FR3103974A1 - Electric charging station - Google Patents

Abstract

The invention relates to an electric charging station comprising a power source, a charging cable and a robotic arm for moving a complementary connector of the electrical outlet of the electrical equipment, and a charge controller detecting electrical continuity. to the terminals for connecting the pilot wire of the battery to be recharged. Said charge controller comprises an operating safety module comprising: a first set of relay (s) of which at least one of the coils is supplied by an electrical circuit comprising an electrical source, and two terminals capable of establishing electrical contact with the terminals connected by the pilot wire of the battery, said first set of relay (s) being open when the electric circuit between the output of the charger and the corresponding electric pole of the battery is closed and by a second set of relay (s) controlled by the motorized arm controller for driving the motorized arm motor in PWM mode. Figure 1

Description

Electric charging station

Field of invention

The present invention relates to the field of conductive electrical charging equipment for mobile equipment such as autonomous vehicles, in particular autonomous handling machines powered by rechargeable batteries.

This equipment usually comprises a charging cable attached to the charger on the charging station, terminated by a connector located at the end of the charging cable complementary to a connector located on the electric vehicle in order to allow the electric battery to be recharged.

For high amperage charging (typically more than 100 amps), it is usual to provide a charge controller to guarantee maximum user safety during charging. This charging controller, on the infrastructure side, conditions the start of the charging on the following tests:

- Verification that the load is well connected to the system

- Verification that the ground of the vehicle is well connected to the protection circuit of the installation

- possibly checking the consistency of the powers between the cable, the vehicle and the charging circuit

- optionally determination of the maximum recharging power which will be allocated to the vehicle.

All of these verifications and communication are done through a communication on a specific wire, called "Pilot wire".

To this end, the connectors of the sockets and socket outlets on the infrastructure side are equipped with two additional wires / pins – called pilot wires.

More particularly, the invention relates to electric vehicle battery charging equipment comprising a robotic arm ensuring the automatic movement of the charging connector and its positioning and connection with the socket of the electric vehicle to be recharged.

State of the art

Known for example in the state of the art is the American patent application US2010289516 describing a malfunction determination solution for a system for charging a battery mounted on a vehicle with electrical energy supplied by a power source external to said vehicle via electric vehicle power equipment. When the vehicle and the power source are mutually coupled, a pilot signal indicates that power can be supplied. The charger of the prior art comprises for this purpose a voltage sensor which detects a voltage of the battery of the vehicle and a control unit which determines whether or not there is a malfunction, in accordance with an output state of said pilot signal and at the detected voltage.

US patent US5596258 describes another example of a charging device for a battery-powered electric vehicle, comprising:

a) a charger having a power supply;

b) communication means, installed both in the charger and in the electric vehicle, for transmitting and receiving information on a charging operation from and to the charger and the electric vehicle;

c) an anomaly detection means for detecting if an anomaly occurs in the communication between the charger and the electric vehicle; And

d) control means for performing charging on the battery of the electric vehicle in accordance with a previously defined special charging protocol when the abnormality detecting means detects the abnormality in the communication between them.

Also known in the state of the art is European patent application EP2564486A4 describing a system for connecting an electric vehicle to a charging station comprising:

- a charging station with a charging interface, a signal receiver and one or more sensors;

- an electric vehicle comprising a contact plate configured to form an electrical connection with the charging interface and a signal transmitter configured to communicate with the signal receiver; wherein said sensors detect a position of the electric vehicle relative to the charging station.

Also known in the state of the art is the international patent application WO2017103250 describing another example of a method for executing energy supply processes between at least one energy supply unit and several vehicles to be supplied with energy. . The power supply interface of the power supply unit is moved by a robot towards the power supply interface of the vehicle and coupled thereto.

US patent US9266440 describes another example of a robotic charging station for charging a battery of an electric vehicle, the charging station comprising: a base plate, a riser coupled to the base plate and extending substantially transversely to the baseplate, a robotic arm extending from the riser and supporting an end effector. The robotic arm is configured to move the connector through three degrees of motion. A target tracking camera integrated into the end effector is configured to periodically produce a captured image. A controller is configured to receive the captured image from the target tracking camera, identify a pattern on the electric vehicle from the received captured image, determine a spatial relationship between the end effector and an electric receptacle disposed on the electric vehicle from at least one of a size, an inclination or a position of the pattern in the captured image.

