens cab door 4 or releases his seat belt, the process returns to state S3.

Otherwise, the transition T6 is checked and the process goes to state S5.

[00101] In state S5, the process can return to state S4 if transition T1 1 is verified. The T1 1 transition contains the same conditions as the T10 transition so that if one of the T1 1 conditions is detected, ie if one of the C2 conditions listed above stops being checked the process returns to state S4 which is executed and , in the absence of another change, returns back to state S3.

State S5, which is the starting state of combustion engine 2, is illustrated in Figure 6. In this state S5, all conditions for an automatic start of combustion engine 2 have been verified, and the steps will be performed. for starting the engine.

State S5 comprises an initiation step E17 followed by an initialization step E18 of a CT3 counter as follows: CT3 = 0.

The process then proceeds to step E19 where a safety horn is triggered. The safety horn warns surrounding vehicles about the imminence of the engine starting the vehicle combustion 1. The safety horn may be the vehicle's main horn 1 or a specific horn of a particular tone and may be fired once or several times. In the present embodiment, in step E19 three short horn horns are performed.

Following this warning, the process proceeds to step E20 where starter motor 13 is started and then alternate step A5 where it is checked whether combustion engine 2 is actually running, ie whether match was properly executed.

If this is not the case, the process retries starting the engine by successively going through step A6, where it is checked whether the counter CT3 is worth 1, and if not, by step E21, where counter CT3 is incremented, and returning to step E19.

If in step A6, the CT3 counter is equal to 1, which means that two unsuccessful combustion engine 2 attempts have already been started, the process goes to failure step E22.

In step E22, the process ends with a fault and the shutdown and start control unit 15 signals this fault via the bus 12 to motor control unit 8 or motor control unit 9, which They can then take safety precautions with respect to the non-starting combustion engine 2. This fault step E22 may also signal the failure of the combustion engine 2 to start by means of a visual or audible signal to the driver.

Returning to step A5, if the combustion engine 2 has started, it is consequently running at idle speed and the process proceeds to step E23 awaiting the transition conditions.

[001 10] The next transition is transition T7 which is satisfied if it is found that the combustion engine is effectively running at idle. To see if this condition is met, it is possible, for example, to check with the combustion engine speed sensor whether the engine is running at more than 500 RPM.

[001 1 1] Transition T7 is an added safety feature to ensure that the motor keeps running, that it has not stopped after step A5 has been checked. If the motor started in state S5 but stopped later, the process does not go to state S0.

After transition T7 is verified, ie that combustion engine 2 is operating normally after automatic start, the process goes to state S0, which is the state of engine running.

[001 13] In state S0, the start and stop control unit 15 will return brake control to the driver. State S0 starts with an initiation step E23 and then goes to step E24 where the auto off warning lights 26 are deactivated. The process then goes on to step E25 in which the driver can be informed that he will resume control of the brakes within a certain range. Optionally, step E25 may be carried out by a "Warning, brake control returns to the driver within 10 seconds" message displayed on the automatic shut-off interface 25.

After the interval indicated in step E25 has elapsed, the process proceeds to steps E26 and E27 in which respectively the lock brake 22 and parking brake 23 return to the position where they were at the time the transition T1 was checked, ie just before the start and stop control unit 15 operates the brakes 22, 23 during states S1 a and S1 b.

In step E28, the driver can be informed that brake control has effectively returned to him. Brake control is returned to the driver, and under the conditions of transition T1, at least one of the two brakes (lock 22 or parking 23) is activated.

Optionally, step E28 may be carried out by a message of type The brakes are now under driver control "displayed to the driver on the automatic start and stop interface 25.

The process then proceeds to step E29 of waiting for the transition conditions so that the process has returned to the state where the present description was initiated. The cycle will start again with transition check T1, as explained above.

Having described a preferred embodiment example, it should be understood that the scope of the present invention encompasses other possible variations, being limited only by the content of the appended claims, including the possible equivalents thereof.