Disadvantages of the prior art

The solutions of the prior art are not completely satisfactory because they leave security flaws: risk of crushing of the hand interposed between the socket and the battery when moving the motorized arm, risk of operation in the absence of battery or bad connection,…

Solution provided by the invention

In order to remedy these drawbacks, the invention relates, in its most general sense, to an electric charging station comprising an energy source, a charging cable and a robotic arm ensuring the movement of a complementary connector of the electrical outlet of the electrical equipment, and a charge controller detecting the electrical continuity at the connection terminals to the pilot wire of the battery to be recharged, characterized in that the said charge controller comprises an operating safety module comprising:

- a first set of relay(s) of which at least one of the coils is powered by an electrical circuit comprising an electrical source, and two terminals capable of establishing electrical contact with the terminals connected by the pilot wire of the battery, said first set of relay(s) being opened when the electrical circuit between the output of the charger and the corresponding electrical pole of the battery is closed

- And by a second set of relay(s) controlled by the controller of the motorized arm for controlling the motor of the motorized arm in PWM mode.

According to different variants, taken individually or in a technically compatible combination,

- Said first set of relays comprises a first relay and a second relay, the two coils of said relays being connected in parallel.

- the coil of at least one of the relay(s) of said first set of relay(s) is connected on the one hand to the secure ground corresponding to the security line of a contact detection edge, and on the other hand at the output of the controller controlling the extension of said motorized arm.

- the power terminal of said first relay connected to the motor controlling the extension of said motorized arm, the normally closed terminal being connected to the motor supply circuit, the normally open terminal being connected to the power terminal of said second relay

- the normally open terminal of said second relay is connected to the coil of one of the relays of said second set and to the normally open terminal of another relay of said second set.

- the power terminal of the third relay (43) is connected to the second connection of the motor, said third relay controlling the withdrawal of the motorized arm, its coil being connected between ground and the controller controlling the retraction of the arm

- a fourth relay controls the switching of the power supply, its coil being connected between ground and the power terminal of a fifth relay

- the power terminal of the fourth relay is connected to the normally open terminals of the second relay and the third relay

- the coil of a fifth relay is connected between a battery presence detection circuit and the output of the motorized arm retraction controller.

Detailed description of a non-limiting example of the invention

The present invention will be better understood on reading the detailed description of a non-limiting example of the invention which follows, with reference to the appended drawings where:

Figure 1 shows a top view of a charging station according to the invention

Figure 2 shows a front view of a load plate according to the invention

Figure 3 shows the simplified electrical diagram of the invention

FIG. 4 represents the electrical diagram of the control circuit of the invention

Hardware Architecture

The charging station described as an example in the following is a robot-controlled charging system for electric robot forklifts, which makes it possible to charge robot forklifts autonomously.

The charging station comprises a docking station (1) containing the electrical and electronic circuits as well as an actuation system for a charging plate (2) supported by a retractable arm (3).

The electrical and electronic circuits include a control system, a sensor identification system, an electrical system and a communication system.

The docking station in the example described has a first power supply for the retractable arm actuating motor and a second independent power supply for the electrical and electronic circuits. It has five buttons:

o a button (4) for the circuit breaker,

o a button (5) to switch on/off,

o a button (6) for the emergency stop,

o a button (7) to reset,

o a button (8) to reach/to retract,

o a button (9) key for manual / auto mode

The docking station also has a retro-reflex sensor and four safety edges with one or more sensors that deliver an electrical signal in the event of contact with an obstacle or a person.

The presence identification system comprises an optical sensor for detecting the vehicle to be recharged, and mechanical sensors, which collect information relating to contact with an obstacle or a person.

The communication system includes network and wireless communication, for transmitting signals with a server.

The control system consists of the electronic board controlling the movements of the robotic arm and the electrical board.

The actuation system is mainly composed of a load plate (2), a linear motor and its control system, whose role is to act as a moving load robot arm.

The load plate (2) is shown in Figure 2 front view. It comprises an electrical power contact (10) corresponding to the electrical ground, and an electrical power contact (11) corresponding to the +48 V positive pole.

It also comprises two electrical contacts (12, 13) corresponding to the detection of the presence of the battery (in English “interlock”) and two electrical contacts (14, 15) for controlling the plate (2) by a digital signal.

The electrical power contacts (10, 11) consist of masses of copper, for example pairs of crossbars to allow the passage of strong currents.

The electrical contacts (12 to 14) are copper plates for the passage of less important currents. They correspond to complementary contacts on the battery (21), which are connected by a short-circuit link (22) in the battery.

The electrical system comprises a charger (30) with a pair of electric cables (31, 32) for the power current 48 V connecting the charger (30) to the charging station (1), a pair of conductors (33, 34) for digital service signals, and a pair of conductors (35, 36) for checking the presence of a battery.

It comprises a main board (25) receiving the signals from the external sensors, from the battery presence detection line (35, 36) and the control signals delivered by the charger (1) on the line (33, 34) to control the motor (28) of the motorized arm (2) via a circuit (26) as well as the relays (27) controlling the power supply.

The docking station is connected to a battery charger (30) (24V, 400A), the power outlet (220V or 110V depending on the country). The charging plate (3) presses against the charging plate (20) of the battery (21) under the action of the motorized arm (2).

Automatic mode

When the charging station operates in automatic mode, it allows two operations.

The first operation concerns the engagement of the charging socket on the vehicle to be recharged. The system receives the activation command from an external device.

The system waits for the presence of the robot whose relative position is provided by the aforementioned detection sensor.

When the presence of the vehicle is detected, the arm (3) supporting the charging plate (2) is deployed (using the access order) until the locking of the battery is detected;

When battery lockout is detected, a final push is performed to ensure sufficient force is exerted on the electrical contacts. When the contact force is reached, the charger lock line is activated. Charging then begins automatically.

The second operation concerns withdrawal.

The system receives the deactivation order. There system then deactivates the charger lock line. Charging stops automatically. The system monitors the charger current and waits for the current to drop to 0 amps. The arm then retracts until the retract stop is reached.

External control mode

According to a second operating mode, the charging station receives commands transmitted by external peripherals.

The two types of operation described with reference to automatic mode can be enabled or disabled by a configuration parameter transmitted by an external device.

This parameter can be transmitted by network communication. The system is then equipped with an Ethernet connection and the ModBus protocol for communication with the associated vehicle server.

MANUAL MODE

In manual mode, there are two possible operations:

The first operation concerns the engagement of the charging socket on the vehicle to be recharged.

If the control button is activated, the arm extends (using the reach control) until the button is released or the battery lock is detected or the reach stop is reached.

When battery lock is detected, the “last press” is performed to ensure sufficient force is exerted on the electrical contacts (only if the reach button is still active).

When the contact force is reached, the charger lock line is activated

Charging should begin automatically

Retraction operation:

If the retract control button is activated, the system disables the magazine lock line if it is active.

Charging should stop automatically

The system monitors the charger current and waits for the current to drop to 0 amps.

The arm retracts until the button is released or the retract stop retracts if reached.

SECURITY: DEFAULT MANAGEMENT

- If the commands to engage the socket and to withdraw the socket are received at the same time, no operation is authorized.

- If the retract command is received while the scope is in progress, the scope must be stopped and the retract action performed

- If the reach command is received while the retract is in progress, the retract movement must continue until the final stop is reached, if the reach command is still active, the action of reached can be performed.

- If the reach movement is executed and the reach stop is reached, the docking station must signal an error and initiate an automatic retraction procedure.

- If an actuation is requested and the current consumption of the actuator is too low, the system must report an error.

- If an actuation is requested and the current consumption of the actuator is too high (short circuit), the system must report an error.

- If an actuation is requested and the final stop is not reached before a TimeOut parameter, the system must signal an error. The list of error signals is as follows:

o Category 1: Automatic erasure

o Category 2: manual deletion

o Category 3: Power cycle required to clear patch plate

o Category 4: service intervention required.

The electronic circuit includes a computer controlling the following functions:

- In automatic mode, no reach actuation is allowed if the retro-reflex sensor is not active

- If the reach stop sensor is active, all reach actuations are prohibited

- If the retract stop sensor is active, any retract actuation is prohibited

- Using current measurements, the system should be able to estimate the effort produced by the arm:

o If the current is too high and the battery lock is not active, a 1 second automatic removal must be performed and the system reports an error.

o If battery lock is active, this estimate should be used to ensure sufficient contact force

o Any activation of the actuator (Reach or Retract) must be done with a linear increase in current via PWM control.

power control

Operating safety is ensured by two sub-assemblies of electromechanical relays represented in figure 4.