Claims

1 . Process of controlling a stop and start device (7) for the combustion engine (2) of a heavy vehicle (1), including the steps of automatically switching off the combustion engine (2) when shutdown conditions are met and automatically start the combustion engine (2) when starting conditions are met, characterized by the following steps:

- perform a first brake control sequence (S1a) in which a vehicle parking brake (23) (1) is activated;

- add a parking brake activation parameter (23) to the parameter set being monitored;

- performing a second brake control sequence (S1 b) in which a vehicle lock brake (22) (1) is deactivated;

- Adding a parameter relating to the lock brake deactivation (22) to the parameter set being monitored;

- switch off the combustion engine (2).

Process according to claim 1, characterized in that the first brake control sequence (S1 a) includes the verification (A1) that the parking brake (23) is properly activated.

Method according to claim 2, characterized in that, if it is found that the parking brake (23) is deactivated, an additional step of activating the parking brake (23).

A process according to any one of claims 1 to 3, characterized in that the second brake control sequence (S1 b) includes verification (A3) that the lock brake (22) is deactivated properly.

Process according to claim 4, characterized in that it comprises an additional step of deactivating the locking brake (22) if it is found that the locking brake (22) is activated.

Method according to any one of claims 1 to 5, characterized in that if the parking brake (23) is deactivated after the first brake control sequence (S1 a), the combustion engine (2) is prevented from stopping automatically.

Process according to claim 6, characterized in that if the parking brake (23) is deactivated after the first brake control sequence (S1 a), a fault is signaled to the vehicle driver (1). .

Process according to either of Claims 6 and 7, characterized in that if the parking brake (23) is deactivated after the first brake control sequence (S1 a), a parking brake failure ( 23) is signaled on a vehicle network bus (1).

Process according to any one of claims 1 to 8, characterized in that if the lock brake (22) is activated after the second brake control sequence (S1 b), the combustion engine (2) is prevented from stopping automatically.

Process according to claim 9, characterized in that if the lock brake (22) is deactivated after the second brake control sequence (S1 b), a fault is signaled to the vehicle driver (1). .

1 1. Process according to any one of claims 9 and 10, characterized in that if the brake of If lockout (22) is activated after the second brake control sequence (S1 b), a lockout brake failure (22) is signaled on a vehicle network bus (1).

Process according to any one of claims 1 to 11, characterized in that the parking brake (23) is activated independently of its manual actuation.

Process according to any one of claims 1 to 12, characterized in that the locking brake (22) is deactivated independently of its manual actuation.

A method according to any one of claims 1 to 13, characterized in that, after the step of switching off the combustion engine (2), a step of activating lights outside the vehicle (1) of automatic shut-off signaling (26) .

Method according to any one of claims 1 to 14, characterized in that, after the step of switching off the combustion engine (2), a step (E20) of automatically starting the combustion engine (2) when starting conditions a step (E26) in which the parking brake control is returned to the machine driver (1), ie according to the manual parking brake actuation, is checked.

A method according to claim 15, further comprising a step (E27) in which the lock brake control is returned to the machine driver (1), ie according to the manual lock brake actuation. .

Method according to any one of claims 15 and 16, characterized in that it includes a step (E25) for signaling the driver of the vehicle (1) about the return of the brake of parking (23) or locking (22) your starting position.

Method according to any one of claims 15 to 17, characterized in that said verified starting conditions include actuation of the main brake pedal (21) by the driver of the vehicle (1).

Combustion engine shut-off and start-up device (7) (2) for a heavy vehicle (1), implementing the process as defined in any one of claims 1 to 18, characterized in that it includes:

- a shutdown and start control unit (15);

- an independent parking brake control (23) of the vehicle (1), actuated by the shutdown and start control unit (15);

- an independent vehicle lock brake control (22) (1) actuated by the shutdown and start control unit (15).

Device according to claim 19, characterized in that it further includes automatic shut-off external warning lights (26).