The first relay sub-assembly consists in the example described of two relays (41, 42) whose coils are supplied in parallel. This first sub-assembly controls the secure extension of the motorized arm (2).

The second sub-assembly of relays consists in the example described of three relays (43 to 45).

The coils of the two relays (41, 42) of the first sub-assembly are supplied on the one hand by a secure ground controlled by the safety barrier (46). If this safety barrier (46) is touched, the power supply is interrupted.

They are powered on the other hand by the output of the controller (47) delivering the PMW pulse width modulation signal controlling the extension of the motorized arm (2).

One of the connections of the motor (28) controlling the extension of the arm is connected to the power terminal of the first relay (41).

The normally closed terminal of the first relay (41) is connected to the controller (46), and the normally open terminal of the first relay (41) is connected to the power terminal of the second relay (42).

The normally closed terminal of the second relay (42) is left open.

The normally open terminal of the second relay (42) is switched power corresponding to the power terminal of the fourth relay (44) and the normally open terminal of the third relay (43).

The power terminal of the third relay (43) is connected to the second motor connection (28). This third relay (43) controls the withdrawal of the motorized arm (2).

Its coil is connected between ground and the controller (48) controlling the retraction of the arm (2).

The fourth relay (44) controls the switching of the power supply. The coil is connected between ground and the power terminal of the fifth relay (45). The power terminal of the fourth relay (44) is connected to the normally open terminals of the second relay (42) and the third relay (43).

The coil of the fifth relay (45) is connected between a circuit (49) for detecting the presence of the battery and the output of the controller (48) for retracting the motorized arm (2). The power terminal of the fifth relay (45) is connected to the battery presence detection line, the normally closed terminal is open circuit and the normally open terminal corresponds to a battery detection signal.

Claims (8)

– Electrical charging station comprising an energy source, a charging cable and a robotic arm ensuring the movement of a complementary connector of the electrical outlet of the electrical equipment, and a charge controller detecting the electrical continuity at the terminals of connection to the pilot wire of the battery to be recharged, characterized in that the said charge controller comprises an operating safety module comprising:
- a first set of two relays, said first relay (41) and second relay (42), at least one of the coils of which is powered by an electric circuit comprising an electric source, and two terminals able to establish an electric contact with the terminals connected by the pilot wire of the battery, said first set of relay(s) being open when the electric circuit between the output of the charger and the corresponding electric pole of the battery is closed
- And by a second set of three relays, said third relay (43), fourth relay (44), fifth relay (45) controlled by the controller of the motorized arm for controlling the motor of the motorized arm in PWM mode. – Electric charging station according to claim 1 characterized in that said first set of relays comprises a first relay and a second relay, the two coils of said relays being connected in parallel. – Electric charging station according to claim 1 characterized in that the coil of at least one of the relay(s) of said first set of relay(s) is connected on the one hand to the secure ground corresponding to the safety line of a contact detection border, and on the other hand at the output of the controller controlling the extension of said motorized arm. – Electric charging station according to claims 2 and 3 characterized in that
- the power terminal of said first relay is connected to the motor controlling the extension of said motorized arm, the normally closed terminal being connected to a first connection of the motor, the normally open terminal being connected to the power terminal of said second relay
- And in that the normally open terminal of said second relay is connected to the coil of one of the relays of said second set and to the normally open terminal of another relay of said second set. – Electric charging station according to claims 3 and 4, characterized in that the power terminal of the third relay (43) being connected to a second connection of the motor (28), said third relay (43) controlling the withdrawal of the motorized arm (2), its coil being connected between ground and the controller (48) controlling the retraction of the arm (2). – Electric charging station according to claim 1 characterized in that a fourth relay (44) controls the switching of the power supply, its coil being connected between ground and the power terminal of a fifth relay (45). – Electric charging station according to the preceding claim characterized in that the power terminal of the fourth relay (44) is connected to the normally open terminals of the second relay (42) and the third relay (43). – Electric charging station according to claim 1 characterized in that the coil of a fifth relay (45) is connected between a circuit (49) for detecting the presence of the battery and the output of the controller (48) for retracting the arm motorized (2).